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Plasma 17-Hydroxycorticosteroid Levels in Healthy and Diarrhoeic Calves
Br. vet.]. (197 1), I27, 372
PLASMA 17-HYDROXYCORTICOSTEROID LEVELS IN HEALTHY AND DIARRHOEIC CALVES BY M. DvoR.A.
K
Veterinary Research Institute, Brno, Czechoslovakia
SUMMARY
Plasma free I 7-hydroxycorticosteroid (I 7-0HCS) levels of healthy calves of the red-spotted breed varied with age. The highest concentration was found in newborn calves during the first I6 hours of life. The I 7-0HCS values observed in diarrhoeic calves also varied with age. However, the I 7-0HCS concentration in diarrhoeic calves aged I- I4 days was significantly higher than that of healthy animals of the same age. INTRODUCTION
Adrenocortical activity, which plays an important role in the general adaptation syndrome (Selye, 1946), has not received much attention in calves. According to Balfour (I962 ) and Short (1962), calves develop quantitative and qualitative changes in corticosteroid secretion during postnatal life. Moll ( I 965) favours the view that calves are born with immature adrenals and are poorly equipped to cope with major environmental changes. Adrenal cortical insufficiency in calves .with prolonged intrauterine development was reported by Holm, Parker & Galligan (1961 ). Lindt (1962) described adrenal cortical insufficiency in calves with colisepticaemia associated with adrenal haemorrhages. References to glucocorticoid levels in blood plasma of adult cattle are numerous (Robertson & Mixner, 1956; Paterson, 1957; Brush, 1958, I96o; Saba, 1964) but less information is available concerning blood plasma glucocorticoid levels in calves (Shaw, Dutta & Nichols, 196o; Shaw & Nichols, 1962, I964). As a rule, determinations have been made of plasma free I7hydroxycorticosteroids (I 7-0HCS) covering the largest fraction of adrenal cortical secretion, including the main cortical hormone in cattle, cortisol (Hechter et al., I95I; Estergreen, 1964; Whipp, Weber, Usenik & Good, I967) along with cortisone and possibly other steroids giving the Porter-Silber reaction. Except for a few examinations in the first d ays of postnatal life (Holm, Parker & Galligan, 1961 ), no data are available on plasma q-OHCS levels of calves, either in physiological or pathological states. The object of this study was to determine plasma I 7-0HCS levels in diarrhoeic calves during their early postnatal life and thereby contribute to an understanding of adrenocortical activity in this most important disease of neonatal calves.
PLASMA CORTICOSTEROIDS IN CALVES
373
MATERIALS AND METHODS
In total, 248 determinations of blood plasma I 7-0HCS levels were made in I 67 calves of the red-spotted breed aged between I hour and 36 days. Of these, I 73 determinations were made in healthy calves and 75 were made in diarrhoeic animals. Thirty-three calves were housed in the Institute, the remainder on five farms in the district. The animals were divided into six age groups: the number of animals in each group is shown in Fig. I. Diarrhoeic calves were examined in various stages of disease and at various times in its course. Calves with clinical evidence of diarrhoea only are referred to as affected with "mild" signs of disease; those with disturbances in the general state of health, e.g. inappetence, apathy and signs of dehydration are referred to as affected with " severe" signs of disease. Blood specimens were obtained from the jugular vein in the morning and chilled immediately after collection. Plasma was stored in the frozen state . The concentration of free I 7-0HCS was determined by the Porter-Silber reaction (Dvorak, I g67 ). The statistical significance of the differences of mean values was assessed by the t-test. RESULTS
Plasma free 17-0HCS values obtained in healthy calves of various ages are shown in Fig. r. The highest concentration was found in the first I6 hours of 15
12
e
Diarrhoeic calv es
17
•,
9
'::l "'
33
·-
U)
0
i§
Healthy calves
I',,',,J
12
6Q
o
6
~
1
6 7
/
'•/
38 36
(()
'
""'-'-
43
"-
.;.
