Regulation of rat renal (Na++K+)-adenosine triphosphatase mRNA levels by corticosterone

We investigated the mechanisms for glucocorticoid regulation of rat renal NaK-ATPase activity. Our findings suggest that the magnitudes of corticosterone-induced increases in ₁ mRNA and ₁ mRNA levels are similar in the kidney of the adult adrenalectomized rats. The results also suggest that corticosterone restores NaK-ATPase activity in adrenalectomized rats prior to any enhanced sodium delivery.     

Effect of aldosterone and methylprednisolone on cardiac NaK-ATPase.

Aldosterone (15 microgram BID) and methylprednisolone (8 mg QD) administration to female guinea-pigs augmented both the total and the specific activity of NaK-ATPase but not the activity of adenylate cyclase in the cardiac sarcolemma. The rise in NaK-ATPase was due to increase in the number of enzyme molecules; catalytic activity and ouabain-sensitivity of individual molecules did not change.     

Effect of aldosterone and methylprednisolone on cardiac NaK-ATPase

Summary Aldosterone (15 g BID) and methylprednisolone (8 mg QD) administration to female guinea-pigs augmented both the total and the specific activity of NaK-ATPase but not the activity of adenylate cyclase in the cardiac sarcolemma. The rise in NaK-ATPase was due to increase in the number of enzyme molecules; catalytic activity and ouabain-sensitivity of individual molecules did not change.Acknowledgments. This work was supported by grant 1 R01 HL16611 from the National Heart and Lung Institute of the National Institutes of Health, United States Public Health Service. I thank Mr Kooil Kang for his excellent technical assistance.     

Acute changes in dopamine metabolism in the medio-basal hypothalamus following adrenalectomy

During the first hour following adrenalectomy the alpha-MPT-induced disappearance of dopamine was increased in the arcuate nucleus compared to that in sham-operated rats. In a number of other brain regions of both adrenalectomized and sham-adrenalectomized rats only stress-induced changes were observed in catecholamine utilization. These data suggest that corticosterone selectively modulates dopamine utilization in the medio-basal hypothalamus.     

Age-related response of citrate synthase to hydrocortisone in the liver and brain of male rats

The activity of citrate synthase of the liver and brain of rats shows a gradual increase as a function of age. Adrenalectomy causes no significant change in the activity of citrate synthase in either of these tissues in young, adult or old rats. Administration of hydrocortisone to adrenalectomized rats depresses the activity of this enzyme maximally in the liver and brain of young rats. Administration of actinomycin D tends to normalize the depressed level of this enzyme.     

Effect of adrenalectomy and dexamethasone treatment on the monoamine oxidase activity in the thyroid gland of the rat

Summary Adrenalectomy increased MAO activity in the thyroid gland of rats. The administration (200 g/100 g daily for 7 days) to adrenalectomized rats decreased MAO activity below levels of intact controls.     

Dietary induced increase of lactase activity in adult rats is independent of adrenals

Adult rats fed 10 days a low starch-high fat diet were either adrenalectomized or sham-operated and force-fed the same diet another 5 days; 14 h before sacrifice, some animals were force-fed a sucrose diet. Activity of lactase, sucrase and maltase was increased in adrenalectomized and sham-operated rats.     

Age-related response of citrate synthase to hydrocortisone in the liver and brain of male rats

Summary The activity of citrate synthase of the liver and brain of rats shows a gradual increase as a function of age. Adrenalectomy causes no significant change in the activity of citrate synthase in either of these tissues in young, adult or old rats. Administration of hydrocortisone to adrenalectomized rats depresses the activity of this enzyme maximally in the liver and brain of young rats. Administration of actinomycin D tends to normalize, the depressed level of this enzyme.Acknowledgments. The authors are indebted to Professor M.S. Kanungo of the Department of Zoology of Banaras Hindu University for helpful advice and facilities. A part of this project was presented at the 12th International Congress of Biochemistry, Australia, 1982.     

Dietary induced increase of lactase activity in adult rats is independent of adrenals

Summary Adult rats fed 10 days a low starch-high fat diet were either adrenalectomized or sham-operated and force-fed the same diet another 5 days; 14 h before sacrifice, some animals were force-fed a sucrose diet. Activity of lactase, sucrase and maltase was increased in adrenalectomized and sham-operated rats.Supported by the National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA (AM 27624).     

Acute changes in dopamine metabolism in the medio-basal hypothalamus following adrenalectomy

Summary During the first hour following adrenalectomy the -MPT-induced disappearance of dopamine was increased in the arcuate nucleus compared to that in sham-operated rats. In a number of other brain regions of both adrenalectomized and sham-adrenalectomized rats only stress-induced changes were observed in catecholamine utilization. These data suggest that corticosterone selectively modulates dopamine utilization in the medio-basal hypothalamus.Acknowledgment. The skilful technical assistance of Ms Joke Van Put, Ms Henny De Vos Burchart-Lodewijks and Mr Henk Spierenburg is gratefully acknowledged.     

