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Studies on Nickel Metabolism: Interaction with Other Mineral Elements1
METABOLISM AND NUTRITION Studies on Nickel Metabolism: Interaction with Other Mineral Elements1 J. R. LING and R. M. LEACH, JR. Department of Poultry Science, The Pennsylvania State University, University Park, Pennsylvania 16802 (Received for publication April 3, 1978)
1979 Poultry Science 58:591-596 INTRODUCTION During recent years considerable interest has developed in b o t h t h e essentiality and t h e toxicity of nickel. Nielson and Ollerich ( 1 9 7 4 ) reviewed t h e evidence t h a t suggests t h a t nickel b e considered an essential element. Diets containing 20 p p b or less nickel resulted in t h e occurrence of several abnormalities which could b e reversed by t h e addition of nickel to the diet. R e c e n t l y , Schnegg and Kirchgessner ( 1 9 7 5 a , b ; 1976a) have presented further evidence for t h e essentiality of nickel for normal growth and h e m o globin f o r m a t i o n in t h e y o u n g rat. Interest in nickel toxicity has been stimulated b y t h e general increase in awareness of possible e n v i r o n m e n t a l c o n t a m i n a n t s . A diet of 1 6 0 0 p p m nickel was sufficient t o cause a r e d u c t i o n of g r o w t h and a lowering of food c o n s u m p t i o n in mice (Weber and Reid, 1 9 6 9 ) . However, dietary levels of nickel u p t o 1 0 0 0 p p m had n o effect on g r o w t h or r e p r o d u c t i o n in rats (Phatak and P a t w a r d h a n , 1950). In a subseq u e n t s t u d y , y o u n g rats fed a ration containing 2 5 0 p p m nickel for 16 m o n t h s grew n o r m a l l y (Phatak and P a t w a r d h a n , 1 9 5 2 ) . Y o u n g chicks appear t o be m o r e sensitive t o nickel t o x i c i t y ,
1
This paper was approved for publication as paper no. 5478 in the journal series of the Pennsylvania Agricultural Experiment Station.
since Weber and Reid ( 1 9 6 8 ) have r e p o r t e d t h a t 700 mg/kg will result in g r o w t h r e t a r d a t i o n . T h e p u r p o s e of this investigation was t o determine t h e relationship b e t w e e n dietary nickel c o n t e n t a n d tissue nickel distribution. F u r t h e r m o r e , due t o t h e widespread n a t u r e of interactions in trace mineral n u t r i t i o n , it seemed a p p r o p r i a t e t o d e t e r m i n e t h e effect of other m e t a l elements on nickel t o x i c i t y a n d tissue nickel distribution. MATERIALS AND METHODS T h r e e studies were carried o u t w i t h day-old White P l y m o u t h R o c k male chicks. T h e y were housed in b a t t e r y b r o o d e r s with raised wire floors. Feed and distilled water were supplied ad libitum. Duplicate groups of eight chicks each were fed t h e e x p e r i m e n t a l diets. In t h e first e x p e r i m e n t , nickel, as nickel chloride, was a d d e d t o a purified basal diet of glucose a n d isolated s o y p r o t e i n (Leach a n d Nesheim, 1 9 6 5 ) . T h e additions were m a d e in order t o supply 0, 300, 500, 7 0 0 , 9 0 0 , a n d 1 1 0 0 m g / k g nickel in t h e ration, assuming a negligible a m o u n t of nickel in t h e basal diet itself. In E x p e r i m e n t 2, t h e 500 mg/kg nickel diet was fed alone and w i t h additions of 1 0 0 m g / k g of either cobalt, zinc, copper, o r iron. Experim e n t 3 consisted of feeding t h e basal diet alone and s u p p l e m e n t e d w i t h 50, 1 0 0 , 2 0 0 m g / k g
591
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015
ABSTRACT Nickel toxicity was studied in young chicks fed a semi-purified diet. Dietary nickel concentrations of 300 mg/kg and higher resulted in significant reduction in growth rate. Mortality and anemia were observed in chicks receiving 1100 mg/kg nickel. Dietary nickel content of 300 mg/kg resulted in a significant increase in kidney nickel content while higher dietary levels were required to affect the nickel content of other body tissues. Supplementation of nickel toxic diets (500 mg/kg) with 100 mg/kg of cobalt, iron, copper, and zinc did not alleviate the symptoms of nickel toxicity or consistently affect tissue nickel accumulation. The addition of cobalt resulted in a further depression in growth rate when added to the nickel toxic diet. However, subsequent studies showed that this was due to the toxicity of cobalt and no evidence was found for an interaction between these two elements. The lack of interaction of nickel with copper, iron, and zinc is in contrast to the results observed by other investigators at low dietary concentrations of nickel.
