l-THYROXINE, CORTISOL AND DIET AFFECT THE LEVEL OF AMYLASE IN THE PAROTID GLAND OF DEVELOPING RATS

1980 ◽  
Vol 87 (1) ◽  
pp. 65-71 ◽  
Author(s):  
MASAYOSHI KUMEGAWA ◽  
NORIHIKO MAEDA ◽  
TOSHIHIKO YAJIMA ◽  
TAISHIN TAKUMA ◽  
EIKO IKEDA ◽  
...  
Keyword(s):  
Body Weight ◽  
Enzyme Activity ◽  
Parotid Gland ◽  
Amylase Activity ◽  
Synergistic Effects ◽  
Dietary Factors ◽  
Adult Rats ◽  
Early Increase ◽  
Adrenalectomized Rats ◽  
Intact Rats

The effects of cortisol (10 μg/g body weight) and l-thyroxine (T4; 0·2 μg/g body weight) on the activity of parotid gland amylase in young rats were investigated. Administration of cortisol or T4 for 5 consecutive days from day 5 after birth caused the precocious appearance of amylase, T4 having almost twice the effect of cortisol. Cortisol and T4 did not have synergistic effects. In thyroidectomized-adrenalectomized rats, T4 increased amylase activity but cortisol did not. The increase in enzyme activity after day 20 was much less in rats thyroidectomized on day 10 than in rats adrenalectomized on day 10. These results suggest that T4 has a direct effect on the early increase of amylase activity (days 15–25) and that the action of glucocorticoid requires the presence of endogenous thyroid hormones. The hormone-induced level of amylase in intact rats was less than that of normal adult rats. Forced weaning of intact rats resulted in a further increase in amylase activity, suggesting that further amylase accumulation (after day 25) may be due to dietary factors.

THE EFFECT OF THYROID ADMINISTRATION ON THE PANCREATIC AMYLASE ACTIVITY OF HYPOPHYSECTOMIZED AND INTACT RATS

1963 ◽  
Vol 41 (6) ◽  
pp. 1373-1379 ◽  
Author(s):  
Madelaine O. Maykut ◽  
Margaret T. Nishikawara ◽  
R. E. Haist
Keyword(s):  
Body Weight ◽  
Thyroid Gland ◽  
Amylase Activity ◽  
Total Activity ◽  
Pancreatic Amylase ◽  
Hypophysectomized Rats ◽  
Dose Levels ◽  
Marked Atrophy ◽  
Intact Rats

The administration of desiccated thyroid gland to hypophysectomized rats prevented the marked atrophy of the pancreas which was consistently observed following hypophysectomy. Thyroid feeding at two dose levels led to a significant increase in the pancreatic amylase activity of hypophysectomized rats. This held whether the results were expressed as total activity or were given as activity per unit of body weight, per unit of pancreas, or per mg nitrogen. Except for the activity per unit of body weight, the amylase activity of the thyroid-treated hypophysectomized rats was significantly lower than the amylase activity in untreated, intact controls. In the thyroid-fed, hypophysectomized rats the amylase activity per unit of body weight was not significantly different from that of intact, untreated controls.Thyroid administration in intact rats resulted in a decrease in the pancreatic amylase activity.

THE SECRETION OF ANTIDIURETIC HORMONE IN RESPONSE TO HAEMORRHAGE AND THE FATE OF VASOPRESSIN IN ADRENALECTOMIZED RATS

1954 ◽  
Vol 11 (2) ◽  
pp. 165-176 ◽  
Author(s):  
M. GINSBURG
Keyword(s):  
Body Weight ◽  
Sodium Chloride ◽  
Antidiuretic Hormone ◽  
Intravenous Injection ◽  
Posterior Pituitary ◽  
Arterial Blood ◽  
Adrenalectomized Rats ◽  
Intact Rats

SUMMARY 1. The antidiuretic potency of arterial blood from adrenalectomized rats was greater than that from intact rats, but only if 2 or more ml. of blood were taken from each rat. It is concluded that the amounts of posterior pituitary antidiuretic hormone released during haemorrhage are greater in adrenalectomized than in intact rats. 2. The effect of haemorrhage on the antidiuretic potency of blood in adrenalectomized rats treated with sodium chloride or cortisone was not different from that in intact rats. 3. The disappearance of intravenously injected vasopressin (100 mU/100 g body weight) was retarded after adrenalectomy. Up to 48 hr after adrenalectomy this was due to a reduced capacity of the kidneys to remove vasopressin from the circulation. 4. Treatment with cortisone increased the rate of disappearance of vasopressin in adrenalectomized rats, but the rate was not restored to that observed in intact animals. 5. Treatment with sodium chloride did not affect the rate at which vasopressin was removed from the circulation of adrenalectomized rats. 6. The excretion of an antidiuretic agent in the urine which followed intravenous injection of vasopressin (100 mU/100 g) 48 hr after adrenalectomy was equivalent to 2·1% of the dose. This compared with an excretion of 6·7% of the dose in intact animals.