Relationship between the renal kallikrein activity and the urinary excretion of kallikrein in rats

Summary Adrenalectomy reduces, and sodium depletion increases, both the daily urinary excretion of kallikrein and the kallikrein activity in the renal cortex. These 2 variables were found to correlate significantly in normal, sodium depleted and adrenalectomized rats, thus supporting the view that kallikrein excretion reflects the activity of the enzyme in the kidney.Acknowledgments. This word was supported by the Deutsche Forschungsgemeinschaft. The technical assistance of Mrs G. Breypohl and Ms J. Kopatsch is gratefully acknowledged. Dr M. Marin-Grez was a fellow of the Alexander von Humbodt Foundation and Dr G. Bönner of the Deutsche Forschungsgemeinschaft.     

Effect of bilateral adrenalectomy and parenteral betamethasone on gastric mucosal mast cell population in albino rats

Summary The histamine-laden mast cells gastric mucosa in albino rats are shown to degranulate on administration of Betamethasone, but they increase in number in adrenalectomized rats. It is concluded that Betamethasone, and also adrenal glucocorticoids incrase gastric secretion by liberating histamine from mast cells and histamine in turn acts on the gastric glands.     

Adrenalectomy,ovarian HCG-binding and the onset of female puberty in the rat

Summary The delay of puberty onset in female rats adrenalectomized before the 25th day of age is due neither to changes in the number of ovarian HCG-receptors nor to an altered hormone affinity of these receptors. It is assumed that glucocorticoids act on an intracellular level, in the ovarian cells, possibly by alterations of cyclic AMP-dependent phosphodiesterase activity.This work was supported in part by the Deutsche Forschungsgemeinschaft (SFB 46). Purified HCG was a gift of Schering AG, Berlin-West. We thank Mrs Margarete Lindig for assistance and Mrs Ursula Frigewski for secretarial help.     

Effect of bilateral adrenalectomy and parenteral betamethasone on gastric mucosal mast cell population in albino rats.

The histamine-laden mast cells of gastric mucosa in albino rats are shown to degranulate on administration of Betamethasone, but they increase in number in adrenalectomized rats. It is concluded that Betamethasone, and also adrenal glucocorticoids increase gastric secretion by liberating histamine from mast cells and histamine in turn acts on the gastric glands.     

Effect of pylorus ligation on gastric mucosal mast cell population in normal and adrenalectomised albino rats

Summary Pylorus ligation in normal albino rats acts like a stressor leading to degranulation of mast cells in gastric mucosa, thereby decreasing their number. This decrease is less pronounced when pylorus ligation is done in adrenalectomized rats. This implies that action of a stressor on gastric function involves the adrenal steroids which liberate the powerful gastric stimulant histamine from gastric mucosal mast cells.     

Effect of pylorus ligation on gastric mucosal mast cell population in normal and adrenalectomised albino rats.

Pylorus ligation in normal albino rats acts like a stressor leading to degranulation of mast cells in gastric mucosa, thereby decreasing their number. This decrease is less pronounced when pylorus ligation is done in adrenalectomized rats. This implies that action of a stressor on gastric function involves the adrenal steroids which liberate the powerful gastric stimulant histamine from gastric mucosal mast cells.     

Interaction between aldosterone and renomedullary prostaglandins. Competitive action between aspirin and spironolactone

Aldosterone injected i.m. decreased the release of renomedullary PGEs and the index (urinary Na/K ratio) in conscious normotensive intact and adrenalectomized rats. Coadministration of spironolactone increased the release of PGEs as well as the index (urinary Na/K ratio). The effect of spironolactone was partly inhibited by aspirin injected in a ratio 5:1 (aspirin:spironolactone), and effect which could be reversed by the infusion of a synthetic prostaglandin (PGA2) in a subhypotensive dose.     

Thrombozytose und Eosinophilie bei adrenalektomierten Ratten nach einmaliger 5-Hydroxytryptamininjektion

Summary In adrenalectomized rats, the injection of a single high dose of 5-hydroxytryptamin results, as in intact animals previously reported, in a strong increase of the number of platelets in the peripheral blood. The number of eosinophils, instead of decreasing, also rises. The maxima of increase are not in temporal accordance.     

Cholinesterase reactivators — Contribution to the study of their metabolic effects

Summary Cholinesterase reactivators — trimedoxim, methoxim and obidoxim — injected in the dose of 20 mg/kg s.c., increase muscle glycogen concentration in normal, but not in adrenalectomized rats. This effect may be in connection with simoultaneously found rise of serum corticosteron level. Trimedoxim decreases adrenaline, methoxim and obidoxim noradrenaline concentration in adrenals.     

Dissociation of glucocorticoid effects of C-21 steroids at high concentrations in thymocytes

A dissociation between inhibition of RNA synthesis and cell lysis was observed when thymocytes of adrenalectomized rats were incubated with high concentrations of pregn-4-ene-11 beta-ol-3,20-dione and pregna-1,4-diene-11 beta-ol-3,20-dione. In contrast, no dissociation of these effects was found with the typical glucocorticoids cortisol and corticosterone, nor with their 1,4-diene analogs under the same conditions.