592
LING AND LEACH
RESULTS The results of feeding graded levels of nickel
TABLE 1. Effect of nickel in the diet on tissue nickel levels, body weights, hemoglobin concentrations, and hematocrit values Level of nickel supplementation (ppm)
3 Week weight, g Survivors'1 Hemoglobin concentration, mg% Hematocrit
0
300
500
700
900
1100
472.0 b 16 7.89 c 30.0
404.6 C 15 7.39 c 30.5
297.9 d 12 7.38 c 30.3
204.6 e 13 7.36 c 30.9
117.9 f 8 7.05bc 30.0
80.4 f 8.57 5 6.07 b .27 27.1 .97
b
b
Tissue Muscle Heart Liver Bone Kidney
SE*
MgN i/g wet tissue .14 .14 b .10 b .10 b .13b
.26 .31bc .36 b .97bc 4.23 c
44b c .5ic .69 c 1.88 c 7.65 d
.60 c .80 d .99 d 3.75 d 9.73 e
1.52 d 1.39 e 2.04 e 4.93de 11.15 f
2.62 e 1.50e 1.43 f 5.91 e 11.48 f
.07 .05 .06 .30 .02
Standard error of pooled means, four samples per treatment. g Within each row, those values not followed by the same letter are significantly different at the 5% probability level. Originally 16 birds per treatment.
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015
to young chicks are presented in Table 1. Nickel in quantities of 300 mg/kg of diet and greater significantly reduced growth rate. The diets containing 900 and 1100 mg/kg nickel also proved to be quite toxic. Of the tissues studied, the kidney proved to be the most sensitive tissue with respect to nickel accumulation. Even at the 300 mg/kg level there were substantial increases in the nickel content of the tissue. Kidney nickel content tended to plateau at the higher dietary levels when other tissues started to show substantial amounts of nickel accumulation. Based upon the results obtained in Experiment 1, the level of 500 mg/kg was selected for the study of possible interactions in Experiment 2. These results are presented in Table 2. Cobalt, zinc, copper, and iron (100 mg/kg) were tested for their ability to alleviate nickel toxicity. The addition of copper, zinc, and iron did not alleviate the growth depression caused by nickel toxicity. Iron, copper, and zinc did not produce a consistent affect on the deposition of nickel tissues. However, there were significant changes in the nickel content of certain tissues associated with the feeding of these elements. The addition of cobalt to the nickel containing diet resulted in a further depression in growth rate and blood hemoglobin concentration. The nickel content of the kidney was also significantly increased by the
cobalt, 500 mg/kg nickel alone and with addition of 50, 100, 200 mg/kg cobalt. All birds were weighed and examined physically at weekly intervals. At 3 weeks of age, the chicks were killed and autopsied. Immediately prior to this, blood samples were taken by cardiac puncture from four randomly selected birds from each treatment replicate. Microhematocrit and hemoglobin determinations (by the method of Van Kampen and Zijlstra, 1961) were performed within 24 hr of collection. Specimens of liver, kidney, breast muscle, and leg bone were collected from the same eight chicks. Tissue samples were pooled and stored at —65 C prior to nickel analysis. The nickel content of these samples was determined in quadruplicate by the method of Nomoto and Sunderman (1970). The samples were initially digested with a mixture of nitric and sulfuric acid (5:1) followed by the addition of a mixture of nitric, sulfuric, and perchloric acids (10:2:1). Recovery data were obtained for each tissue analyzed. Average recovery was 95% (range 85 to 103). All results were examined by analysis of variance, and statistically significant differences among treatments were determined by the Q method described by Snedecor and Cochran (1967).
NICKEL TOXICITY AND METABOLISM
593
TABLE 2. Effect of cation additions to a nickel toxic diet on tissue nickel levels, body weights, hemoglobin concentrations, and hematocrit values Level of nickel and cation supplianentation (ppm)
3 Week weight, g Survivors" Hemoglobin concentration, mg% Hematocrit
0
500Ni
500Ni + 100CO
500Ni + lOOZn
500Ni + lOOCu
500Ni + lOOFe
397.ld 16 7.77 c 31.6
248.1 c 15 7.10 c 30.5
131.7 b 13 5.46 b 28.7
230.2 C 14 6.98 c 31.8
257.4 C 14 6.88 c 30.2
271.4 C 16 7.55 c 33.3
12.17
.12t> .13b .10b .13b
d
.51d .35 d .45C 7.03 c
.03 .02 .07 .01
.30 1.02
Mg Ni/g wet tissue
Muscle Heart Liver Kidney
.51 .52 e .72«i 7.93 e
.59 d .43d 1.01 d 10.80 f
.36 c .57 e .88 d 12.588
.48cd .26 c .55 c 7.73 d
Standard error of pooled means, four samples per treatment. ^Within each row, those values not followed by the same letter are significantly different at the 5% probability level. Originally 16 birds per treatment.
