Effects of ovariectomy on the oxidative metabolism of the central nervous system and adrenal glands in female hamster (Mesocricetus auratus)

Summary We have studied the influence of ovariectomy on the oxidative activity of hypophysis, hypothalamus, posterior cortex, septal area, amygdala and adrenal glands, in female hamsters, because their neuroendocrine behavior seems to differ from that of rats. Our results show a decreasing the O₂ uptake in the hypothalamus and adrenal glands and an increase in the rest of the structures.     

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.     

An update on the biology and physiology of resistin

Resistin is a newly discovered adipocyte hormone. It is related to resistin-like molecules alpha, beta and gamma in structure and function. Resistin is produced by white and brown adipose tissues but has also has been identified in several other tissues, including the hypothalamus, pituitary and adrenal glands, pancreas, gastrointestinal tract, myocytes, spleen, white blood cells and plasma. The tissue level of resistin is decreased by insulin, cytokines such as tumour necrosis factor alpha, endothelin-1 and increased by growth and gonadal hormones, hyperglycaemia, male gender and some proinflammatory cytokines, such as interleukin-6 and lipopolysaccharide. Resistin antagonizes insulin action, and it is downregulated by rosiglitazone and peroxisome proliferator-activated receptor gamma agonists. Since evidence of a direct link between resistin genotype and human diabetes is still weak, more molecular, physiological and clinical studies are needed to determine the role of resistin in the aetiology of type 2 diabetes.     

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).     

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 degrees 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 degrees 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.     

Tissue specificity of testosterone fixation: demonstrated by ultrastructural immunocytochemistry after cryoultramicrotomy]

Testosterone can be detected by immunocytochemistry on ultrathin slices obtained by cryoultramicrotomy. Testosterone detected by this method is likely bound on a binding site having a high affinity. In order to study the tissue specificity of this binding, testosterone was tested in Rat pituitary gland, liver and adrenal glands. Immunoreactive testosterone was detected in the gonadotropic cells of the pituitary gland, in the hepatocytes. Testosterone was not detected by immunocytochemistry in the pituitary cells other than the gonadotropic cells and in the cells of the medulla of adrenal glands. These data testify in favour of tissue specificity of the testosterone binding.     

Allotransplantation of rat parathyroid glands: effects of organ culture and transplantation into the adrenal gland.

Allotransplantation of fresh, 1 or 2 week cultured parathyroid glands from Wistar rats (AgB2) to Fischer rats (AgB1) resulted in prompt rejection of the transplant in the muscle site; whereas transplantation into the adrenal site offered slightly prolonged survival, suggesting that the latter is a privileged transplantation site.     

Effect of two insecticides, lindane and DDVP (dichlorvos) on mouse adrenal glands]

Poisoning of non-pregnant female mice by sublethal doses of Dichlorvos and gamma-BHC (Lindane) induces prominent adrenal alterations. A significant weight increase of the glands is observed while Norepinephrine and Epinephrine content is depleted after Dichlorvos intoxication.     

Bromocriptine and sulpiride competitively inhibit estrogen binding to its receptor in the adrenal gland

Bromocriptine and sulpiride incubated simultaneously with [3H]-estradiol in the cytosol from adrenal glands of adult male rats, yielded curves typical of competitive inhibition as analyzed by Lineweaver-Burk plots. The inhibition constant for both drugs was approximately 10(8) M-1, only 10 times lower than the association constant for estradiol.     

The responsiveness to (1-24) ACTH of Mongolian gerbil adrenals superfused in vitro as a function of basal secretion

Wide variations have been found in the responsiveness to (1-24)ACTH of Mongolian gerbil adrenal glands superfused in vitro. These variations were not correlated to corticosteroid plasma levels or to adrenal weights. In contrast, (1-24)ACTH-stimulated secretion greatly depended on basal in vitro secretion (quarters: r = 0.97, p less than 0.01; slices: r = 0.90, p less than 0.001) indicating that the fine adjustment of basal corticosteroidogenesis forms an important part of the regulatory mechanisms modulating (1-24)ACTH-stimulated corticosteroid secretion in vitro.     

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.     

Effect of adrenalectomy on sound-induced seizure susceptibility and intensity in genetically susceptible rats

Summary Neither seizure susceptibility nor intensity was altered by sham-operation or by adrenalectomy in adult rats that are genetically susceptible to sound-induced seizures. Thus, sound-induced seizures in genetically susceptible rats are analogous to those in genetically susceptible mice to the extent that removal of the adrenal glands does not alter established seizure characteristics in either species.     

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.     

Catecholamine metabolism in the vas deferens and the adrenal gland with special reference to the central catecholamine-depleted state.

