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Kidney Arginase Activity in Chicks Fed Diets Containing Deficient or Excessive Concentrations of Lysine, Arginine, Histidine, or Total Nitrogen
Kidney Arginase Activity in Chicks Fed Diets Containing Deficient or Excessive Concentrations of Lysine, Arginine, Histidine, or Total Nitrogen KELLY R. ROBBINS Department of Animal Science, University of Tennessee, Knoxville, Tennessee 37901 DAVID H. BAKER Department of Animal Science, University of Illinois, Urbana, Illinois 61801 (Received for publication August 7, 1980)
1981 Poultry Science 60:829-834 INTRODUCTION
In vivo amino acid catabolism is regulated by the level of the rate-limiting catabolic enzyme and by changes in substrate concentration. However, the relative importance of these two controlling mechanisms varies with the amino acid in question and the nutritive status of the animal. It appears, for example, that catabolism of lysine (Wang et ai, 1973) and histidine (Kang-Lee and Harper, 1977, 1979) is regulated by their tissue concentrations at low dietary levels, despite the activity of their respective catabolic enzymes. Only at excessive intakes does the oxidation of histidine and lysine appear to be regulated by enzyme level. However, Chu and Nesheim (1979) demonstrated the kidney arginase plays a major role in regulation of avian arginine metabolism even at low plasma arginine concentrations. Because of this, the chick's arginine requirement can be increased markedly by feeding an excess of any one of a variety of single amino acids which increases kidney arginase activity (Anderson and Dobson, 1959; Austic and Nesheim, 1970). The most effective amino acid is lysine. Allen and Baker (1972), for example, estimated that a 1% dietary excess of lysine results in a 50% increase in the chick's arginine requirement.
Another feature of the lysine-arginine relationship is that plasma lysine concentration is markedly increased in chicks fed argininedeficient diets (Stutz et al., 1972; Zimmerman and Scott, 1965). In fact, in the study by Zimmerman and Scott (1965), a 40% reduction in dietary arginine resulted in plasma lysine concentrations equal to that achieved by feeding a 40% excess of lysine in an arginineadequate diet. Hence, it seems plausible that under conditions of arginine deficiency, kidney arginase activity may increase in a manner similar to that achieved when excess lysine is fed. If so, this may in turn result in less efficient utilization of arginine when fed at levels below its requirement. The present studies were undertaken to more clearly define the effects of certain amino acid deficiencies or excesses on kidney arginase activity. To facilitate the studies, purified crystalline amino acid diets were used.
EXPERIMENTAL PROCEDURE
Except for slight excesses of sulfur amino acids, tryptophan and threonine, the basal diet (Table 1) was formulated to contain 100% of the requirements for each amino acid. In each experiment, dietary levels of L-arginine-HCl, 829
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
ABSTRA CT Three experiments were conducted with 1 to 2-week-old chicks fed purified crystalline amino acid diets. Kidney arginase activity increased substantially when total dietary nitrogen exceeded the dietary requirement for maximal chick weight gain. Single deficiencies of either histidine or lysine in nitrogen-adequate diets also resulted in marked increases in enzyme level. Arginine deficiency resulted in a slight increase in arginase activity, but the magnitude of the increase appeared to have little effect on efficiency of arginine utilization. Further, the response could be prevented by making lysine and arginine equally limiting. Increasing the lysine:arginine ratio to two in a nitrogen-deficient diet did not increase arginase activity. The same ratio in an arginine- and nitrogen-adequate diet resulted in a twofold increase in arginase activity accompanied by reductions in rate and efficiency of weight gain. (Key words: amino acids, lysine, arginine, histidine, kidney arginase)
830
ROBBINS AND BAKER TABLE 1. Composition of the purified crystalline amino acid basal diet
Ingredient
59.75 20.48
10.00 5.37 3.00 1.00 .20 .20
100.00
Amino acid mix
(%)
L-arginine-HCl L-lysine-HCl L-histidine-HCl-H 2 0 L-tyrosine L-tryptophan L-phenylalanine DL-methionine L-cystine L-threonine L-leucine L-isoleucine L-valine Glycine L-proline L-glutamic acid
1.15 1.14 .45 .45 .15 .50 .35 .35 .65 1.00 .60 .69 .60 .40 12.00 20.48
Baker et al. (1979).