cobalt treatment. These results suggested that cobalt enhanced nickel toxicity. Experiment 3 was designed to study the possible cobalt-nickel interaction in more detail. Results are presented in Table 3. In this experiment, levels of cobalt of 50, 100, and 200 mg/kg were fed alone and in combination with 500 mg/kg of nickel. Feeding 100 and 200 mg of cobalt to chicks resulted in significant depressions in growth rate. Further decreases in growth rate were observed when cobalt was added to diets containing nickel. As was observed in the previous experiment, two of the three cobalt treatments did result in increases in the nickel content of the kidneys from chicks fed 500 mg/kg of nickel. However, there was no consistent effect of the cobalt treatments on the nickel content of the liver. The effect of cobalt on tissue nickel concentration does not appear to be of sufficient consistency or magnitude to account for the growth depressing effects of this element above or in the presence of nickel. Thus, it appears that both cobalt and nickel are toxic and that the effects are additive.
DISCUSSION A significant depression in body used as the primary criterion for nickel toxicity. And 300 mg/kg nickel chloride, produced this
weight was a state of nickel, as depression
when compared to the control birds. Weber and Reid (1968) found a significant growth reduction at 700 mg/kg nickel and above. The variance may be largely due to the fact that they used a non-purified diet. Other contributors might be the nickel salt (sulphate or acetate) and the breed of chicks used. Certainly, the present study produced markedly greater growth reduction, for at 500 mg/kg nickel the chicks weighed 57% less than the controls, whereas the equivalent figure from the data of Weber and Reid was 19%. Concurrent with the highly toxic (especially 900 and 1100 ppm) levels was a high rate of mortality, although the actual causes of death were not determined. The survivors in these treatments appeared to be normal in every respect except for their diminuitive size and juvenile appearance. No specific symptoms of any nutrient deficiency were observed, and therefore, it seemed that nickel toxicity did not precipitate any deficiencies. O'Dell et al. (1970) also considered nickel toxic calves to resemble younger animals in appearance and put forward the possibility of a relationship between nickel and growth hormones. Labella et al. (1973) reported that prolactin secretion was inhibited by high tissue concentrations of nickel. As expected when dietary nickel increased, so did tissue nickel. Bone and kidney accumulated the greater amounts, especially the latter
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015
Tissue
SE a
.10° .14°
.ll .15b
b
373.8 f 15 7.53 c 30.1
430.6 f 16 6.93bc 30.6
,12 .15b
.lib .13b
166.2 b c 15 6.60bc 24.6 Mg Ni/g
258.7 d e 15 7.03bc 28.9
b
200Co
lOOCo
.68 c 7.43 d
wet tissue
283.2^ 15 8.35C 29.7
500Ni
.84 c d 7.95 e
202.3cd 10 7.82bc 28.2
500Ni + 50Co
^Originally 16 birds per treatment.
Standard error of pooled means, four samples per treatment, b-f, Within each row, those values not followed by the same letter are significantly different at the 5% probability level.
Liver Kidney
Tissue
3 Week weight, g Survivors? Hemoglobin concentration, mg% Hematocrit
50Co
0
Level of nickel and cobalt supplementation (ppm)
TABLE 3. Effect of cobalt additions to a nickel toxic diet on tissue nickel levels, body weights, hemoglobin concentrations, and hematocrit values
ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015 .99d 8.78 f
128.8 b c 14 6.42b 24.0
500Ni + lOOCo
.75 c 6.67 c
96.3b 10 4.90 b 23.1
500Ni + 200Co
.05 .05
.60 1.08
17.96
SEa
X
> n
Z D r en
r Z >
NO
NICKEL TOXICITY AND METABOLISM
(Schnegg and Kirchgessner, 1975b). Further studies by Schnegg and Kirchgessner (1976a) led to the conclusion that iron absorption was inhibited during nickel deficiency. These investigators (Schnegg and Kirchgessner, 1976b) have also suggested an interaction of nickel with copper and zinc. This conclusion is based upon the observation that nickel deficiency was associated with decreased levels of iron, copper, and zinc in the liver, spleen, and kidneys. Thus, nickel does interact with other elements at low dietary concentrations, although these elements had no effect on the course of nickel toxicity in the studies reported here.