Experiments were carried out to elucidate the role of central catecholamines in regulating catecholamine metabolism in the vas deferens and adrenal gland of the rat. Rats were injected intracerebroventricularly (i.c.v.) with either vehicle or 6-hydroxydopamine (6-OHDA). Groups of animals pretreated with vehicle or 6-OHDA (i.c.v.) were injected intraperitoneally (i.p.) with alpha-methyl-para-tyrosine (AMT), a tyrosine hydroxylase inhibitor. Catecholamine turnover rates were estimated by determining norepinephrine or epinephrine content after administering AMT. Central norepinephrine and dopamine contents decreased significantly (p less than 0.05) after treatment with 6-OHDA and AMT. The norepinephrine content of the vas deferens of rats pretreated with 6-OHDA was markedly reduced (p less than 0.001) after administration of AMT, whereas that of the vehicle-treated rats remained unchanged. Administration of 6-OHDA had no effect on the norepinephrine or epinephrine content of the adrenal gland. The present results indicate that central monoaminergic neurons have an inhibitory effect on the adrenergic neurons of the vas deferens. In contrast, this inhibitory regulation does not appear to be exerted on the adrenal glands.     

Catecholamine metabolism in the vas deferens and the adrenal gland with special reference to the central catecholamine-depleted state

Experiments were carried out to elucidate the role of central catecholamines in regulating catecholamine metabolism in the vas deferens and adrenal gland of the rat. Rats were injected intracerebroventricularly (i.c.v.) with either vehicle or 6-hydroxydopamine (6-OHDA). Groups of animals pretreated with vehicle or 6-OHDA (i.c.v.) were injected intraperitoneally (i.p.) with alpha-methyl-para-tyrosine (AMT), a tyrosine hydroxylase inhibitor. Catecholamine turnover rates were estimated by determining norepinephrine or epinephrine content after administrating AMT.Central norepinephrine and dopamine contents decreased significantly (p<0.05) after treatment with 6-OHDA and AMT. The norepinephrine content of the vas deferens of rats pretreated with 6-OHDA was markedly reduced (p<0.001) after administration of AMT, whereas that of the vehicle-treated rats remained unchanged. Administration of 6-OHDA had no effect on the norepinephrine or epinephrine content of the adrenal gland.The present results indicate that central monoaminergic neurons have an inhibitory effect on the adrenergic neurons of the vas deferens. In contrast, this inhibitory regulation does not appear to be exerted on the adrenal glands.     

Allotransplantation of rat parathyroid glands: Effects of organ culture and transplantation into the adrenal gland

Summary Allotransplantation of fresh, 1 or 2 week cultured parathyroid glands from Wistar rats (AgB²) to Fischer rats (AgB¹) resulted in prompt rejection of the transplant in the muscle site; whereas transplantation into the adrenal site offered slightly prolonged survival, suggesting that the latter is a privileged transplantation site.Acknowledgments. The authors thank Mrs Barbara Lovett for her secretarial assistance.     

Au sujet de la mesure des modifications de l'adrénalino-sécrétion

Summary A method is described that allows blood samples to be taken repeatedly from the suprarenal vein, without changing the circulation in the adrenal glands or eliciting reflexes which could interfere with the adrenalin secretion. The vasoconstrictor properties of the blood samples are tested on an isolated blood vessel preparation.     

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

Summary 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.Lüthy, I. A., Predoctoral Fellow from the Consejo Nacional de Investigaciones Cientificas y Técnicas and Calandra, R. S., Research Career Awardee from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.Acknowledgments. We would like to thank Mrs D. Bas and Mrs D. B. Destéfano for the skillful technical assistance and the secretarial work, respectively. This work was partially supported by the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET), and the Comisión Nacional de Energía Atómica.     

Correlation between serum dopamine-beta-hydroxylase activity and dopamine-beta-hydroxylase and tyrosine hydroxylase activities in central and peripheral adrenergic neurons and adrenal glands.

Serum dopamine-beta-hydroxylase activity in spontaneously hypertensive rats and Wistar-Kyoto rats had a positive correlation with dopamine-beta-hydroxylase and tyrosine hydroxylase activities in mesenteric vessels, vas deferens, and adrenal glands at 14-16 weeks of age, a negative correlation with dopamine-beta-hydroxylase activity in locus coeruleus at 3 weeks and 14-16 weeks of age, and a positive correlation with tyrosine hydroxylase activity only at 3 weeks of age, but not at 14-16 weeks of age.     

Hemmung der Corticosteroid-11Β-hydroxylierung durch einen Extrakt aus corpus pineale

Summary A hexane extract of bovine pineal glands reduced the production of 11-OH-corticosteroids and augmented the formation of 11-desoxycorticosteroids in slices of bovine adrenal cortex. It is suggested, therefore, that bovine pineal glands contain one or several substances which inhibit the 11-hydroxylation of corticosteroids.