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Circadian rhythm in blood sugar and adrenomedullary hormonal concentrations in an avian and a reptilian species
GENERAL
AND
Circadian
COMPARATIVE
Rhythm in Blood Sugar and Adrenomedullary Hormonal Concentrations in an Avian and a Reptilian Species
SANTASREE Histophysiology
46, 110-112 (1982)
ENDOCRINOLOGY
CHOUDHURY,’
Laboratory,
Department
TAPAS
K. DE, B. R. MAITI,
of Zoology, University of Calcutta, Calcutta 700 019, India Accepted
January
AND ASOK GHOSH 35 Ballygunge
Circular
Road,
5, 1981
The aim of the present investigation was to ascertain the circadian rhythm in the concentration of blood glucose and adrenal medullary hormones in the parakeet and the turtle. These substances were measured four times (0600, 1200, 1800, and ?400 hr) over a 24-hr period. The concentration of blood glucose and adrenal adrenaline and noradrenaline was higher during the day (0600 through 1800 hr) than that noted at night (2400 hr). The pattern of fluctuation was almost similar in both the animal species. The finding suggests that there is a clear circadian rhythm in the concentration of these substances in the parakeet and the turtle, and that this may be due to fluctuation in the activity of the animals.
It is fairly well known that in mammals, the blood glucose concentration is higher at night than during the day (Allcroft, 1933; Preston and Ndumbe, 1961; Mills, 1966; Pauly and Scheving, 1967). But in birds (chicks), the situation is the reverse of that of mammals (Twiest and Smith, 1970). In the rat, adrenal medullary hormonal concentration is also diurnally altered (more at night than during the day) (Von Euler, 1956), but it is not known so far in birds. In reptiles, there is no information concerning diurnal concentration of blood glucose or adrenomedullary hormones (Gans, 1970). Therefore, adrenaline and noradrenaline in the adrenal gland and blood glucose were measured during a 24-hr period in a bird and a reptile and is reported in the current communication. MATERIALS
AND METHODS
Adult male rose-ringed parakeets, Psitracula liramen’, and soft-shelled turtles, Lissemys punctata punctata (Bonnoterre), were trapped from natural population and maintained in controlled laboratory condition (temperature 22-2X, light: 0600- 1800 hri24 hr) for 3-5 days before being subjected to investigation. Food (parakeet: gram and wheat, turtle: small fish and earthworm) and water were available ad libitum to the * Junior Research Fellow, Indian National Science Academy.
animals. Blood glucose and catecholamine concentrations were measured four times (0600, 1200, 1800 and 2400 hr) over a 24-hr period, from different groups of animals in parakeets and from the same groups of animals in turtles. Ten specimens were used for each observation. In both the species blood sugar was studied in unfed (5l/4 hr) animals. Blood was drawn from the heart of the animals by heparinized syringe and measured by the method of Bergmeyer (1963). Adrenaline and noradrenaline contents of the adrenal gland were purified (Taylor and Laverty, 1969) and measured (Van Euler, 1950). The data were analyzed by Student’s t test (Snedecor, 1957).
RESULTS
Blood sugar. The concentration of blood sugar was much higher in the parakeet than in the turtle (Figs. 1 and 2). Diurnal study revealed that in both species, the concentration of blood sugar was higher during 0600 hr through 1800 hr than that recorded at 2400 hr. But the significant difference was noted between 1800 hr and 2400 hr in the parakeet, and between 1200 hr and 2400 hr in the turtle (Figs. 1 and 2). Adrenaline and noradrenaline. The catecholamine content of the adrenal gland was generally higher in the parakeet than that in the turtle. The concentration of adrenaline and noradrenaline was almost in equal proportion in the parakeet, while that of adrenaline was lower than noradrenaline in the 110
001M480/82/010110-03$01.00/O Copyright @ 1982 by Academic Press, Inc. All rights of reproduction in any form reserved.