REFERENCES Labella, F. S., R. Dular, P. Lemon, and G. Queen, 1973. Prolactin secretion-inhibition by nickel. Nature 245:3 3 0 - 3 32. Leach, R. M., Jr., and M. C. Nesheim, 1965. Nutritional, genetic and morphological studies of an abnormal cartilage formation in young chicks. J. Nutr. 86:230-244. Nielsen, F. H., and D. A. Ollerich, 1974. Nickel: A new essential trace element. Fed. Proc. 33:1767-1774. Nomoto, S., and F. W. Sunderman, Jr., 1970. Atomic absorptive spectrometry of nickel in serum, urine and other biological materials. Clin. Chem. 16:477-485. O'Dell, G. D., W. J. Miller, W. A. King, S. L. Moore, and D. M. Blockman, 1970. Nickel toxicity in the young bovine. J. Nutr. 100:1444—1453. Phatak, S. S., and V. N. Patwardhan, 1950. Toxicity of nickel. J. Sci. Ind. Res. 9b:70-76. Phatak, S. S., and V. N. Patwardhan, 1952. Toxicity of nickel: accumulation of nickel in rats on nickelcontaining diets and its elimination. J. Sci. Ind, Res. l l b : 1 7 3 - 1 7 6 . Schnegg, A., and M. Kirchgessner, 1975a. Essentiality of nickel for the growth of animals. Z. Tierphysiol. Tierern'ah. Futtermittelkiende 36:63-74. Schnegg, A., and M. Kirchgessner, 1975b. Changes in the homoglobin content, erythrocyte content and hematocrit in nickel deficiency. Nutr. Metab. 19:268-278. Schnegg, A., and M. Kirchgessner, 1976a. Absorption and metabolic efficiency of iron during nickel deficiency. Int. J. Vitamin Nutr. Res. 46:96—99. Schnegg, A., and M. Kirchgessner, 1976b. Interaction of nickel with iron, copper and zinc. Archiv. fur Tierenahrung 26:543 — 549. Snedecor, G. W., and W. G. Cochran, 1967. Page 2 7 2 - 2 7 3 . Statistical methods. 6th ed. The Iowa State University Press, Ames, IA. Spears, J. W., E. E. Hatfield, and R. M. Forbes, 1977. Nickel-copper interrelationship in the rat. Proc. Soc. Exp. Biol. Med. 156:140-143. Sunderman, F. W., Jr., 1977. A review of the metabolism and toxiology of nickel. Ann. Clin. Lab. Sci. 7:377-398.
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organ. This is in concert with other studies on nickel distribution and the observation that nickel is excreted in the urine (Sunderman, 1977). As little as 300 mg/kg resulted in a significant rise in kidney nickel content. However, the dramatic increases in kidney nickel appeared to plateau at about 900 mg/kg dietary level, as if this organ were reaching a saturation peak. Simultaneous with this was a large increase in muscle nickel content together with a continuous rise in bone nickel concentration. It may be that at this level, around 1000 mg/kg nickel, the urinary excretion mechanism is overloaded and cannot cope with increased absorption of dietary nickel. The result could be influx into all other body tissues, especially muscle, where a small concentration increase represents a large absolute increase. The cations (Co, Cu, Zn, Fe) used in an attempt to counteract nickel toxicity were chosen with reference to the periodic table, thereby increasing the likelihood of an interaction between chemically similar elements. The addition of 100 mg/kg of these elements produced no well defined patterns. Although these elements did result in some changes in tissue nickel content, none of these elements produced a consistent pattern which would be indicative of an interaction between one of these elements and nickel. Furthermore, none of the other criteria measured suggested that there was an interaction between these elements and nickel. The growth depression observed with addition of cobalt appears to be due to the toxicity of cobalt independent of an effect upon nickel toxicity. The toxicity of cobalt and nickel appeared to be additive. Thus, it is concluded that the effects of nickel toxicity are not due to an effect of this element on the metabolism of cobalt, copper, iron, or zinc. First of all, dietary additions of these elements did not reverse the course of nickel toxicity. Secondly, the symptoms of nickel toxicity did not resemble deficiency symptoms characteristic for these elements. These results are in contrast to recent observations made at low dietary concentrations of nickel. Spears et al. (1977) found that nickel supplementation to a copper deficient diet resulted in increased weight gain and blood hematocrits. This response to nickel was observed only with the copper deficient diet and not with diets containing adequate amounts of copper. It also has been reported that nickel deficiency results in anemia
595
596
LING AND LEACH
Van Kampen, E. J., and W. G. Zijlstra, 1961. Standardization of hemoglobinometry. II. The hemiglobinezamide method. Clin. Chem. Acta 6:538-544.
Weber, C. W., and B. L. Reid, 1968. Nickel toxicity in growing chicks. J. Nutr. 95:612—616. Weber, C. W., and B. L. Ried, 1969. Nickel toxicity in young growing mice. J. Anim. Sci. 28:620—623.