L-lysine-HCl, L-histidine-HCl'H 2 0 and/or the entire amino acid mixture were varied to provide experimental diets of varying amino acid adequacy. In each diet, appropriate adjustments were made in the level of cornstarch. Male New Hampshire x Columbian chicks were employed in Experiment 1 (completed at the University of Illinois). In Experiments 2 and 3 (completed at the University of Tennessee) male Hubbard chicks were used. Chicks were fed a corn-soybean meal diet for the first 7 days posthatching. Following an overnight fast, they were selected and fed the experimental diets starting on day 8 posthatching. Experimental groups were selected to have the same initial mean weight and a similar weight distribution. Each experimental diet was fed to triplicate groups of 7 chicks for Experiment 1, and to triplicate groups of 6 chicks in Experiments 2 and 3. The experimental diets were fed during days 8 to 16 posthatching in Experiment 1 and during days 8 to 15 posthatching in Experiments 2 and 3. Chicks were housed in electrically-heated chick batteries in continuous light and kept at 27 to 30 C. Feed and water were supplied ad libitum. At the termination of Experiment 1, one replicate group from each treatment was selected on the basis of closeness of average final body weight to the treatment mean. Each chick from the selected lot was killed and sample of kidney obtained. Upon terminating Experiments 2 and 3, kidney samples were
obtained from 2 randomly selected chicks per replicate group (i.e., 6 chicks per treatment). Kidney arginase activity was measured in homogenates as described by Smith and Lewis (1963). Analysis of variance and appropriate single degree-of-freedom comparisons were used to assess treatment effects. Kidney arginase activities were heterogeneous as to error variance. Since a transformation to natural logs resulted in homogeneous variances, statistical analyses were done on log transformed data. RESULTS Experiment 1. As the level of the balanced amino acid mixture increased from subadequate to superadequate levels, kidney arginase activity increased markedly (Fig. 1). The greatest increase, however, occurred when total nitrogen was in excess of that required for maximal growth (Fig. 1 and Table 2). When dietary nitrogen was present at 100% of its requirement, reduction of dietary arginine to 50% of its requirement resulted in a slight increase in kidney arginase activity (Fig. 1), but the increase was not significant (P>.05). However, deficiencies of either histidine or lysine significantly (P<.05) increased arginase activity. The observed growth depression (Table 2) was equally severe when the dietary concentration of either arginine, lysine, or histidine was deficient.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
Cornstarch Amino acid mix Corn oil Salt mixture 3 Cellulose NaHC0 3 Choline chloride Vitamins* a-Tocopheryl acetate (20mg/kg) Ethoxyquin (125 mg/kg)
(%)
CHICK KIDNEY ARGINASE ACTIVITY
831
DISCUSSION
LIMITING
AMINO
ACID
FIG. 1. Kidney arginase activities of chicks fed diets containing graded levels of total nitrogen ( t o p graph) or single deficiencies of arginine, histidine, and lysine in a nitrogen-adequate diet ( b o t t o m graph). Data are means of seven kidney samples per t r e a t m e n t . The pooled SEM for the log transformed data was .072.