CIRCADIAN x 00 0 0
RHYTHM
BLOOD GLUCOSE ADRENALINE ADRENALINE NORADRENALINE NORADRENALINE
IN BIRD AND REPTILE x BLOOD GLUCOSE 0 AORENALINE . NORADRENALINE
G; 2 I3.5 ”
111
90
1
P “i 3.0 ; z I 2.5 g 8 8 2.0 =
t 15011.0 12.00
0.6
P ’ s
2
3.5 ii!
1.5 y
5
i 1
i 18.00 TIME
24.00 (CLOCK
06.00 HOUR)-
12.00
FIG. 1. The graphs show circadian rhythm in the concentration of blood glucose and adrenomedullary hormones in the adult male parakeet. Level of significance between the highest (1800 hr) and lowest (2400 h) values in the blood glucose: P < 0.05, and in the adrenaline and noradrenaline: P < 0.01. 01 12.00
turtle (Figs. I and 2). A 24-hr study of adrenal catecholamines showed that both adrenaline and noradrenaline concentrations were diurnally altered, almost similarly to that of blood glucose, in the parakeet and turtle (Figs. 1 and 2).
18.00 TIME
24.00 (CLOCK
06.00 12.00 HOUR )d
FIG. 2. Diurnal fluctuation in blood glucose and adrenomedullary hormonal concentrations in the softshelled turtle (level of significance between highest and lowest values, blood glucose: P < 0.001, adrenaline: P < 0.001, and noradrenaline: P < 0.01).
DISCUSSION
The present study reveals that there is a diurnal rhythm in the concentration of both the blood glucose and adrenomedullary hormones (adrenaline and noradrenaline) in both the parakeet and the turtle. The diurnal fluctuation in the concentration of these substances may be due to fluctuation in the activity of animals. During the day these animals are active which may account for a rise in the concentration of adrenomedullary hormones and consequently the blood sugar concentration (since these hormones are hyperglycemic agents cf. Sturkie, 1976;
Ghosh, 1977). At night the animals remain at rest resulting in a decline in the concentration of these substances. In essence, the circadian rhythm in the concentration of blood glucose and adrenomedullary hormones in both the parakeet and the turtle is indicated. ACKNOWLEDGMENTS This work was supported by grants from the Indian National Science Academy (0910/P 18/7753, the UGC Assistance to teachers (F 25/8/l 1461/80), and from the UGC Special Assistance Programme to the Department of Zoology, University of Calcutta.
112
CHOIJDHURY
REFERENCES Allcroft. W. M. (1933). Diurnal variation in blood sugar level of the lactating cow. Biochem. J. 27, 1820- 1823. Bergmeyer. H. V. (1963). “Methods of Enzymatic Analysis.” pp. 123-130. Academic Press, New York. Gans, C. (1970). “Biology of the Reptilia,” Vol. 3: “Morphology C” Academic Press, New York. Ghosh, A. (1977). Cytophysiology of the avian adrenal medulla. Int. Rev. Cytol. 49, 253-284. Mills, J. N. (1966). Human circadian rhythms. Physiol. Rev. 46, 128-171. Pauly, J. E., and Scheving, L. E. (1967). Circadian rhythms in blood glucose and the effect of different lighting schedules, hypophysectomy, adrenal medullectomy and starvation. Amer. J. Anat. 120, 627-636.
ET
AL.
Preston, T. R., and Ndumbe, R. D. (1961). Diurnal variations in blood sugar concentration in ruminating calves. Brit. J. Nutr. 15, 281-285. Snedecor, G. W. (1956). “Statistical Methods,” 4th ed. Iowa State Univ. Press, Ames. Sturkie. P. D. (1976). “Avian Physiology,” 3rd ed. Springer-Verlag. New York/Heidelberg/Berlin. Taylor, K. M., and Laverty, R. (1969). The metabolism of triatiated dopamine in regions of the rat brain. In viva. I. The separation of catecholamines and their metabolites. J. Neurochem. 16, 1361-1366. Twiest, G., and Smith, C. J. (1970). Circadian rhythm on blood glucose level of chickens. Comp. Biochem. Physiol. 32, 371-375. Von Euler, U. S. (1950). “Methods in Medical Research,” Vol. 2. Yearbook Pub., Chicago. Von Euler, U. S. (1956). “Noradrenaline.” C C Thomas, Springfield, Ill.