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015
1979 Poultry Science 58:591-596 INTRODUCTION During recent years considerable interest has developed in b o t h t h e essentiality and t h e toxicity of nickel. Nielson and Ollerich ( 1 9 7 4 ) reviewed t h e evidence t h a t suggests t h a t nickel b e considered an essential element. Diets containing 20 p p b or less nickel resulted in t h e occurrence of several abnormalities which could b e reversed by t h e addition of nickel to the diet. R e c e n t l y , Schnegg and Kirchgessner ( 1 9 7 5 a , b ; 1976a) have presented further evidence for t h e essentiality of nickel for normal growth and h e m o globin f o r m a t i o n in t h e y o u n g rat. Interest in nickel toxicity has been stimulated b y t h e general increase in awareness of possible e n v i r o n m e n t a l c o n t a m i n a n t s . A diet of 1 6 0 0 p p m nickel was sufficient t o cause a r e d u c t i o n of g r o w t h and a lowering of food c o n s u m p t i o n in mice (Weber and Reid, 1 9 6 9 ) . However, dietary levels of nickel u p t o 1 0 0 0 p p m had n o effect on g r o w t h or r e p r o d u c t i o n in rats (Phatak and P a t w a r d h a n , 1950). In a subseq u e n t s t u d y , y o u n g rats fed a ration containing 2 5 0 p p m nickel for 16 m o n t h s grew n o r m a l l y (Phatak and P a t w a r d h a n , 1 9 5 2 ) . Y o u n g chicks appear t o be m o r e sensitive t o nickel t o x i c i t y ,
1
This paper was approved for publication as paper no. 5478 in the journal series of the Pennsylvania Agricultural Experiment Station.
since Weber and Reid ( 1 9 6 8 ) have r e p o r t e d t h a t 700 mg/kg will result in g r o w t h r e t a r d a t i o n . T h e p u r p o s e of this investigation was t o determine t h e relationship b e t w e e n dietary nickel c o n t e n t a n d tissue nickel distribution. F u r t h e r m o r e , due t o t h e widespread n a t u r e of interactions in trace mineral n u t r i t i o n , it seemed a p p r o p r i a t e t o d e t e r m i n e t h e effect of other m e t a l elements on nickel t o x i c i t y a n d tissue nickel distribution. MATERIALS AND METHODS T h r e e studies were carried o u t w i t h day-old White P l y m o u t h R o c k male chicks. T h e y were housed in b a t t e r y b r o o d e r s with raised wire floors. Feed and distilled water were supplied ad libitum. Duplicate groups of eight chicks each were fed t h e e x p e r i m e n t a l diets. In t h e first e x p e r i m e n t , nickel, as nickel chloride, was a d d e d t o a purified basal diet of glucose a n d isolated s o y p r o t e i n (Leach a n d Nesheim, 1 9 6 5 ) . T h e additions were m a d e in order t o supply 0, 300, 500, 7 0 0 , 9 0 0 , a n d 1 1 0 0 m g / k g nickel in t h e ration, assuming a negligible a m o u n t of nickel in t h e basal diet itself. In E x p e r i m e n t 2, t h e 500 mg/kg nickel diet was fed alone and w i t h additions of 1 0 0 m g / k g of either cobalt, zinc, copper, o r iron. Experim e n t 3 consisted of feeding t h e basal diet alone and s u p p l e m e n t e d w i t h 50, 1 0 0 , 2 0 0 m g / k g
591
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015
ABSTRACT Nickel toxicity was studied in young chicks fed a semi-purified diet. Dietary nickel concentrations of 300 mg/kg and higher resulted in significant reduction in growth rate. Mortality and anemia were observed in chicks receiving 1100 mg/kg nickel. Dietary nickel content of 300 mg/kg resulted in a significant increase in kidney nickel content while higher dietary levels were required to affect the nickel content of other body tissues. Supplementation of nickel toxic diets (500 mg/kg) with 100 mg/kg of cobalt, iron, copper, and zinc did not alleviate the symptoms of nickel toxicity or consistently affect tissue nickel accumulation. The addition of cobalt resulted in a further depression in growth rate when added to the nickel toxic diet. However, subsequent studies showed that this was due to the toxicity of cobalt and no evidence was found for an interaction between these two elements. The lack of interaction of nickel with copper, iron, and zinc is in contrast to the results observed by other investigators at low dietary concentrations of nickel.