~
cO
2 81
C\i '
I[)
T • / 1
/
19
(()
""'J>
N
hrs
age
days
Fig. 1. Plasma 17-0HCS levels in healthy and diarrhoeic calves aged 1 hour to 36 days. The numbers of animals in each group is shown beside the appropriate means and standard deviations.
374
BRITISH VETERINARY JOURNAL,
I27,
8
life, and this level was significantly higher (P < o·oi) than that determined at other ages. A significant difference (P < o·o5) was also found between levels in calves aged I-3 days and in the four subsequent age groups. The results obtained in diarrhoeic calves are also plotted in Fig. I. It can be seen that these values, too, are suggestive of age differences. In general, the plasma I 7-0HCS levels of diarrhoeic calves were higher than in healthy animals; this difference was significant (P < o·os) in calves aged I-3 ,4-7 and 8-14 days. Variation in individual, diseased calves was generally higher than in healthy animals. Individual and mean values obtained for diarrhoeic calves with mild and severe symptoms of disease in individual age groups are shown in Table I. It will be seen that the I 7-0HCS values in severely affected calves were markedly in excess of those found in calves with mild forms of disease only at I -3 days of age; the latter being generally identical to 17-0HCS levels found in healthy calves. In the next two age groups, in which diarrhoea occurred most frequently, the I 7-0HCS levels were higher in calves with mild signs of disease than in severely affected animals. The difference of their means was significant (P < o·os) at 4-7 days of age. Frankly low levels not exceeding 3 ttgf iOo ml were relatively rare, occurring in approximately the same proportion in both categories. TABLE I. PLASMA I 7·0HCS LEVELS IN FIVE AGE GROUPS OF DIARRHOEIC CALVES WITH SI G NS OF MILD AND SEVERE DISEASE
Age of calves (days )
I-3 4-7 8-I4 I 5-2 I 22-36
Mild diarrhoea No. of calves I 7-0HCS (Jlg/ Ioo ml )
7 8 I9 4 4
7"4 ± 3·0* 7•6 ± 2"3 6·2 ± 2·8 3"4 ± I·3 4"9 ± 0·8
Severe diarrhoea I 7-0HCS No. of calves (Jlg/ IOO ml )
5 9 I4 3 2
I0·9 ± 5"3* 5"4± I·7 4·8 ±2· I 3·6 ± I·o s-o ± I·6
* Mean ± standard deviation The I 7-0HCS levels were apparently not affected by either body temperature or different housing, management and feeding practices on individual farms. A possible explanation for individual differences in some age groups can be seen in the results obtained upon repeat examinations of diarrhoeic cases of longer duration. In nine such animals, the clinical condition of which was unchanged or impaired when re-examined 1-9 days later, the mean I 7-0HCS levels were either unchanged or had decreased from 6·I to 4·4 t-tg / IOo ml. In seven other calves that showed clinical improvement or recovery when reexamined 3-10 days later, the mean I7-0HCS levels had, however, also decreased from 5·7 to 3·7 ttg f iOo ml. Three calves that died during the first day after examination had I7-0HCS concentrations of Io·o, 7·0 and 6·2 ttgfwo ml at 6, I 1 and 31 days of age, respectively, which implies that their I 7-0HCS levels were increased compared with mean values for both healthy and diseased animals of the same age.