Experiment 2. Kidney arginase activity increased when either lysine or arginine was reduced to 50% of its requirement in the nitrogen-adequate diet (Table 3). However, when lysine and arginine were simultaneously deficient, arginase activity was unaffected. As a result, the lysine x arginine interaction was significant (P<.05). Gain and gain/feed of chicks fed the three amino acid-deficient diets did not differ significantly (P>.05) from one another. Experiment 3. As in Experiment 1, kidney
As dietary nitrogen was increased in Experiment 1, kidney arginase activity increased markedly. The greatest increases, however, occurred at nitrogen levels in excess of the requirement. Plasma amino acids would accumulate rapidly under such conditions; therefore, the increase in arginase activity probably represents the sum effect of all those amino acids capable of inducing the enzyme (Austic and Nesheim, 1970). It was our hypothesis that an arginine deficiency would also result in a marked increase in arginase activity due to high plasma concentrations of lysine which result (Zimmerman and Scott, 1965). We did not, however, expect lysine or histidine deficiency to have the same effect, because such deficiencies appeared not to increase plasma concentrations of amino acids that induce arginase (Ohno and Tasaki, 1972; Zimmerman and Scott, 1965). In fact, when deficient levels of lysine were fed, threonine accumulated in the plasma (Zimmerman and Scott, 1965), and this amino acid has been shown to inhibit arginase activity (Austic and Nesheim, 1970). However, in Experiment 1 quite the opposite occurred. An arginine deficiency resulted in only a slight increase, whereas a deficiency of either histidine or lysine resulted in a three to fourfold increase in kidney arginase activity. Chicks fed the diets deficient in histidine or lysine were necessarily consuming relative excesses of all other amino acids including arginine. Hence, it appears that consumption of excess arginine per se was the primary cause of increased arginase activity. Chicks fed the basal
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
arginase activity increased proportionately with increasing levels of dietary nitrogen (Table 4). When arginine concentration was doubled in diets containing either 50% or 100% of the nitrogen requirement, kidney arginase activity increased twofold. With dietary nitrogen at 50% of its requirement, neither excess lysine nor excess histidine significantly (P>.05) affected arginase activity. In diets containing 100% of the nitrogen requirement, kidney arginase activity was significantly (P<.05) increased when lysine concentration was doubled, but was unaffected by excess histidine. The significant (P<.05) depression in gain and gain/feed observed when excess lysine was fed is typical of the lysine-arginine antagonism.
832
ROBBINS AND BAKER
TABLE 2. Effect of dietary nitrogen level and amino acid balance on chick performance (Experiment Dietary nitrogen (% of requirement)
Deficient amino acid
50 100 150 200 100 100 100
Arginine Lysine Histidine Pooled SEM
l)a
Gain (g) c
Gain/feed 0
67 123 118 99
.407 .690 .780 .711 .400 .417 .367 .019
43 43 39 3.9
The effect of amino acid deficiency was significant (P<.05).
diet and arginine-deficient diet consumed an average of 12 mg arginine per gram gain; those fed the histidine- and lysine-deficient diets consumed an average of 22 mg arginine per gram gain. These ratios correlated well with the observed differences in arginase activity. Although arginase activity was increased slightly when chicks were fed the argininedeficient diet in Experiment 1, the increase was not statistically significant. Thus, we reevaluated this response in Experiment 2. In this experiment, both lysine and arginine deficiencies resulted in increased arginase activity. However, as in the previous experiment, the response was larger when chicks were
fed the lysine-deficient diet. These results further demonstrate that the effect of arginine deficiency was clearly a result of an imbalance between arginine and lysine, since, when lysine and arginine were equally limiting, arginase activity remained low. When lysine was made equally limiting in the arginine-deficient diet, chick performance was not significantly improved. Thus, it appears that the increase in arginase activity in chicks fed the argininedeficient diet was not enough to lower efficiency of arginine utilization. The failure of arginine deficiency to increase arginase activities to levels achieved by the addition of a proportionate amount of excess
TABLE 3. Effect of lysine and arginine deficiency on chick performance and kidney arginase activity (Experiment 2)
Deficient amino acids a
Gain (g) b,c
Gain/feed ' c
Kidney arginase activity ' e (mmoles urea/g wet tissue/hr)
None Lysine Arginine Lysine and arginine
156 56 57 63
.692 .425 .430 .444
3.72 6.35 5.02 3.67
Arginine and/or lysine were reduced to one-half the concentration in the basal diet (Table 1). Mean of three groups of 6 chicks each fed the experimental diets from day 8 to day 15 posthatching. Average initial weight was 98 g. Pooled SEM for gain and gain/feed were 4.2 and .016, respectively. The main effect of amino acid deficiency was significant (P<.05). Mean of six kidney samples obtained from 2 chicks from each of the three replicate groups. Pooled SEM of the log transformed data was . 180. The lysine X arginine interaction was significant (P<.05).