592
LING AND LEACH
RESULTS The results of feeding graded levels of nickel
TABLE 1. Effect of nickel in the diet on tissue nickel levels, body weights, hemoglobin concentrations, and hematocrit values Level of nickel supplementation (ppm)
3 Week weight, g Survivors'1 Hemoglobin concentration, mg% Hematocrit
0
300
500
700
900
1100
472.0 b 16 7.89 c 30.0
404.6 C 15 7.39 c 30.5
297.9 d 12 7.38 c 30.3
204.6 e 13 7.36 c 30.9
117.9 f 8 7.05bc 30.0
80.4 f 8.57 5 6.07 b .27 27.1 .97
b
b
Tissue Muscle Heart Liver Bone Kidney
SE*
MgN i/g wet tissue .14 .14 b .10 b .10 b .13b
.26 .31bc .36 b .97bc 4.23 c
44b c .5ic .69 c 1.88 c 7.65 d
.60 c .80 d .99 d 3.75 d 9.73 e
1.52 d 1.39 e 2.04 e 4.93de 11.15 f
2.62 e 1.50e 1.43 f 5.91 e 11.48 f
.07 .05 .06 .30 .02
Standard error of pooled means, four samples per treatment. g Within each row, those values not followed by the same letter are significantly different at the 5% probability level. Originally 16 birds per treatment.
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015
to young chicks are presented in Table 1. Nickel in quantities of 300 mg/kg of diet and greater significantly reduced growth rate. The diets containing 900 and 1100 mg/kg nickel also proved to be quite toxic. Of the tissues studied, the kidney proved to be the most sensitive tissue with respect to nickel accumulation. Even at the 300 mg/kg level there were substantial increases in the nickel content of the tissue. Kidney nickel content tended to plateau at the higher dietary levels when other tissues started to show substantial amounts of nickel accumulation. Based upon the results obtained in Experiment 1, the level of 500 mg/kg was selected for the study of possible interactions in Experiment 2. These results are presented in Table 2. Cobalt, zinc, copper, and iron (100 mg/kg) were tested for their ability to alleviate nickel toxicity. The addition of copper, zinc, and iron did not alleviate the growth depression caused by nickel toxicity. Iron, copper, and zinc did not produce a consistent affect on the deposition of nickel tissues. However, there were significant changes in the nickel content of certain tissues associated with the feeding of these elements. The addition of cobalt to the nickel containing diet resulted in a further depression in growth rate and blood hemoglobin concentration. The nickel content of the kidney was also significantly increased by the
cobalt, 500 mg/kg nickel alone and with addition of 50, 100, 200 mg/kg cobalt. All birds were weighed and examined physically at weekly intervals. At 3 weeks of age, the chicks were killed and autopsied. Immediately prior to this, blood samples were taken by cardiac puncture from four randomly selected birds from each treatment replicate. Microhematocrit and hemoglobin determinations (by the method of Van Kampen and Zijlstra, 1961) were performed within 24 hr of collection. Specimens of liver, kidney, breast muscle, and leg bone were collected from the same eight chicks. Tissue samples were pooled and stored at —65 C prior to nickel analysis. The nickel content of these samples was determined in quadruplicate by the method of Nomoto and Sunderman (1970). The samples were initially digested with a mixture of nitric and sulfuric acid (5:1) followed by the addition of a mixture of nitric, sulfuric, and perchloric acids (10:2:1). Recovery data were obtained for each tissue analyzed. Average recovery was 95% (range 85 to 103). All results were examined by analysis of variance, and statistically significant differences among treatments were determined by the Q method described by Snedecor and Cochran (1967).
NICKEL TOXICITY AND METABOLISM
593
TABLE 2. Effect of cation additions to a nickel toxic diet on tissue nickel levels, body weights, hemoglobin concentrations, and hematocrit values Level of nickel and cation supplianentation (ppm)
3 Week weight, g Survivors" Hemoglobin concentration, mg% Hematocrit
0
500Ni
500Ni + 100CO
500Ni + lOOZn
500Ni + lOOCu
500Ni + lOOFe
397.ld 16 7.77 c 31.6
248.1 c 15 7.10 c 30.5
131.7 b 13 5.46 b 28.7
230.2 C 14 6.98 c 31.8
257.4 C 14 6.88 c 30.2
271.4 C 16 7.55 c 33.3
12.17
.12t> .13b .10b .13b
d
.51d .35 d .45C 7.03 c
.03 .02 .07 .01
.30 1.02
Mg Ni/g wet tissue
Muscle Heart Liver Kidney
.51 .52 e .72«i 7.93 e
.59 d .43d 1.01 d 10.80 f
.36 c .57 e .88 d 12.588
.48cd .26 c .55 c 7.73 d
Standard error of pooled means, four samples per treatment. ^Within each row, those values not followed by the same letter are significantly different at the 5% probability level. Originally 16 birds per treatment.
