Opposite effects of vasotocin injected intrapituitarly and intraventricularly on corticotropin release in mice.

A single injection of 10 pg synthetic arginine vasotocin into the pituitary significantly potentiated adrenal hypertrophy produced in male mice by unilateral adrenalectomy, whereas the same concentration injected into the 3rd ventricle produced adrenal atrophy.     

The function of miRNA in cardiac hypertrophy

Cardiac hypertrophy is an adaptive enlargement of the myocardium in response to altered stress or injury. The cellular responses of cardiomyocytes and non-cardiomyocytes to various signaling pathways should be tightly and delicately regulated to maintain cardiac homeostasis and prevent pathological cardiac hypertrophy. MicroRNAs (miRNAs) are endogenous, single-stranded, short non-coding RNAs that act as regulators of gene expression by promoting the degradation or inhibiting the translation of target mRNAs. Recent studies have revealed expression signatures of miRNAs associated with pathological cardiac hypertrophy and heart failure in humans and mouse models of heart diseases. Increasing evidence indicates that dysregulation of specific miRNAs could alter the cellular responses of cardiomyocytes and non-cardiomyocytes to specific signaling upon the pathological hemodynamic overload, leading to cardiac hypertrophy and heart failure. This review summarizes the cell-autonomous functions of cardiomyocyte miRNAs regulated by different pathways and the roles of non-cardiomyocyte miRNAs in cardiac hypertrophy. The therapeutic effects of a number of miRNAs in heart diseases are also discussed.     

Réaction immunoallergique provoquée chez le rat par l'injection d'extraits chauffés de la tumeur de Walker

Summary When repeatly injected to Fisher Inbred rats, boiled Walker tumour extracts induced non specific and specific reactions; non specific reactions being catabolism, thymus involution, adrenal hypertrophy and perturbation of serum proteins relative distribution. The specific reactions attributable to the presence of the specific tumoral antigen in the tumour extracts are immunoallergic arthritis, liver and spleen hypertrophy, acceleration of serum albumin electrophoretic migratory rate and the apparition of the specific antigen in the liver.

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Travail subventionné par l'Institut du Cancer du Canada.     

Effect of ACTH on the zona reticularis of the rat adrenal cortex: an ultrastructural stereologic study.

The effects of ACTH on the rat adrenal zona reticularis were investigated by stereologic methods. It was found that the zona reticularis cell responsiveness to ACTH is similar to that of the zona fasciculata elements. This excludes that the zona reticularis of the adult rat can only function as the site of destruction of worn-out elements migrating from the adrenal outer zones.     

Inhibition of steroidogenic activity in the adrenal cortex of rats fed benzene hexachloride (hexachlorocyclohexane)

Summary Feeding various dosages of benzene hexachloride (100, 250, 750 and 1500 ppm) in the diet to weanling male albino rats for 90 days resulted in marked hypertrophy of the adrenals with large, vacuolated cells in the cortex at 750 and 1500 ppm. Accumulation of cholesterol-positive lipids and marked reduction in the activities of steroidogenic enzymes such as ⁵ 3 HSDH, 11 HSDH, G-6-PDH and SDH were seen using histochemical methods in the adrenal cortex of rats fed 750 and 1500 ppm. The results are suggestive of steroidogenic inhibition at 750 and 1500 ppm of dietary BHC while 100 and 250 ppm did not produce any discernible changes in the adrenal cortex.Acknowledgments. The authors thank Dr Muralidhara, H.P. Ramesh and K. Nanjundiah for their help and Prof. H.B. Devaraj Sarkar, Department of Zoology, University of Mysore, for providing us facilities for histochemical work. We are grateful to Sri C.P. Natarajan, for his keen interest in this investigation.     

Adrenal responses to hypoxia and hypercapnia in the young calf

Summary Quantitative analysis of adrenal responses to moderate hypoxia and hypercapnia in the conscious calf shows that the sensitivity of the adrenal cortical response far exceeds that of the adrenal medulla.Acknowledgment. This work has been supported by grants from the Agricultural Research Council, the Medical Research Council and the Wellcome Trust. We are also indebted to Dr D. M. Burley (CIBA) for his continued support.     

Cellular changes of adrenal under the acute stress of O-chlorobenzylidene malononitrile (CS).

This investigation describes histological and cytometrical changes of cortical and medullary tissue of adrenal in rats under the acute stress of O-chlorobenzylidene malononitrile (10 mg/kg and 20 mg/kg). It has been observed that after injection of CS, the adrenal gland showed histological changes both in the cortical and medullary region.     

In vitro cAMP,aldosterone and cortisol responses of adult human adrenocortical tissue to ACTH and human growth hormone

Summary The acute in vitro effects of ACTH and HGH in human adrenals were examined. HGH acts synergistically with ACTH in augmenting adrenal aldosterone output. This effect is not due to cAMP alterations in response to HGH. HGH slightly depresses the human adrenal cortisol response to ACTH.     