PLASMA CORTICOSTEROIDS IN CALVES
375
DISCUSSION
The plasma free I 7-0HCS levels obtained in the present study in healthy calves are, except for the youngest animals, basically similar to those described by Shaw & Nichols (I 962, I 964) for older calves. The relatively high levels found in healthy calves I-I 6 hours after birth are, no doubt, of physiological significance in that they can contribute to the adaptation of the neonate to new conditions of extra-uterine life. They correspond, to a large degree, to increased I 7-0HCS levels of cows in late pregnancy and at parturition as reported by Paterson (I957) and Brush (I958). They may be induced by an increased adrenocortical production by calves themselves as suggested by our results obtained with the youngest calves on incubation of adrenal sections stimulated with ACTH in vitro. They are in accord with the qualitatively altered production in favour of cortisol, but not with the rate of its secretion, which is low in newborn calves (Balfour, I962 ). One cannot even exclude the possibility that the biological half-life of cortisol in the blood is prolonged as in newborn children (Short, I 962). In comparison with changes in plasma I 7-0HCS levels found during the postnatal development of piglets (Dvorak, I 967) the plasma I 7-0HCS levels of calves are lower, and the age differences are relatively small and limited to the neonatal stage. Both animal species, however, differ basically from children who have slightly lower plasma I 7-0HCS concentration at birth than at a later age (Short, I962). In rats, too, the basal production of corticosteroids during the first two weeks of life is lower than in adult life (Bartova, I963). The significantly increased I7-0HCS levels of diarrhoeic calves at I-I4 days of age are suggestive of increased adrenocortical activity. This is in keeping with previous observations on increased corticosteroid production as indicated indirectly by the enlarged adrenals of calves dying from diarrhoea (Hawkins et al., I959) and by the decreased ascorbic acid concentration of the adrenal in calves with pathological changes in the gastro-intestinal tract (Dvorak, Gilka & Patka, 1970) as well as by haematological findings in diarrhoeic calves (Patka & Dvorak, I 970). The results reported here for diarrhoeic calves could be anticipated because the infectious agents, endotoxins, histamine and some other factors which may be involved in this disease operate as stressinducing stimuli. That even the youngest healthy calves are able to respond to ACTH injection or to insulin hypoglycaemia by increased I7-0HCS levels has been demonstrated (Dvorak, I968, I970). Worthy of note are lower I7-0HCS values in "severely" compared to "mildly" affected calves. This might be accounted for by increased consumption and a higher metabolic rate in the animal concerned with homeostasis. One cannot, however, exclude the possibility, as suggested by our findings, that some diarrhoeic calves do not react to insulin hypoglycaernia (Dvorak, I 97 I), and that the function of the hypothalamus-pituitary-adrenocortical system may be impaired or become, to some extent, less efficient as a result of exposure to severe and persistent stress. Nevertheless, lower plasma I 7-0HCS levels in animals with diarrhoea of longer duration may not necessarily be indicative of
BRITISH VETERINARY JOURNAL, I27, 8
the failure of the gland to increase I 7-0HCS secretion. A single examination of the circulating corticosteroid level provides information merely about the state at the time of examination. Only an increased concentration is an unmistakable sign of adrenocortical activity. A few cases where the calves had higher I 7-0HCS values prior to death are not suggestive of adrenocortical insufficiency in the terminal stage of disease. Lower I 7-0HCS levels in recovered animals are in keeping with observations made in human medicine (Cornil, Copinschi, Leclerq & Franckson, Ig68). REFERENCES