cobalt treatment. These results suggested that cobalt enhanced nickel toxicity. Experiment 3 was designed to study the possible cobalt-nickel interaction in more detail. Results are presented in Table 3. In this experiment, levels of cobalt of 50, 100, and 200 mg/kg were fed alone and in combination with 500 mg/kg of nickel. Feeding 100 and 200 mg of cobalt to chicks resulted in significant depressions in growth rate. Further decreases in growth rate were observed when cobalt was added to diets containing nickel. As was observed in the previous experiment, two of the three cobalt treatments did result in increases in the nickel content of the kidneys from chicks fed 500 mg/kg of nickel. However, there was no consistent effect of the cobalt treatments on the nickel content of the liver. The effect of cobalt on tissue nickel concentration does not appear to be of sufficient consistency or magnitude to account for the growth depressing effects of this element above or in the presence of nickel. Thus, it appears that both cobalt and nickel are toxic and that the effects are additive.
DISCUSSION A significant depression in body used as the primary criterion for nickel toxicity. And 300 mg/kg nickel chloride, produced this
weight was a state of nickel, as depression
when compared to the control birds. Weber and Reid (1968) found a significant growth reduction at 700 mg/kg nickel and above. The variance may be largely due to the fact that they used a non-purified diet. Other contributors might be the nickel salt (sulphate or acetate) and the breed of chicks used. Certainly, the present study produced markedly greater growth reduction, for at 500 mg/kg nickel the chicks weighed 57% less than the controls, whereas the equivalent figure from the data of Weber and Reid was 19%. Concurrent with the highly toxic (especially 900 and 1100 ppm) levels was a high rate of mortality, although the actual causes of death were not determined. The survivors in these treatments appeared to be normal in every respect except for their diminuitive size and juvenile appearance. No specific symptoms of any nutrient deficiency were observed, and therefore, it seemed that nickel toxicity did not precipitate any deficiencies. O'Dell et al. (1970) also considered nickel toxic calves to resemble younger animals in appearance and put forward the possibility of a relationship between nickel and growth hormones. Labella et al. (1973) reported that prolactin secretion was inhibited by high tissue concentrations of nickel. As expected when dietary nickel increased, so did tissue nickel. Bone and kidney accumulated the greater amounts, especially the latter
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015
Tissue
SE a
.10° .14°
.ll .15b
b
373.8 f 15 7.53 c 30.1
430.6 f 16 6.93bc 30.6
,12 .15b
.lib .13b
166.2 b c 15 6.60bc 24.6 Mg Ni/g
258.7 d e 15 7.03bc 28.9
b
200Co
lOOCo
.68 c 7.43 d
wet tissue
283.2^ 15 8.35C 29.7
500Ni
.84 c d 7.95 e
202.3cd 10 7.82bc 28.2
500Ni + 50Co
^Originally 16 birds per treatment.
Standard error of pooled means, four samples per treatment, b-f, Within each row, those values not followed by the same letter are significantly different at the 5% probability level.
Liver Kidney
Tissue
3 Week weight, g Survivors? Hemoglobin concentration, mg% Hematocrit
50Co
0
Level of nickel and cobalt supplementation (ppm)
TABLE 3. Effect of cobalt additions to a nickel toxic diet on tissue nickel levels, body weights, hemoglobin concentrations, and hematocrit values
ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015 .99d 8.78 f
128.8 b c 14 6.42b 24.0
500Ni + lOOCo
.75 c 6.67 c
96.3b 10 4.90 b 23.1
500Ni + 200Co
.05 .05
.60 1.08
17.96
SEa
X
> n
Z D r en
r Z >
NO
NICKEL TOXICITY AND METABOLISM
(Schnegg and Kirchgessner, 1975b). Further studies by Schnegg and Kirchgessner (1976a) led to the conclusion that iron absorption was inhibited during nickel deficiency. These investigators (Schnegg and Kirchgessner, 1976b) have also suggested an interaction of nickel with copper and zinc. This conclusion is based upon the observation that nickel deficiency was associated with decreased levels of iron, copper, and zinc in the liver, spleen, and kidneys. Thus, nickel does interact with other elements at low dietary concentrations, although these elements had no effect on the course of nickel toxicity in the studies reported here.
