Adrenal cortex

About: Adrenal cortex is a research topic. Over the lifetime, 8886 publications have been published within this topic receiving 232746 citations.

Stress hormones: Their interaction and regulation.

Abstract: Stress stimulates several adaptive hormonal responses. Prominent among these responses are the secretion of catecholamines from the adrenal medulla, corticosteroids from the adrenal cortex, and adrenocorticotropin from the anterior pituitary. A number of complex interactions are involved in the regulation of these hormones. Glucocorticoids regulate catecholamine biosynthesis in the adrenal medulla and catecholamines stimulate adrenocorticotropin release from the anterior pituitary. In addition, other hormones, including corticotropin-releasing factor, vasoactive intestinal peptide, and arginine vasopressin stimulate while the corticosteroids and somatostatin inhibit adrenocorticotropin secretion. Together these agents appear to determine the complex physiologic responses to a variety of stressors.

Congenital adrenal hyperplasia

Abstract: Congenital adrenal hyperplasia is a group of autosomal recessive disorders resulting from the deficiency of one of the enzymes required for cortisol synthesis in the adrenal cortex. The most freque...

The adrenal cortex.

Abstract: is "friction, obstruction and the defeat of most attempts at improved control". Sometimes the less pecunious neighbour, in its determinationto retain a valued rateable area, will bitterly resent and obstruct all attempts to transfer such portions of a town as lie within its own boundaries to the local authority controlling the major part of the urban area. Again, many of the roads boards covering extensive areas are but sparsely populated; in some instances great parts are quite uninhabited. In these instancesthe ratio of population to areamay be so low that even the highest possible rating will yield insufficient money for health purposes. The result has been that in theseareasthere has been a tendencyto use for 'road board administration money that has been collected as a health rate. This kind of arrangementcan only be describedas ridiculous. It is also pathetic. Dr. Cook states bluntly that education of the public in the principles of hygiene has been neglected. "This", he declares, "must be inevitable where the Local Authority is uninformed and where there is no technical adviser to impart the fundamentalsof knowledge by precept or by coercion." Government departments,he insists, set an example of tolerated neglect. Describing defects in the provision of privies, he states that conspicuous among thosewhich do not conform to local by-laws or to the first principles of sanitation are those of the Railway Commissioner, the Parks and Gardens Board, the Education Department,public hospitalsand local roads boardsthemselves. The astoundingstatementis madethat at 91 public schools the duty of night soil disposal is imposed upon the school teacheror the school children. At the outset the report issued by Dr. Cook was describedas a departmentaldirge. There are some bright spots in it, but the present need is to emphasize the unsatisfactorybasis on which much of the public health work has to be attempted. A year or two ago it was urged that a Royal Commissionshould be set up to survey the public health needs of Western Australia and to suggestways in which those needs could be met. This has not been done. If a commission is merely to take evidencewhich will be put on one side, as sooften happens, it would be better not to waste money on the effort. If the governmentwould consider the setting up of a new framework to replace the presentroads board patchwork, the step would be worth while. If nothing is done in the next few months perhaps some public spirited member of the medical profession will presentat the congressin Perth next August a pap"erwhich can be usedas a weapon to arousepublic interestand indignation.

Molecular Determinants of Glucocorticoid Receptor Function and Tissue Sensitivity to Glucocorticoids

Abstract: I. Introduction STEROID hormones are essential constituents of the intercellular communication system that maintains homeostasis in higher organisms. Glucocorticoids, a major subclass of steroid hormones, modulate a large number of metabolic, cardiovascular, immune, and behavioral functions (for a review see Refs. 1 and 2). Glucocorticoids are produced by the adrenal cortex under the regulatory influence of ACTH. The latter is produced by corticotrophs of the anterior pituitary, in turn, under the regulatory influence of hypothalamic CRH and arginine vasopressin (AVP). The hypothalamic-pituitary-adrenal (HPA) axis is kept in balance by the negative feedback effects of cortisol on the secretion of ACTH, CRH, and usually, to a lesser extent, AVP. In the resting state, basal levels of CRH, AVP, ACTH, and cortisol are released in a pulsatile and circadian fashion. At these baseline levels, the main function of cortisol is to sustain normoglycemia and to prevent arterial hypotension. Whether and to what extent...

Early environmental regulation of forebrain glucocorticoid receptor gene expression: implications for adrenocortical responses to stress.

Abstract: The adrenal glucocorticoids and catecholamines comprise a frontline of defense for mammalian species under conditions which threaten homeostasis (conditions commonly referred to as stress). Glucocorticoids represent the end product of the hypothalamic-pituitary-adrenal (HPA) axis and along with the catecholamines serve to mobilize the production and distribution of energy substrates during stress. The increased secretion of pituitary-adrenal hormones in response to stress is stimulated by the release of corticotropin-releasing hormone (CRH) and/or arginine vasopressin (AVP) from neurons in the nucleus paraventricularis. In this way, a neural signal associated with the stressor is transduced into a set of endocrine and sympathetic responses. The development of the HPA response to stressful stimuli is altered by early environmental events. Animals exposed to short periods of infantile stimulation or handling show decreased HPA responsivity to stress, whereas maternal separation, physical trauma and endotoxin administration enhance HPA responsivity to stress. In all cases, these effects persist throughout the life of the animal and are accompanied by increased hypothalamic levels of the mRNAs for CRH and often AVP. The inhibitory regulation of the synthesis for these ACTH releasing factors is achieved, in part, through a negative feedback loop whereby circulating glucocorticoids act at various neural sites to decrease CRH and AVP gene expression. Such inhibitory effects are initiated via an interaction between the adrenal steroid and an intracellular receptor (either the mineralocorticoid or glucocorticoid receptor). We have found that these early environmental manipulations regulate glucocorticoid receptor gene expression in the hippocampus and frontal cortex, regions that have been strongly implicated as sites for negative-feedback regulation of CRH and AVP synthesis. When the differences in glucocorticoid receptor density are transiently reversed, so too are those in HPA responses to stress. Taken together, our findings indicate that the early postnatal environment alters the differentiation of hippocampal neurons. This effect involves an altered rate of glucocorticoid receptor gene expression, resulting in changes in the sensitivity of the system to the inhibitory effects of glucocorticoids on the synthesis of CRH and AVP in hypothalamic neurons. Changes in CRH and AVP levels, in turn, determine the responsivity of the axis to subsequent stressors; increased releasing factor production is associated with increased HPA responses to stress. Thus, the early environment can contribute substantially to the development of stable individual differences in HPA responsivity to stressful stimuli. These data provide examples of early environmental programming of neural systems. One major objective of our research is to understand how such programming occurs within the brain.