BALFOUR, W. E. (I962). Br. med. Bull. 18, I I4. BARTOVA, A. (I963). Cslka. Fysiol. 12, 3I 1. BRusH, M.G. (I958). ]. Endocr. 17, 381. BRUSH, M.G. (I96o) . ]. Endocr. 21, I55· CORNIL, A., COPINSCHI, G., LECLERQ., R. & FRANCKSON,j. R. M. ( I968). Actaendocr. Copnh. s8, I. DvoRAK, M . ( I967). Vet. Med. Prague, 12, 43· DvoRAK, M. ( I968). Cslka. Fysiol. 17, 252. DvoRAK, M. ( I97I ). Zentbl. VetMed. A, in press. DvoRAK, M. , GILKA, F. & PATKA,j. (I970). Vet. Med. Prague, 15, 53· EsTERGREEN, V . L. ( I964). ]. Dairy Sci. 47, I I5. HAWKINS, G. M. , Rov, J. H. B., SHILLAM, K. W. G., CREATOREx, J. C. & INGRAM, P. L. (I959). Br. ]. Nutr. 13, 447· HECHTER, 0., ZAFFARONI, A., jACOBSEN, R. P. , LEvY, H., jEANLoz, R. W., ScHENKER, V. & PINCus, G . (I95I). Recent Prog. Horm. Res. 6, 2I5. HoLM, L. W., PARKER, H. R. & GALLIGAN, S. J. (I96I ). Am.]. Obstet. Gynec. 81, 1000. LINDT, S. (I962). Dtsch. tieriirztl. Wschr. 6g, 1. MOLL, T. ( I965). ]. Am. vet. med. Ass. 147, I364. PATERSON, J. Y. F. (I957). ]. camp. Path. Ther. 67, I65. PATKA, ]. & DvoRAK, M. ( I970). Documenta vet. Brno, in press. RoBERTSON, W. G. & MIXNER, J. P. ( I956). ]. Dairy Sci. 39, 589. SABA, N. ( I964). ]. Endocr. 28, I39· SELYE, H. (I946). ]. clin. Endocr. 6, I I7. SHAW, K. E., DuTTA, S. & NicHoLs, R. E. ( I96o). Am.]. vet. Res. 21, 52. SHAW, K. E. & NICHOLS, R. E . (Ig62 ). Am.]. vet. Res. 23, I2I7. SHAW, K. E . & NrcHOLs, R. E. (Ig64). Am.]. vet. Res. 25, 252. SHORT, R. V. ( I962 ). Br. med. Bull. 18, 106. WHIPP, S.C., WEBER, A. F., UsENIK, E. A. & GooD, A. L. (I967). Am.]. vet. Res. 28, 671. (Accepted for publication I I March I97I) Taux du plasma en 17-hydroxycorticosteroide chez les veaux bien portants et diarrhtHques (Dvorak) Resume. Les taux du plasma en I7-hydroxycorticosteroide libre (I7-0HCS) varient avec
!'age chez les veaux bien portants d'une race a taches rouges. On a trouve Ia plus forte concentration chez les veaux nouveaux-nes pendant leurs seize premieres heures de vie. Les valeurs de 17-0HCS observees chez les veaux diarrheiques variaient aussi avec !'age. Cependant Ia concentration en 17-0HCS chez les veaux diarrheiques de I a r4jours etait de fac;on significative plus elevee que celle d es animaux en bonne sante au meme age. Plasma 17-Hydroxycorticosteroidkonzentration (im Blut) gesunder oder an Durchfallleidender Kalber (Dvorak) Zusammenfassung. Plasma I 7-Hydroxycorticosteroid (I 7-0HCS) konzentrationen bei
PLASMA CORTICOSTEROIDS I N CALVES
377
gesunden Kalbern der rotgefteckten Rasse waren je nach dem Alter verschieden. Die hochste Konzentration fand sich bei neugeborenen Kalbern und zwar in den ersten I6 Stunden. Die bei an Diarrhoeleidenden K albern gefundenen Werte waren ebenfalls je nach dem Alter verschieden, jedoch waren sie bei ihnen im Alter von 1-14 Tagen signifikant hoher als bei g leichaltrigen gesunden Tieren. Niveles plasnuiticos de los 17-hidroxicorticoesteroides en terneras sanas y con diarrea (Dvoi-ak) Resumen. Los niveles de I 7-hidroxicorticoesteroides libres (I 7-0HCS) en plasma de las terneras sanas de Ia raza con manchas rajas variaron de acuerdo con Ia edad de los animales. Las concentraciones mas altas se encontraron en las terneras recien nacidas durante las primeras I 6 horas de Ia vida. Los valores de 1 7-0HCS observados en tern eras diarreicas tam bien variaron con Ia edad. Sin embargo, las concentraciones de I 7-0HCS en tern eras diarreicas entre el primero y decimocuarto dia de edad fueron significativamente mas altas que en los animales sanos de Ia misma edad.