REFERENCES Labella, F. S., R. Dular, P. Lemon, and G. Queen, 1973. Prolactin secretion-inhibition by nickel. Nature 245:3 3 0 - 3 32. Leach, R. M., Jr., and M. C. Nesheim, 1965. Nutritional, genetic and morphological studies of an abnormal cartilage formation in young chicks. J. Nutr. 86:230-244. Nielsen, F. H., and D. A. Ollerich, 1974. Nickel: A new essential trace element. Fed. Proc. 33:1767-1774. Nomoto, S., and F. W. Sunderman, Jr., 1970. Atomic absorptive spectrometry of nickel in serum, urine and other biological materials. Clin. Chem. 16:477-485. O'Dell, G. D., W. J. Miller, W. A. King, S. L. Moore, and D. M. Blockman, 1970. Nickel toxicity in the young bovine. J. Nutr. 100:1444—1453. Phatak, S. S., and V. N. Patwardhan, 1950. Toxicity of nickel. J. Sci. Ind. Res. 9b:70-76. Phatak, S. S., and V. N. Patwardhan, 1952. Toxicity of nickel: accumulation of nickel in rats on nickelcontaining diets and its elimination. J. Sci. Ind, Res. l l b : 1 7 3 - 1 7 6 . Schnegg, A., and M. Kirchgessner, 1975a. Essentiality of nickel for the growth of animals. Z. Tierphysiol. Tierern'ah. Futtermittelkiende 36:63-74. Schnegg, A., and M. Kirchgessner, 1975b. Changes in the homoglobin content, erythrocyte content and hematocrit in nickel deficiency. Nutr. Metab. 19:268-278. Schnegg, A., and M. Kirchgessner, 1976a. Absorption and metabolic efficiency of iron during nickel deficiency. Int. J. Vitamin Nutr. Res. 46:96—99. Schnegg, A., and M. Kirchgessner, 1976b. Interaction of nickel with iron, copper and zinc. Archiv. fur Tierenahrung 26:543 — 549. Snedecor, G. W., and W. G. Cochran, 1967. Page 2 7 2 - 2 7 3 . Statistical methods. 6th ed. The Iowa State University Press, Ames, IA. Spears, J. W., E. E. Hatfield, and R. M. Forbes, 1977. Nickel-copper interrelationship in the rat. Proc. Soc. Exp. Biol. Med. 156:140-143. Sunderman, F. W., Jr., 1977. A review of the metabolism and toxiology of nickel. Ann. Clin. Lab. Sci. 7:377-398.
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organ. This is in concert with other studies on nickel distribution and the observation that nickel is excreted in the urine (Sunderman, 1977). As little as 300 mg/kg resulted in a significant rise in kidney nickel content. However, the dramatic increases in kidney nickel appeared to plateau at about 900 mg/kg dietary level, as if this organ were reaching a saturation peak. Simultaneous with this was a large increase in muscle nickel content together with a continuous rise in bone nickel concentration. It may be that at this level, around 1000 mg/kg nickel, the urinary excretion mechanism is overloaded and cannot cope with increased absorption of dietary nickel. The result could be influx into all other body tissues, especially muscle, where a small concentration increase represents a large absolute increase. The cations (Co, Cu, Zn, Fe) used in an attempt to counteract nickel toxicity were chosen with reference to the periodic table, thereby increasing the likelihood of an interaction between chemically similar elements. The addition of 100 mg/kg of these elements produced no well defined patterns. Although these elements did result in some changes in tissue nickel content, none of these elements produced a consistent pattern which would be indicative of an interaction between one of these elements and nickel. Furthermore, none of the other criteria measured suggested that there was an interaction between these elements and nickel. The growth depression observed with addition of cobalt appears to be due to the toxicity of cobalt independent of an effect upon nickel toxicity. The toxicity of cobalt and nickel appeared to be additive. Thus, it is concluded that the effects of nickel toxicity are not due to an effect of this element on the metabolism of cobalt, copper, iron, or zinc. First of all, dietary additions of these elements did not reverse the course of nickel toxicity. Secondly, the symptoms of nickel toxicity did not resemble deficiency symptoms characteristic for these elements. These results are in contrast to recent observations made at low dietary concentrations of nickel. Spears et al. (1977) found that nickel supplementation to a copper deficient diet resulted in increased weight gain and blood hematocrits. This response to nickel was observed only with the copper deficient diet and not with diets containing adequate amounts of copper. It also has been reported that nickel deficiency results in anemia
595
596
LING AND LEACH
Van Kampen, E. J., and W. G. Zijlstra, 1961. Standardization of hemoglobinometry. II. The hemiglobinezamide method. Clin. Chem. Acta 6:538-544.
Weber, C. W., and B. L. Reid, 1968. Nickel toxicity in growing chicks. J. Nutr. 95:612—616. Weber, C. W., and B. L. Ried, 1969. Nickel toxicity in young growing mice. J. Anim. Sci. 28:620—623.
Downloaded from http://ps.oxfordjournals.org/ at National Institute of Education Library, Serials Unit on May 25, 2015