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
Mean of three groups of 7 chicks each fed the experimental diets from day 8 to 16 days posthatching. Average initial weight was 91 g. b„Either arginine, lysine, or histidine was reduced to one-half the concentration in the basal diet (Table 1).
None Arginine Lysine Histidine None Arginine Lysine Histidine None
Amino acid
200 200 200
100 100 100
(% of requirement)
Excess amino acid
73 65 63 76 149 149 112 143 121
Gain (g) a ' b .380 .364 .376 .386 .654 .740 .577 .705 .760
Gain
The linear effect of dietary nitrogen was significant (P<,05). Excess arginine significantly (P<.05) increased argi 100% dietary nitrogen, excess lysine significantly (P<.05) increased arginase activity.
Mean of six kidney samples obtained from 2 chicks from each of the three replicate groups. Pooled SEM of the log
The linear effect of dietary nitrogen was significant ,(P<.01). At 100% dietary nitrogen, excess lysine significantly (
Mean of three groups of 6 chicks each fed the experimental diets from day 8 to day 15 posthatching. Average gain/feed were 5.3 and .017, respectively.
200
100 100 100
100
50 50 50
50
(% of
requiremerj it)
Dietai y nitrogen
TABLE 4. Effect of dietary nitrogen level and amino acid balance on chick performance and kidney
m http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
ROBBINS AND BAKER
834
REFERENCES Allen, N. K., and D. H. Baker, 1972. Effect of excess lysine on the utilization of and requirement for arginine by the chick. Poultry Sci. 51:902—906. Anderson, J. O., and D. C. Dobson, 1959. Amino acid requirements of the chick. 2. Effect of total essential amino acid level in the diet on the arginine and lysine requirement. Poultry Sci. 38:1140-1150. Austic, R. E., and M. C. Nesheim, 1970. Role of kidney arginase in variations of the arginine
requirement of chicks. J. Nutr. 100:855—868. Baker, D. H., K. R. Robbins, and J. S. Buck, 1979. Modification of the level of histidine and sodium bicarbonate in the Illinois crystalline amino acid diet. Poultry Sci. 58:749-750. Chu, S. H., and M. C. Nesheim, 1979. The relationship of plasma arginine and kidney arginase activity to arginine degradation in chickens. J. Nutr. 109:1752-1758. Kang-Lee, Y. A., and A. E. Harper, 1977. Effect of histidine intake and hepatic histidase activity on the metabolism of histidine in vivo. J. Nutr. 107:1427-1443. Kang-Lee, Y. A., and A. E. Harper, 1979. Effect of induction of histidase on histidine metabolism in vivo. J. Nutr. 109:291-299. Ohno, T., and I. Tasaki, 1972. Effect of dietary lysine level on plasma free amino acids in adult cockerels. J. Nutr. 102:603-608. Smith, G. H., and D. Lewis, 1963. Arginine in poultry nutrition. Brit. J. Nutr. 17:433—444. Stutz, M. W., J. E. Savage, and B. L. O'Dell, 1972. Cation-anion balance in relation to arginine metabolism in the chick. J. Nutr. 102:449—458. Wang, S. H., L. O. Crosby, and M. C. Nesheim, 1973. Effect of dietary excesses of lysine and arginine on the degradation of lysine by chicks. J. Nutr. 103:384-391. Zimmerman, R. A., and H. M. Scott, 1965. Interrelationship of plasma amino acid levels and weight gain in the chick as influenced by suboptimal and superoptimal dietary concentrations of single amino acids. J. Nutr. 87:13—18.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
lysine to arginine-adequate diets is apparently the result of reduced nitrogen consumption despite the fact that total body size is reduced proportionately. This is well illustrated by the results of Experiment 3. When excess lysine was added to a diet containing only 50% of the nitrogen requirement, kidney arginase activity was not significantly increased, and chick performance was not affected. However, the same lysine:arginine ratio in nitrogen-adequate diets resulted in markedly increased kidney arginase activity and reduced gain and gain/feed characteristic of the lysine-arginine antagonism. The magnitude of the kidney arginase response to dietary excesses of arginine was equally dependent upon the dietary nitrogen level.