PLASMA 17-HYDROXYCORTICOSTEROID LEVELS IN HEALTHY AND DIARRHOEIC CALVES BY M. DvoR.A.
K
Veterinary Research Institute, Brno, Czechoslovakia
SUMMARY
Plasma free I 7-hydroxycorticosteroid (I 7-0HCS) levels of healthy calves of the red-spotted breed varied with age. The highest concentration was found in newborn calves during the first I6 hours of life. The I 7-0HCS values observed in diarrhoeic calves also varied with age. However, the I 7-0HCS concentration in diarrhoeic calves aged I- I4 days was significantly higher than that of healthy animals of the same age. INTRODUCTION
Adrenocortical activity, which plays an important role in the general adaptation syndrome (Selye, 1946), has not received much attention in calves. According to Balfour (I962 ) and Short (1962), calves develop quantitative and qualitative changes in corticosteroid secretion during postnatal life. Moll ( I 965) favours the view that calves are born with immature adrenals and are poorly equipped to cope with major environmental changes. Adrenal cortical insufficiency in calves .with prolonged intrauterine development was reported by Holm, Parker & Galligan (1961 ). Lindt (1962) described adrenal cortical insufficiency in calves with colisepticaemia associated with adrenal haemorrhages. References to glucocorticoid levels in blood plasma of adult cattle are numerous (Robertson & Mixner, 1956; Paterson, 1957; Brush, 1958, I96o; Saba, 1964) but less information is available concerning blood plasma glucocorticoid levels in calves (Shaw, Dutta & Nichols, 196o; Shaw & Nichols, 1962, I964). As a rule, determinations have been made of plasma free I7hydroxycorticosteroids (I 7-0HCS) covering the largest fraction of adrenal cortical secretion, including the main cortical hormone in cattle, cortisol (Hechter et al., I95I; Estergreen, 1964; Whipp, Weber, Usenik & Good, I967) along with cortisone and possibly other steroids giving the Porter-Silber reaction. Except for a few examinations in the first d ays of postnatal life (Holm, Parker & Galligan, 1961 ), no data are available on plasma q-OHCS levels of calves, either in physiological or pathological states. The object of this study was to determine plasma I 7-0HCS levels in diarrhoeic calves during their early postnatal life and thereby contribute to an understanding of adrenocortical activity in this most important disease of neonatal calves.
PLASMA CORTICOSTEROIDS IN CALVES
373
MATERIALS AND METHODS
In total, 248 determinations of blood plasma I 7-0HCS levels were made in I 67 calves of the red-spotted breed aged between I hour and 36 days. Of these, I 73 determinations were made in healthy calves and 75 were made in diarrhoeic animals. Thirty-three calves were housed in the Institute, the remainder on five farms in the district. The animals were divided into six age groups: the number of animals in each group is shown in Fig. I. Diarrhoeic calves were examined in various stages of disease and at various times in its course. Calves with clinical evidence of diarrhoea only are referred to as affected with "mild" signs of disease; those with disturbances in the general state of health, e.g. inappetence, apathy and signs of dehydration are referred to as affected with " severe" signs of disease. Blood specimens were obtained from the jugular vein in the morning and chilled immediately after collection. Plasma was stored in the frozen state . The concentration of free I 7-0HCS was determined by the Porter-Silber reaction (Dvorak, I g67 ). The statistical significance of the differences of mean values was assessed by the t-test. RESULTS
Plasma free 17-0HCS values obtained in healthy calves of various ages are shown in Fig. r. The highest concentration was found in the first I6 hours of 15
12
e
Diarrhoeic calv es
17
•,
9
'::l "'
33
·-
U)
0
i§
Healthy calves
I',,',,J
12
6Q
o
6
~
1
6 7
/
'•/
38 36
(()
'
""'-'-
43
"-
.;.