Factors Influencing Survival of Rats in Fasting

1957 ◽  
Vol 188 (2) ◽  
pp. 332-336 ◽  
Author(s):  
R. H. Rixon ◽  
J. A. F. Stevenson
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Metabolic Rate ◽  
Environmental Temperature ◽  
Body Weight Loss ◽  
Initial Body Weight ◽  
Adult Rats ◽  
Factors Influencing ◽  
The Individual ◽  
Intact Rats

The individual duration of survival of adult rats in complete fasting varied considerably; the range at an environmental temperature of 22°C was 6–16 days, at 2–5°C, 1–7 days, and in thyroidectomized animals at 22°C, 15–25 days. This variation in survival was not closely related to the initial body weight but was related to the individual proportionate body weight loss per day and the total proportionate weight loss sustained before death. The individual proportionate rate of weight loss has been correlated with the metabolic rate indicating that the former reflected the metabolic rate of the animal. The duration of survival in fasting has been correlated with the individual metabolic rate, whether measured before or during fasting. Since fasting did not obliterate or reduce the individual differences in metabolic rate, it was possible to predict the individual duration of survival from knowledge of the prefasting metabolic rate. The total proportionate weight loss, which also influenced the survival time in fasting, was altered by changes in the environmental temperature and probably by other factors. The previous diet whether high in protein, fat or carbohydrate had little effect on the duration of survival. Fasting caused a decrease in the metabolic rate of intact rats at 22°C but no change in that of thyroidectomized rats or of rats living in the cold.

PERMISSIVE ROLE OF l-THYROXINE IN INDUCTION OF PANCREATIC AMYLASE BY CORTISOL IN NEONATAL RATS

1980 ◽  
Vol 86 (3) ◽  
pp. 497-500 ◽  
Author(s):  
MASAYOSHI KUMEGAWA ◽  
NORIHIKO MAEDA ◽  
TOSHIHIKO YAJIMA ◽  
TAISHIN TAKUMA ◽  
EIKO IKEDA ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Amylase Activity ◽  
Daily Injection ◽  
Pancreatic Amylase ◽  
Neonatal Rats ◽  
Rat Pancreas ◽  
Developing Rat ◽  
Permissive Role ◽  
Intact Rats

The effect of l-thyroxine (T4) on amylase activity in the developing rat pancreas has been investigated. Administration of T4 (0·2 μg/g body wt) alone to intact rats on days 5–10 after birth did not induce pancreatic amylase but the enzyme was induced significantly by daily injection of cortisol (10 μg/g body wt) alone into intact rats over the same period. In thyroidectomized, adrenalectomized rats pancreatic amylase was not induced by the injection of cortisol alone but it was induced by the administration of cortisol plus T4. Increase in enzyme activity was much less in thyroidectomized animals than in intact animals. These results suggested that T4 does not have a direct effect in increasing pancreatic amylase activity but plays a permissive role in increasing enzyme activity.

Effects of Aldosterone on Mitochondrial Enzyme(s) and Cytochromes of Rat Tissues

1972 ◽  
Vol 50 (11) ◽  
pp. 1219-1225 ◽  
Author(s):  
D. K. Liu ◽  
C. C. Liew ◽  
A. G. Gornall
Keyword(s):  
Body Weight ◽  
Enzyme Activity ◽  
Actinomycin D ◽  
Citrate Synthase ◽  
Enzyme System ◽  
Rat Tissues ◽  
Mitochondrial Enzymes ◽  
Mitochondrial Enzyme ◽  
Adrenalectomized Rats ◽  
Stimulation Of

The activities of the kidney mitochondrial enzymes citrate synthase, NAD–isocitrate dehydrogenase, and α-ketoglutarate dehydrogenase, and the levels of cytochromes a + a3 and b were decreased following adrenalectomy. These decreases in enzyme activity and cytochrome levels could be restored by the administration of 5 μg of aldosterone per 100 g body weight. The effects of adrenalectomy and aldosterone administration were not observed in mitochondria from rat heart or liver. It was also found that giving 250 μg of corticosterone per 100 g body weight to adrenalectomized animals did not restore kidney citrate synthase activity. Neither actinomycin D nor puromycin, when given to adrenalectomized rats prior to aldosterone administration, inhibited the stimulation of citrate synthase activity or the levels of cytochromes a + a3 and b. It is concluded that the effect of aldosterone on the oxidative enzyme system is not the result of its stimulation of transcription or translation mechanisms.