1981 Poultry Science 60:829-834 INTRODUCTION
In vivo amino acid catabolism is regulated by the level of the rate-limiting catabolic enzyme and by changes in substrate concentration. However, the relative importance of these two controlling mechanisms varies with the amino acid in question and the nutritive status of the animal. It appears, for example, that catabolism of lysine (Wang et ai, 1973) and histidine (Kang-Lee and Harper, 1977, 1979) is regulated by their tissue concentrations at low dietary levels, despite the activity of their respective catabolic enzymes. Only at excessive intakes does the oxidation of histidine and lysine appear to be regulated by enzyme level. However, Chu and Nesheim (1979) demonstrated the kidney arginase plays a major role in regulation of avian arginine metabolism even at low plasma arginine concentrations. Because of this, the chick's arginine requirement can be increased markedly by feeding an excess of any one of a variety of single amino acids which increases kidney arginase activity (Anderson and Dobson, 1959; Austic and Nesheim, 1970). The most effective amino acid is lysine. Allen and Baker (1972), for example, estimated that a 1% dietary excess of lysine results in a 50% increase in the chick's arginine requirement.
Another feature of the lysine-arginine relationship is that plasma lysine concentration is markedly increased in chicks fed argininedeficient diets (Stutz et al., 1972; Zimmerman and Scott, 1965). In fact, in the study by Zimmerman and Scott (1965), a 40% reduction in dietary arginine resulted in plasma lysine concentrations equal to that achieved by feeding a 40% excess of lysine in an arginineadequate diet. Hence, it seems plausible that under conditions of arginine deficiency, kidney arginase activity may increase in a manner similar to that achieved when excess lysine is fed. If so, this may in turn result in less efficient utilization of arginine when fed at levels below its requirement. The present studies were undertaken to more clearly define the effects of certain amino acid deficiencies or excesses on kidney arginase activity. To facilitate the studies, purified crystalline amino acid diets were used.
EXPERIMENTAL PROCEDURE
Except for slight excesses of sulfur amino acids, tryptophan and threonine, the basal diet (Table 1) was formulated to contain 100% of the requirements for each amino acid. In each experiment, dietary levels of L-arginine-HCl, 829
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
ABSTRA CT Three experiments were conducted with 1 to 2-week-old chicks fed purified crystalline amino acid diets. Kidney arginase activity increased substantially when total dietary nitrogen exceeded the dietary requirement for maximal chick weight gain. Single deficiencies of either histidine or lysine in nitrogen-adequate diets also resulted in marked increases in enzyme level. Arginine deficiency resulted in a slight increase in arginase activity, but the magnitude of the increase appeared to have little effect on efficiency of arginine utilization. Further, the response could be prevented by making lysine and arginine equally limiting. Increasing the lysine:arginine ratio to two in a nitrogen-deficient diet did not increase arginase activity. The same ratio in an arginine- and nitrogen-adequate diet resulted in a twofold increase in arginase activity accompanied by reductions in rate and efficiency of weight gain. (Key words: amino acids, lysine, arginine, histidine, kidney arginase)
830
ROBBINS AND BAKER TABLE 1. Composition of the purified crystalline amino acid basal diet
Ingredient
59.75 20.48
10.00 5.37 3.00 1.00 .20 .20
100.00
Amino acid mix
(%)
L-arginine-HCl L-lysine-HCl L-histidine-HCl-H 2 0 L-tyrosine L-tryptophan L-phenylalanine DL-methionine L-cystine L-threonine L-leucine L-isoleucine L-valine Glycine L-proline L-glutamic acid
1.15 1.14 .45 .45 .15 .50 .35 .35 .65 1.00 .60 .69 .60 .40 12.00 20.48
Baker et al. (1979).