~
cO
2 81
C\i '
I[)
T • / 1
/
19
(()
""'J>
N
hrs
age
days
Fig. 1. Plasma 17-0HCS levels in healthy and diarrhoeic calves aged 1 hour to 36 days. The numbers of animals in each group is shown beside the appropriate means and standard deviations.
374
BRITISH VETERINARY JOURNAL,
I27,
8
life, and this level was significantly higher (P < o·oi) than that determined at other ages. A significant difference (P < o·o5) was also found between levels in calves aged I-3 days and in the four subsequent age groups. The results obtained in diarrhoeic calves are also plotted in Fig. I. It can be seen that these values, too, are suggestive of age differences. In general, the plasma I 7-0HCS levels of diarrhoeic calves were higher than in healthy animals; this difference was significant (P < o·os) in calves aged I-3 ,4-7 and 8-14 days. Variation in individual, diseased calves was generally higher than in healthy animals. Individual and mean values obtained for diarrhoeic calves with mild and severe symptoms of disease in individual age groups are shown in Table I. It will be seen that the I 7-0HCS values in severely affected calves were markedly in excess of those found in calves with mild forms of disease only at I -3 days of age; the latter being generally identical to 17-0HCS levels found in healthy calves. In the next two age groups, in which diarrhoea occurred most frequently, the I 7-0HCS levels were higher in calves with mild signs of disease than in severely affected animals. The difference of their means was significant (P < o·os) at 4-7 days of age. Frankly low levels not exceeding 3 ttgf iOo ml were relatively rare, occurring in approximately the same proportion in both categories. TABLE I. PLASMA I 7·0HCS LEVELS IN FIVE AGE GROUPS OF DIARRHOEIC CALVES WITH SI G NS OF MILD AND SEVERE DISEASE
Age of calves (days )
I-3 4-7 8-I4 I 5-2 I 22-36
Mild diarrhoea No. of calves I 7-0HCS (Jlg/ Ioo ml )
7 8 I9 4 4
7"4 ± 3·0* 7•6 ± 2"3 6·2 ± 2·8 3"4 ± I·3 4"9 ± 0·8
Severe diarrhoea I 7-0HCS No. of calves (Jlg/ IOO ml )
5 9 I4 3 2
I0·9 ± 5"3* 5"4± I·7 4·8 ±2· I 3·6 ± I·o s-o ± I·6
* Mean ± standard deviation The I 7-0HCS levels were apparently not affected by either body temperature or different housing, management and feeding practices on individual farms. A possible explanation for individual differences in some age groups can be seen in the results obtained upon repeat examinations of diarrhoeic cases of longer duration. In nine such animals, the clinical condition of which was unchanged or impaired when re-examined 1-9 days later, the mean I 7-0HCS levels were either unchanged or had decreased from 6·I to 4·4 t-tg / IOo ml. In seven other calves that showed clinical improvement or recovery when reexamined 3-10 days later, the mean I7-0HCS levels had, however, also decreased from 5·7 to 3·7 ttg f iOo ml. Three calves that died during the first day after examination had I7-0HCS concentrations of Io·o, 7·0 and 6·2 ttgfwo ml at 6, I 1 and 31 days of age, respectively, which implies that their I 7-0HCS levels were increased compared with mean values for both healthy and diseased animals of the same age.