Calmodulin dependency of calcitonin action on glucose-6-phosphatase and phosphorylase a activites in the liver of rats

1983 ◽  
Vol 104 (4) ◽  
pp. 490-494 ◽  
Author(s):  
Masayoshi Yamaguchi ◽  
Kaoru Momose
Keyword(s):  
Body Weight ◽  
Enzyme Activity ◽  
Phosphatase Activity ◽  
Calcium Ion ◽  
Calcium Content ◽  
Hepatic Glycogen ◽  
Maximal Effect ◽  
Hepatic Microsomes ◽  
Glycogen Particles ◽  
Intact Rats

Abstract. The calmodulin dependency of calcitonin (CT) action on glucose-6-phosphatase and phosphyrylase a activities in the liver of rats was investigated. A single sc administration of CT (synthetic [A1,7] eel CT; 80 MRC mU/100 g body weight) produced significant increases in calcium content and glucose-6-phosphatase activity in the hepatic microsomes of intact and thyroparathyroidectomized rats. These increases in enzyme activity were significantly inhibited by W-7 (100 μm), with a concentration which showed maximal effect. However, this inhibition was less than 50% of the enzyme activity increased by CT administration. Meanwhile, CT produced significant increases in calcium content and phosphorylase a activity in the hepatic glycogen particles from intact rats. However, this increase in enzyme activity was not influenced significantly by W-7 (100 μm), suggesting that the calcium ion may directly activate the enzyme. These results suggest that the increase in microsomal glucose-6-phosphatase activity of rat liver mediated by cellular calcium following CT administration may partly depend on calmodulin.

THE EFFECT OF THYROID ADMINISTRATION ON THE PANCREATIC AMYLASE ACTIVITY OF HYPOPHYSECTOMIZED AND INTACT RATS

1963 ◽  
Vol 41 (1) ◽  
pp. 1373-1379 ◽  
Author(s):  
Madelaine O. Maykut ◽  
Margaret T. Nishikawara ◽  
R. E. Haist
Keyword(s):  
Body Weight ◽  
Thyroid Gland ◽  
Amylase Activity ◽  
Total Activity ◽  
Pancreatic Amylase ◽  
Hypophysectomized Rats ◽  
Dose Levels ◽  
Marked Atrophy ◽  
Intact Rats

The administration of desiccated thyroid gland to hypophysectomized rats prevented the marked atrophy of the pancreas which was consistently observed following hypophysectomy. Thyroid feeding at two dose levels led to a significant increase in the pancreatic amylase activity of hypophysectomized rats. This held whether the results were expressed as total activity or were given as activity per unit of body weight, per unit of pancreas, or per mg nitrogen. Except for the activity per unit of body weight, the amylase activity of the thyroid-treated hypophysectomized rats was significantly lower than the amylase activity in untreated, intact controls. In the thyroid-fed, hypophysectomized rats the amylase activity per unit of body weight was not significantly different from that of intact, untreated controls.Thyroid administration in intact rats resulted in a decrease in the pancreatic amylase activity.

Suppression of pituitary-testis function in rats treated neonatally with a gonadotrophin-releasing hormone agonist and antagonist: acute and long-term effects

1989 ◽  
Vol 123 (1) ◽  
pp. 83-91 ◽  
Author(s):  
K.-L. Kolho ◽  
I. Huhtaniemi
Keyword(s):  
Body Weight ◽  
Gnrh Agonist ◽  
Gnrh Antagonist ◽  
Long Term Effects ◽  
Adult Rats ◽  
Releasing Hormone ◽  
Serum Lh ◽  
Accessory Sex Organs ◽  
Gonadotrophin Releasing Hormone