L-lysine-HCl, L-histidine-HCl'H 2 0 and/or the entire amino acid mixture were varied to provide experimental diets of varying amino acid adequacy. In each diet, appropriate adjustments were made in the level of cornstarch. Male New Hampshire x Columbian chicks were employed in Experiment 1 (completed at the University of Illinois). In Experiments 2 and 3 (completed at the University of Tennessee) male Hubbard chicks were used. Chicks were fed a corn-soybean meal diet for the first 7 days posthatching. Following an overnight fast, they were selected and fed the experimental diets starting on day 8 posthatching. Experimental groups were selected to have the same initial mean weight and a similar weight distribution. Each experimental diet was fed to triplicate groups of 7 chicks for Experiment 1, and to triplicate groups of 6 chicks in Experiments 2 and 3. The experimental diets were fed during days 8 to 16 posthatching in Experiment 1 and during days 8 to 15 posthatching in Experiments 2 and 3. Chicks were housed in electrically-heated chick batteries in continuous light and kept at 27 to 30 C. Feed and water were supplied ad libitum. At the termination of Experiment 1, one replicate group from each treatment was selected on the basis of closeness of average final body weight to the treatment mean. Each chick from the selected lot was killed and sample of kidney obtained. Upon terminating Experiments 2 and 3, kidney samples were
obtained from 2 randomly selected chicks per replicate group (i.e., 6 chicks per treatment). Kidney arginase activity was measured in homogenates as described by Smith and Lewis (1963). Analysis of variance and appropriate single degree-of-freedom comparisons were used to assess treatment effects. Kidney arginase activities were heterogeneous as to error variance. Since a transformation to natural logs resulted in homogeneous variances, statistical analyses were done on log transformed data. RESULTS Experiment 1. As the level of the balanced amino acid mixture increased from subadequate to superadequate levels, kidney arginase activity increased markedly (Fig. 1). The greatest increase, however, occurred when total nitrogen was in excess of that required for maximal growth (Fig. 1 and Table 2). When dietary nitrogen was present at 100% of its requirement, reduction of dietary arginine to 50% of its requirement resulted in a slight increase in kidney arginase activity (Fig. 1), but the increase was not significant (P>.05). However, deficiencies of either histidine or lysine significantly (P<.05) increased arginase activity. The observed growth depression (Table 2) was equally severe when the dietary concentration of either arginine, lysine, or histidine was deficient.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
Cornstarch Amino acid mix Corn oil Salt mixture 3 Cellulose NaHC0 3 Choline chloride Vitamins* a-Tocopheryl acetate (20mg/kg) Ethoxyquin (125 mg/kg)
(%)
CHICK KIDNEY ARGINASE ACTIVITY
831
DISCUSSION
LIMITING
AMINO
ACID
FIG. 1. Kidney arginase activities of chicks fed diets containing graded levels of total nitrogen ( t o p graph) or single deficiencies of arginine, histidine, and lysine in a nitrogen-adequate diet ( b o t t o m graph). Data are means of seven kidney samples per t r e a t m e n t . The pooled SEM for the log transformed data was .072.