PLASMA CORTICOSTEROIDS IN CALVES
375
DISCUSSION
The plasma free I 7-0HCS levels obtained in the present study in healthy calves are, except for the youngest animals, basically similar to those described by Shaw & Nichols (I 962, I 964) for older calves. The relatively high levels found in healthy calves I-I 6 hours after birth are, no doubt, of physiological significance in that they can contribute to the adaptation of the neonate to new conditions of extra-uterine life. They correspond, to a large degree, to increased I 7-0HCS levels of cows in late pregnancy and at parturition as reported by Paterson (I957) and Brush (I958). They may be induced by an increased adrenocortical production by calves themselves as suggested by our results obtained with the youngest calves on incubation of adrenal sections stimulated with ACTH in vitro. They are in accord with the qualitatively altered production in favour of cortisol, but not with the rate of its secretion, which is low in newborn calves (Balfour, I962 ). One cannot even exclude the possibility that the biological half-life of cortisol in the blood is prolonged as in newborn children (Short, I 962). In comparison with changes in plasma I 7-0HCS levels found during the postnatal development of piglets (Dvorak, I 967) the plasma I 7-0HCS levels of calves are lower, and the age differences are relatively small and limited to the neonatal stage. Both animal species, however, differ basically from children who have slightly lower plasma I 7-0HCS concentration at birth than at a later age (Short, I962). In rats, too, the basal production of corticosteroids during the first two weeks of life is lower than in adult life (Bartova, I963). The significantly increased I7-0HCS levels of diarrhoeic calves at I-I4 days of age are suggestive of increased adrenocortical activity. This is in keeping with previous observations on increased corticosteroid production as indicated indirectly by the enlarged adrenals of calves dying from diarrhoea (Hawkins et al., I959) and by the decreased ascorbic acid concentration of the adrenal in calves with pathological changes in the gastro-intestinal tract (Dvorak, Gilka & Patka, 1970) as well as by haematological findings in diarrhoeic calves (Patka & Dvorak, I 970). The results reported here for diarrhoeic calves could be anticipated because the infectious agents, endotoxins, histamine and some other factors which may be involved in this disease operate as stressinducing stimuli. That even the youngest healthy calves are able to respond to ACTH injection or to insulin hypoglycaemia by increased I7-0HCS levels has been demonstrated (Dvorak, I968, I970). Worthy of note are lower I7-0HCS values in "severely" compared to "mildly" affected calves. This might be accounted for by increased consumption and a higher metabolic rate in the animal concerned with homeostasis. One cannot, however, exclude the possibility, as suggested by our findings, that some diarrhoeic calves do not react to insulin hypoglycaernia (Dvorak, I 97 I), and that the function of the hypothalamus-pituitary-adrenocortical system may be impaired or become, to some extent, less efficient as a result of exposure to severe and persistent stress. Nevertheless, lower plasma I 7-0HCS levels in animals with diarrhoea of longer duration may not necessarily be indicative of
BRITISH VETERINARY JOURNAL, I27, 8
the failure of the gland to increase I 7-0HCS secretion. A single examination of the circulating corticosteroid level provides information merely about the state at the time of examination. Only an increased concentration is an unmistakable sign of adrenocortical activity. A few cases where the calves had higher I 7-0HCS values prior to death are not suggestive of adrenocortical insufficiency in the terminal stage of disease. Lower I 7-0HCS levels in recovered animals are in keeping with observations made in human medicine (Cornil, Copinschi, Leclerq & Franckson, Ig68). REFERENCES