AND
Circadian
COMPARATIVE
Rhythm in Blood Sugar and Adrenomedullary Hormonal Concentrations in an Avian and a Reptilian Species
SANTASREE Histophysiology
46, 110-112 (1982)
ENDOCRINOLOGY
CHOUDHURY,’
Laboratory,
Department
TAPAS
K. DE, B. R. MAITI,
of Zoology, University of Calcutta, Calcutta 700 019, India Accepted
January
AND ASOK GHOSH 35 Ballygunge
Circular
Road,
5, 1981
The aim of the present investigation was to ascertain the circadian rhythm in the concentration of blood glucose and adrenal medullary hormones in the parakeet and the turtle. These substances were measured four times (0600, 1200, 1800, and ?400 hr) over a 24-hr period. The concentration of blood glucose and adrenal adrenaline and noradrenaline was higher during the day (0600 through 1800 hr) than that noted at night (2400 hr). The pattern of fluctuation was almost similar in both the animal species. The finding suggests that there is a clear circadian rhythm in the concentration of these substances in the parakeet and the turtle, and that this may be due to fluctuation in the activity of the animals.
It is fairly well known that in mammals, the blood glucose concentration is higher at night than during the day (Allcroft, 1933; Preston and Ndumbe, 1961; Mills, 1966; Pauly and Scheving, 1967). But in birds (chicks), the situation is the reverse of that of mammals (Twiest and Smith, 1970). In the rat, adrenal medullary hormonal concentration is also diurnally altered (more at night than during the day) (Von Euler, 1956), but it is not known so far in birds. In reptiles, there is no information concerning diurnal concentration of blood glucose or adrenomedullary hormones (Gans, 1970). Therefore, adrenaline and noradrenaline in the adrenal gland and blood glucose were measured during a 24-hr period in a bird and a reptile and is reported in the current communication. MATERIALS
AND METHODS
Adult male rose-ringed parakeets, Psitracula liramen’, and soft-shelled turtles, Lissemys punctata punctata (Bonnoterre), were trapped from natural population and maintained in controlled laboratory condition (temperature 22-2X, light: 0600- 1800 hri24 hr) for 3-5 days before being subjected to investigation. Food (parakeet: gram and wheat, turtle: small fish and earthworm) and water were available ad libitum to the * Junior Research Fellow, Indian National Science Academy.
animals. Blood glucose and catecholamine concentrations were measured four times (0600, 1200, 1800 and 2400 hr) over a 24-hr period, from different groups of animals in parakeets and from the same groups of animals in turtles. Ten specimens were used for each observation. In both the species blood sugar was studied in unfed (5l/4 hr) animals. Blood was drawn from the heart of the animals by heparinized syringe and measured by the method of Bergmeyer (1963). Adrenaline and noradrenaline contents of the adrenal gland were purified (Taylor and Laverty, 1969) and measured (Van Euler, 1950). The data were analyzed by Student’s t test (Snedecor, 1957).
RESULTS
Blood sugar. The concentration of blood sugar was much higher in the parakeet than in the turtle (Figs. 1 and 2). Diurnal study revealed that in both species, the concentration of blood sugar was higher during 0600 hr through 1800 hr than that recorded at 2400 hr. But the significant difference was noted between 1800 hr and 2400 hr in the parakeet, and between 1200 hr and 2400 hr in the turtle (Figs. 1 and 2). Adrenaline and noradrenaline. The catecholamine content of the adrenal gland was generally higher in the parakeet than that in the turtle. The concentration of adrenaline and noradrenaline was almost in equal proportion in the parakeet, while that of adrenaline was lower than noradrenaline in the 110
001M480/82/010110-03$01.00/O Copyright @ 1982 by Academic Press, Inc. All rights of reproduction in any form reserved.
CIRCADIAN x 00 0 0
RHYTHM
BLOOD GLUCOSE ADRENALINE ADRENALINE NORADRENALINE NORADRENALINE
IN BIRD AND REPTILE x BLOOD GLUCOSE 0 AORENALINE . NORADRENALINE
G; 2 I3.5 ”
111
90
1
P “i 3.0 ; z I 2.5 g 8 8 2.0 =
t 15011.0 12.00
0.6
P ’ s
2
3.5 ii!