Experiment 2. Kidney arginase activity increased when either lysine or arginine was reduced to 50% of its requirement in the nitrogen-adequate diet (Table 3). However, when lysine and arginine were simultaneously deficient, arginase activity was unaffected. As a result, the lysine x arginine interaction was significant (P<.05). Gain and gain/feed of chicks fed the three amino acid-deficient diets did not differ significantly (P>.05) from one another. Experiment 3. As in Experiment 1, kidney
As dietary nitrogen was increased in Experiment 1, kidney arginase activity increased markedly. The greatest increases, however, occurred at nitrogen levels in excess of the requirement. Plasma amino acids would accumulate rapidly under such conditions; therefore, the increase in arginase activity probably represents the sum effect of all those amino acids capable of inducing the enzyme (Austic and Nesheim, 1970). It was our hypothesis that an arginine deficiency would also result in a marked increase in arginase activity due to high plasma concentrations of lysine which result (Zimmerman and Scott, 1965). We did not, however, expect lysine or histidine deficiency to have the same effect, because such deficiencies appeared not to increase plasma concentrations of amino acids that induce arginase (Ohno and Tasaki, 1972; Zimmerman and Scott, 1965). In fact, when deficient levels of lysine were fed, threonine accumulated in the plasma (Zimmerman and Scott, 1965), and this amino acid has been shown to inhibit arginase activity (Austic and Nesheim, 1970). However, in Experiment 1 quite the opposite occurred. An arginine deficiency resulted in only a slight increase, whereas a deficiency of either histidine or lysine resulted in a three to fourfold increase in kidney arginase activity. Chicks fed the diets deficient in histidine or lysine were necessarily consuming relative excesses of all other amino acids including arginine. Hence, it appears that consumption of excess arginine per se was the primary cause of increased arginase activity. Chicks fed the basal
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
arginase activity increased proportionately with increasing levels of dietary nitrogen (Table 4). When arginine concentration was doubled in diets containing either 50% or 100% of the nitrogen requirement, kidney arginase activity increased twofold. With dietary nitrogen at 50% of its requirement, neither excess lysine nor excess histidine significantly (P>.05) affected arginase activity. In diets containing 100% of the nitrogen requirement, kidney arginase activity was significantly (P<.05) increased when lysine concentration was doubled, but was unaffected by excess histidine. The significant (P<.05) depression in gain and gain/feed observed when excess lysine was fed is typical of the lysine-arginine antagonism.
832
ROBBINS AND BAKER
TABLE 2. Effect of dietary nitrogen level and amino acid balance on chick performance (Experiment Dietary nitrogen (% of requirement)
Deficient amino acid
50 100 150 200 100 100 100
Arginine Lysine Histidine Pooled SEM
l)a
Gain (g) c
Gain/feed 0
67 123 118 99
.407 .690 .780 .711 .400 .417 .367 .019
43 43 39 3.9
The effect of amino acid deficiency was significant (P<.05).
diet and arginine-deficient diet consumed an average of 12 mg arginine per gram gain; those fed the histidine- and lysine-deficient diets consumed an average of 22 mg arginine per gram gain. These ratios correlated well with the observed differences in arginase activity. Although arginase activity was increased slightly when chicks were fed the argininedeficient diet in Experiment 1, the increase was not statistically significant. Thus, we reevaluated this response in Experiment 2. In this experiment, both lysine and arginine deficiencies resulted in increased arginase activity. However, as in the previous experiment, the response was larger when chicks were
fed the lysine-deficient diet. These results further demonstrate that the effect of arginine deficiency was clearly a result of an imbalance between arginine and lysine, since, when lysine and arginine were equally limiting, arginase activity remained low. When lysine was made equally limiting in the arginine-deficient diet, chick performance was not significantly improved. Thus, it appears that the increase in arginase activity in chicks fed the argininedeficient diet was not enough to lower efficiency of arginine utilization. The failure of arginine deficiency to increase arginase activities to levels achieved by the addition of a proportionate amount of excess
TABLE 3. Effect of lysine and arginine deficiency on chick performance and kidney arginase activity (Experiment 2)
Deficient amino acids a
Gain (g) b,c
Gain/feed ' c
Kidney arginase activity ' e (mmoles urea/g wet tissue/hr)
None Lysine Arginine Lysine and arginine
156 56 57 63
.692 .425 .430 .444
3.72 6.35 5.02 3.67
Arginine and/or lysine were reduced to one-half the concentration in the basal diet (Table 1). Mean of three groups of 6 chicks each fed the experimental diets from day 8 to day 15 posthatching. Average initial weight was 98 g. Pooled SEM for gain and gain/feed were 4.2 and .016, respectively. The main effect of amino acid deficiency was significant (P<.05). Mean of six kidney samples obtained from 2 chicks from each of the three replicate groups. Pooled SEM of the log transformed data was . 180. The lysine X arginine interaction was significant (P<.05).