Cellular changes of adrenal under the acute stress of O-chlorobenzylidene malononitrile (CS)

Summary This investigation describes histological and cytometrical changes of cortical and medullary tissue of adrenal in rats under the acute stress of O-chlorobenzylidene malononitrile (10 mg/kg and 20 mg/kg). It has been observed that after injection of CS, the adrenal gland showed histological changes both in the cortical and medullary region.The authors are thankful to Dr. P.K. Ramachandran, Director, Defence Research and Development Establishment, Gwalior, for his sustained interest and critical suggestions in the course of this study.     

Demonstration of high affinity binding of estradiol in adrenal cortex tissue]

Evidence is presented demonstrating the presence of a high affinity (Ka10(8)M-1), limited capacity (3-4 pmoles/mg protein) estradiol binder in the soluble fraction of the Bovine, Rat and Human adrenal cortex. The binding appears specific to the estrogen structure whereas C19 and C21 steroids do not bind. Upon sucrose density gradient centrifugation, the estradiol binder sedimented at 9 S at low ionic strength and was shifted to 4.5 S in the presence of 0.5 M KCl. This demonstration of a receptor-like moiety for estradiol in the adrenal cortex lends biochemical support to previous observations suggesting that adrenal cortex functions may be modulated by a direct effect of gonadal steroid hormones.     

Changes in the level of ACTH in the fetal hypophysis. A study in the rat toward the end of gestation]

The isolated adrenal cell method for bioassay of ACTH was employed in order to determine the ACTH content of the hypophysis of the rat foetus, in late pregnancy. The ACTH concentration decreases between 17 days 8 h and 17 days 15 h, then it increases regularly until the term. This evolution is correlated with the change in the fluorescence intensity of the corticotrophs and with the modification of the adrenocortical activity.     

A study on the effects of some drugs on DOCA induced hypertension in the rat

Summary Chronic treatment with various drugs reduced the increase in arterial blood pressure, the ventricular hypertrophy and the thickening of pulmonary arterial and arteriolar walls.This work was supported by the Italian CNR (contract No. 7901928.04 and 7902391.65).     

Ontogeny of the sex steroid and prolactin receptors in the male rat adrenal gland

Cytosolic estrogen and androgen receptors and membrane prolactin-binding sites in the male adrenal glands showed a definite pattern during sexual development. The level of sexual steroid receptors paralleled adrenal growth, whereas prolactin binding reached its maximum value in mature rats.     

Effect of stress on choline acetyltransferase activity of the brain and the adrenal of the rat

Choline acetyltransferase (ChAT) activity was determined in cerebral cortex, hypothalamus, hippocampus, cerebellum, medulla oblongata, midbrain and adrenal gland of rats exposed to acute or chronic stress. The exposure of animals to acute immobilization and cold stress (4°C) for one hour resulted in a significant decline of ChAT activity in all brain regions examined except for the medulla oblongata. Moreover, the exposure to acute stress resulted in significant increase of the same enzyme in the adrenal gland. However, chronic exposure of animals to cold stress (4°C) for 7 days resulted in no significant changes of ChAT activity in all tissues examined except for a decline in the midbrain and an increase in the medulla oblongata. The administration of corticosterone (2.0 mg/kg) 1 h prior to sacrificing caused an effect similar to that of acute stress on ChAT activity in all brain regions except for the hypothalamus and the cerebellum. It was concluded from this experiment that stress-induced changes in the ChAT activity of specific brain regions might be mediated by the adrenal steroids.This work was supported by a grant from the National Aeronautics and Space Administration (NSG 2183 and NAG 2-411), a grant from the National Institutes of Health (NIH RR 0811) and a grant from the Division of Research Resources (NIH grant RR 03020).     

Dopamine-beta-hydroxylase, adrenaline, noradrenaline and dopamine in the venous blood of adrenal gland of man: a comparison with levels in the periphery of the circulation.

In 10 human subjects plasma dopamine-beta-hydroxylase activity was found in the adrenal vein blood to be as high as in the periphery of the circulation. Adrenaline concentration in the adrenal vein blood was in the mean 170 times, noradrenaline concentration 11 times and dopamine concentration little higher than levels in the periphery.     

Cardiac hypertrophy in surgically denervated dogs with aortic stenosis

Summary Left ventricular cell hypertrophy in dogs with aortic stenosis was accelerated by surgical denervation of the left ventricle. We conclude that there are neural mechanisms which, when present, inhibit cardiac cell hypertrophy.This work was supported by a grant of the Ministry of Education in Japan for 1981.     

Stimulation by ACTH of protein synthesis in cultured adrenal cells. Absence of an effect by cyclin AMP]

ACTH stimulates the incorporation of 14C-leucine into proteins of adrenal tumor cells in culture. This stimulation though about 20% over controls is statistically significant. Cyclic AMP did not reproduce the stimulation observed with ACTH.