BALFOUR, W. E. (I962). Br. med. Bull. 18, I I4. BARTOVA, A. (I963). Cslka. Fysiol. 12, 3I 1. BRusH, M.G. (I958). ]. Endocr. 17, 381. BRUSH, M.G. (I96o) . ]. Endocr. 21, I55· CORNIL, A., COPINSCHI, G., LECLERQ., R. & FRANCKSON,j. R. M. ( I968). Actaendocr. Copnh. s8, I. DvoRAK, M . ( I967). Vet. Med. Prague, 12, 43· DvoRAK, M. ( I968). Cslka. Fysiol. 17, 252. DvoRAK, M. ( I97I ). Zentbl. VetMed. A, in press. DvoRAK, M. , GILKA, F. & PATKA,j. (I970). Vet. Med. Prague, 15, 53· EsTERGREEN, V . L. ( I964). ]. Dairy Sci. 47, I I5. HAWKINS, G. M. , Rov, J. H. B., SHILLAM, K. W. G., CREATOREx, J. C. & INGRAM, P. L. (I959). Br. ]. Nutr. 13, 447· HECHTER, 0., ZAFFARONI, A., jACOBSEN, R. P. , LEvY, H., jEANLoz, R. W., ScHENKER, V. & PINCus, G . (I95I). Recent Prog. Horm. Res. 6, 2I5. HoLM, L. W., PARKER, H. R. & GALLIGAN, S. J. (I96I ). Am.]. Obstet. Gynec. 81, 1000. LINDT, S. (I962). Dtsch. tieriirztl. Wschr. 6g, 1. MOLL, T. ( I965). ]. Am. vet. med. Ass. 147, I364. PATERSON, J. Y. F. (I957). ]. camp. Path. Ther. 67, I65. PATKA, ]. & DvoRAK, M. ( I970). Documenta vet. Brno, in press. RoBERTSON, W. G. & MIXNER, J. P. ( I956). ]. Dairy Sci. 39, 589. SABA, N. ( I964). ]. Endocr. 28, I39· SELYE, H. (I946). ]. clin. Endocr. 6, I I7. SHAW, K. E., DuTTA, S. & NicHoLs, R. E. ( I96o). Am.]. vet. Res. 21, 52. SHAW, K. E. & NICHOLS, R. E . (Ig62 ). Am.]. vet. Res. 23, I2I7. SHAW, K. E . & NrcHOLs, R. E. (Ig64). Am.]. vet. Res. 25, 252. SHORT, R. V. ( I962 ). Br. med. Bull. 18, 106. WHIPP, S.C., WEBER, A. F., UsENIK, E. A. & GooD, A. L. (I967). Am.]. vet. Res. 28, 671. (Accepted for publication I I March I97I) Taux du plasma en 17-hydroxycorticosteroide chez les veaux bien portants et diarrhtHques (Dvorak) Resume. Les taux du plasma en I7-hydroxycorticosteroide libre (I7-0HCS) varient avec
!'age chez les veaux bien portants d'une race a taches rouges. On a trouve Ia plus forte concentration chez les veaux nouveaux-nes pendant leurs seize premieres heures de vie. Les valeurs de 17-0HCS observees chez les veaux diarrheiques variaient aussi avec !'age. Cependant Ia concentration en 17-0HCS chez les veaux diarrheiques de I a r4jours etait de fac;on significative plus elevee que celle d es animaux en bonne sante au meme age. Plasma 17-Hydroxycorticosteroidkonzentration (im Blut) gesunder oder an Durchfallleidender Kalber (Dvorak) Zusammenfassung. Plasma I 7-Hydroxycorticosteroid (I 7-0HCS) konzentrationen bei
PLASMA CORTICOSTEROIDS I N CALVES
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gesunden Kalbern der rotgefteckten Rasse waren je nach dem Alter verschieden. Die hochste Konzentration fand sich bei neugeborenen Kalbern und zwar in den ersten I6 Stunden. Die bei an Diarrhoeleidenden K albern gefundenen Werte waren ebenfalls je nach dem Alter verschieden, jedoch waren sie bei ihnen im Alter von 1-14 Tagen signifikant hoher als bei g leichaltrigen gesunden Tieren. Niveles plasnuiticos de los 17-hidroxicorticoesteroides en terneras sanas y con diarrea (Dvoi-ak) Resumen. Los niveles de I 7-hidroxicorticoesteroides libres (I 7-0HCS) en plasma de las terneras sanas de Ia raza con manchas rajas variaron de acuerdo con Ia edad de los animales. Las concentraciones mas altas se encontraron en las terneras recien nacidas durante las primeras I 6 horas de Ia vida. Los valores de 1 7-0HCS observados en tern eras diarreicas tam bien variaron con Ia edad. Sin embargo, las concentraciones de I 7-0HCS en tern eras diarreicas entre el primero y decimocuarto dia de edad fueron significativamente mas altas que en los animales sanos de Ia misma edad.