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
Mean of three groups of 7 chicks each fed the experimental diets from day 8 to 16 days posthatching. Average initial weight was 91 g. b„Either arginine, lysine, or histidine was reduced to one-half the concentration in the basal diet (Table 1).
None Arginine Lysine Histidine None Arginine Lysine Histidine None
Amino acid
200 200 200
100 100 100
(% of requirement)
Excess amino acid
73 65 63 76 149 149 112 143 121
Gain (g) a ' b .380 .364 .376 .386 .654 .740 .577 .705 .760
Gain
The linear effect of dietary nitrogen was significant (P<,05). Excess arginine significantly (P<.05) increased argi 100% dietary nitrogen, excess lysine significantly (P<.05) increased arginase activity.
Mean of six kidney samples obtained from 2 chicks from each of the three replicate groups. Pooled SEM of the log
The linear effect of dietary nitrogen was significant ,(P<.01). At 100% dietary nitrogen, excess lysine significantly (
Mean of three groups of 6 chicks each fed the experimental diets from day 8 to day 15 posthatching. Average gain/feed were 5.3 and .017, respectively.
200
100 100 100
100
50 50 50
50
(% of
requiremerj it)
Dietai y nitrogen
TABLE 4. Effect of dietary nitrogen level and amino acid balance on chick performance and kidney
m http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 8, 2016
ROBBINS AND BAKER
834
REFERENCES Allen, N. K., and D. H. Baker, 1972. Effect of excess lysine on the utilization of and requirement for arginine by the chick. Poultry Sci. 51:902—906. Anderson, J. O., and D. C. Dobson, 1959. Amino acid requirements of the chick. 2. Effect of total essential amino acid level in the diet on the arginine and lysine requirement. Poultry Sci. 38:1140-1150. Austic, R. E., and M. C. Nesheim, 1970. Role of kidney arginase in variations of the arginine
requirement of chicks. J. Nutr. 100:855—868. Baker, D. H., K. R. Robbins, and J. S. Buck, 1979. Modification of the level of histidine and sodium bicarbonate in the Illinois crystalline amino acid diet. Poultry Sci. 58:749-750. Chu, S. H., and M. C. Nesheim, 1979. The relationship of plasma arginine and kidney arginase activity to arginine degradation in chickens. J. Nutr. 109:1752-1758. Kang-Lee, Y. A., and A. E. Harper, 1977. Effect of histidine intake and hepatic histidase activity on the metabolism of histidine in vivo. J. Nutr. 107:1427-1443. Kang-Lee, Y. A., and A. E. Harper, 1979. Effect of induction of histidase on histidine metabolism in vivo. J. Nutr. 109:291-299. Ohno, T., and I. Tasaki, 1972. Effect of dietary lysine level on plasma free amino acids in adult cockerels. J. Nutr. 102:603-608. Smith, G. H., and D. Lewis, 1963. Arginine in poultry nutrition. Brit. J. Nutr. 17:433—444. Stutz, M. W., J. E. Savage, and B. L. O'Dell, 1972. Cation-anion balance in relation to arginine metabolism in the chick. J. Nutr. 102:449—458. Wang, S. H., L. O. Crosby, and M. C. Nesheim, 1973. Effect of dietary excesses of lysine and arginine on the degradation of lysine by chicks. J. Nutr. 103:384-391. Zimmerman, R. A., and H. M. Scott, 1965. Interrelationship of plasma amino acid levels and weight gain in the chick as influenced by suboptimal and superoptimal dietary concentrations of single amino acids. J. Nutr. 87:13—18.
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lysine to arginine-adequate diets is apparently the result of reduced nitrogen consumption despite the fact that total body size is reduced proportionately. This is well illustrated by the results of Experiment 3. When excess lysine was added to a diet containing only 50% of the nitrogen requirement, kidney arginase activity was not significantly increased, and chick performance was not affected. However, the same lysine:arginine ratio in nitrogen-adequate diets resulted in markedly increased kidney arginase activity and reduced gain and gain/feed characteristic of the lysine-arginine antagonism. The magnitude of the kidney arginase response to dietary excesses of arginine was equally dependent upon the dietary nitrogen level.