1.5 y
5
i 1
i 18.00 TIME
24.00 (CLOCK
06.00 HOUR)-
12.00
FIG. 1. The graphs show circadian rhythm in the concentration of blood glucose and adrenomedullary hormones in the adult male parakeet. Level of significance between the highest (1800 hr) and lowest (2400 h) values in the blood glucose: P < 0.05, and in the adrenaline and noradrenaline: P < 0.01. 01 12.00
turtle (Figs. I and 2). A 24-hr study of adrenal catecholamines showed that both adrenaline and noradrenaline concentrations were diurnally altered, almost similarly to that of blood glucose, in the parakeet and turtle (Figs. 1 and 2).
18.00 TIME
24.00 (CLOCK
06.00 12.00 HOUR )d
FIG. 2. Diurnal fluctuation in blood glucose and adrenomedullary hormonal concentrations in the softshelled turtle (level of significance between highest and lowest values, blood glucose: P < 0.001, adrenaline: P < 0.001, and noradrenaline: P < 0.01).
DISCUSSION
The present study reveals that there is a diurnal rhythm in the concentration of both the blood glucose and adrenomedullary hormones (adrenaline and noradrenaline) in both the parakeet and the turtle. The diurnal fluctuation in the concentration of these substances may be due to fluctuation in the activity of animals. During the day these animals are active which may account for a rise in the concentration of adrenomedullary hormones and consequently the blood sugar concentration (since these hormones are hyperglycemic agents cf. Sturkie, 1976;
Ghosh, 1977). At night the animals remain at rest resulting in a decline in the concentration of these substances. In essence, the circadian rhythm in the concentration of blood glucose and adrenomedullary hormones in both the parakeet and the turtle is indicated. ACKNOWLEDGMENTS This work was supported by grants from the Indian National Science Academy (0910/P 18/7753, the UGC Assistance to teachers (F 25/8/l 1461/80), and from the UGC Special Assistance Programme to the Department of Zoology, University of Calcutta.
112
CHOIJDHURY
REFERENCES Allcroft. W. M. (1933). Diurnal variation in blood sugar level of the lactating cow. Biochem. J. 27, 1820- 1823. Bergmeyer. H. V. (1963). “Methods of Enzymatic Analysis.” pp. 123-130. Academic Press, New York. Gans, C. (1970). “Biology of the Reptilia,” Vol. 3: “Morphology C” Academic Press, New York. Ghosh, A. (1977). Cytophysiology of the avian adrenal medulla. Int. Rev. Cytol. 49, 253-284. Mills, J. N. (1966). Human circadian rhythms. Physiol. Rev. 46, 128-171. Pauly, J. E., and Scheving, L. E. (1967). Circadian rhythms in blood glucose and the effect of different lighting schedules, hypophysectomy, adrenal medullectomy and starvation. Amer. J. Anat. 120, 627-636.
ET
AL.
Preston, T. R., and Ndumbe, R. D. (1961). Diurnal variations in blood sugar concentration in ruminating calves. Brit. J. Nutr. 15, 281-285. Snedecor, G. W. (1956). “Statistical Methods,” 4th ed. Iowa State Univ. Press, Ames. Sturkie. P. D. (1976). “Avian Physiology,” 3rd ed. Springer-Verlag. New York/Heidelberg/Berlin. Taylor, K. M., and Laverty, R. (1969). The metabolism of triatiated dopamine in regions of the rat brain. In viva. I. The separation of catecholamines and their metabolites. J. Neurochem. 16, 1361-1366. Twiest, G., and Smith, C. J. (1970). Circadian rhythm on blood glucose level of chickens. Comp. Biochem. Physiol. 32, 371-375. Von Euler, U. S. (1950). “Methods in Medical Research,” Vol. 2. Yearbook Pub., Chicago. Von Euler, U. S. (1956). “Noradrenaline.” C C Thomas, Springfield, Ill.