ABSTRACT The acute and long-term effects of pituitary-testis suppression with a gonadotrophin-releasing hormone (GnRH) agonist, d-Ser(But)6des-Gly10-GnRH N-ethylamide (buserelin; 0·02, 0·1, 1·0 or 10 mg/kg body weight per day s.c.) or antagonist, N-Ac-d-Nal(2)1,d-p-Cl-Phe2,d-Trp3,d-hArg(Et2)6,d-Ala10-GnRH (RS 68439; 2 mg/kg body weight per day s.c.) were studied in male rats treated on days 1–15 of life. The animals were killed on day 16 (acute effects) or as adults (130–160 days; long-term effects). Acutely, the lowest dose of the agonist decreased pituitary FSH content and testicular LH receptors, but with increasing doses pituitary and serum LH concentrations, intratesticular testosterone content and weights of testes were also suppressed (P< 0·05–0·01). No decrease was found in serum FSH or in weights of accessory sex organs even with the highest dose of the agonist, the latter finding indicating continuing secretion of androgens. The GnRH antagonist treatment suppressed pituitary LH and FSH contents and serum LH (P< 0·05–0·01) but, as with the agonist, serum FSH remained unaltered. Testicular testosterone and testis weights were decreased (P <0·01) but testicular LH receptors remained unchanged. Moreover, the seminal vesicle and ventral prostate weights were reduced, in contrast to the effects of the agonists. Pituitary LH and FSH contents had recovered in all adult rats treated neonatally with agonist and there was no effect on serum LH and testosterone concentrations or on fertility. In contrast, in adult rats treated neonatally with antagonist, weights of testis and accessory sex organs remained decreased (P <0·01–0·05) but hormone secretion from the pituitary and testis had returned to normal except that serum FSH was increased by 80% (P <0·01). Interestingly, 90% of the antagonist-treated animals were infertile. It is concluded that treatment with a GnRH agonist during the neonatal period does not have a chronic effect on pituitary-gonadal function. In contrast, GnRH antagonist treatment neonatally permanently inhibits the development of the testis and accessory sex organs and results in infertility. Interestingly, despite the decline of pituitary FSH neonatally, neither of the GnRH analogues was able to suppress serum FSH values and this differs from the concomitant changes in LH and from the effects of similar treatments in adult rats. Journal of Endocrinology (1989) 123, 83–91

Dissimilar Anxiety-like Behavior in Prepubertal and Young Adult Female Rats on Acute Exposure to Aluminium

2021 ◽  
Vol 22 ◽  
Author(s):  
Trina Sengupta ◽  
Sutirtha Ghosh ◽  
Archana Gaur T. ◽  
Prasunpriya Nayak
Keyword(s):  
Body Weight ◽  
Young Adult ◽  
Adult Female ◽  
Developmental Stages ◽  
Elevated Plus Maze ◽  
Age Groups ◽  
Female Rats ◽  
Acute Exposure ◽  
Adult Rats ◽  
Plus Maze

Background: Puberty is a developmental transition in which an estrogenic surge occurs, mediating the release of xenoestrogens, like aluminium. Aluminium’s effect on anxiety in rodents at the different developmental stages is inconsistent. Aims: This study aimed at investigating the effect of the metalloestrogenic property of aluminium on anxiety-like behavioral changes in prepubertal and young adult female rats. Objective: Considering this aim, our objective was to evaluate the anxiety-like behavior by the elevated plus maze in prepubertal and young adult female rats with or without acute exposure to aluminium. Methods: To address this property of aluminium, 5mg/Kg body weight (Al-5) and 10 mg/Kg body weight (Al-10) of aluminium was administered intraperitoneally to female rats at two developmental stages, prepubertal (PP; n = 8 for each dose) and young adult (YA; n = 6 for each dose) for two weeks. Post-treatment, three days behavioral assessment of the rats was done employing elevated plus maze. Results: Reduced escape latency was seen in Al-5, Al-10 pre-pubertal rats, and Al-5 young-adult rats on day 3. A significant reduction in open arm time was seen in the Al-5 young-adult rats. Aluminium treatment in the pre-pubertal rats reduced their head dipping and grooming. Reduced sniffing, head dipping, and stretch-attended posture in the treated young-adult female rats showed that they had impaired risk-taking tendency. Conclusion: Differential effect on the anxiety-like behavior in the pre-pubertal and young-adult female rats might be due to the metalloestrogenic property of aluminium, acting differently on the two age groups.

Sign in / Sign up

Export Citation Format

Share Document