Regulation of mineralocorticoid Secretion

The regulation of mineralocorticoid secretion is therefore deeply intertwined with the regulation of humor electrolyte concentrations, humor volume, blood volume, blood pressure, and lots of special aspects of nephritic perform that it’s tough to debate the regulation of mineralocorticoid secretion severally of of these alternative factors.However, it’s necessary to list here a number of the additional details of mineralocorticoid secretion control. The regulation of mineralocorticoid secretion by the structure glomerulosa cells is sort of entirely freelance of the regulation of adrenal cortical steroid and androgens by the structure fasciculata and structure reticularis. Four factors square measure known to play essential roles within the regulation of mineralocorticoid. within the probable order of their importance, they’re as follows: one. exaggerated K particle concentration within the extracellular fluid greatly will increase mineralocorticoid secretion.

1. exaggerated activity of the renin-angiotensin system (increased levels of vasoconstrictor II) additionally greatly increases mineralocorticoid secretion.

2. exaggerated Na particle concentration within the extracellular fluid terribly slightly decreases aldosterone secretion.

3. adrenocorticotropin from the secreter|adenohypophysis|endocrine gland|endocrine|ductless gland} gland is necessary for mineralocorticoid secretion however has very little effect in dominant the speed of secretion.

Of these factors, K particle concentration and the renin-angiotensin system square measure far and away the foremost potent in control mineralocorticoid secretion. A small percentage increase in K concentration will cause a severalfold increase in mineralocorticoid secretion. Likewise, activation of the renin-angiotensin system, usually in response to diminished blood flow to the kidneys or to Na loss, will cause a severalfold increase in mineralocorticoid secretion. In turn, the mineralocorticoid acts on the kidneys (1) to assist them pass the excess K ions and (2) to extend the blood volume and blood pressure, so returning the reninangiotensin system toward its traditional level of activity. These feedback management mechanisms square measure essential for maintaining life. Figure shows the results on plasma mineralocorticoid concentration caused by obstruction the formation of angiotensin II with AN angiotensin-converting accelerator inhibitor when many weeks of a low-salt diet that increases plasma mineralocorticoid concentration severalfold. Note that obstruction angiotonin formation markedly decreases plasma mineralocorticoid concentration without considerably dynamical adrenal cortical steroid concentration; this indicates the necessary role of angiotonin in stimulating mineralocorticoid secretion once Na intake and humor volume square measure reduced.

By distinction, the results of Na particle concentration per se and of adrenocorticotropin in dominant mineralocorticoid secretion square measure sometimes minor. notwithstanding, a ten to twenty per cent decrease in humor Na particle concentration, that happens on rare occasions, will maybe double mineralocorticoid secretion. within the case of adrenocorticotropin, if there is even atiny low quantity of adrenocorticotropin secreted by the anterior pituitary secretory organ, it’s sometimes enough to allow the adrenal glands to secrete no matter quantity of aldosterone is needed, however total absence of adrenocorticotropin can considerably scale back mineralocorticoid secretion.

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