Modification by Su-10'603 of the response to histamine on the production of cortisol and corticosterone in isolated canine adrenocortical cells

Effect of platelet-activating factor on cortisol and corticosterone secretion by perfused dog adrenal

Administration of platelet-activating factor (PAF) to perfused adrenal increased cortisol and corticosterone secretion. With hexadecyl PAF (C16PAF; 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine), the increase was significant at 1 nM and maximal at 10 nM. The responses to 10 nM octadecyl PAF (C18PAF; 1-O-octadecyl-2-acetyl-sn-glycero-3-phosphocholine) were one fourth of those to 10 nM C16PAF. The addition of C16PAF to dispersed adrenal cells significantly increased cortisol and corticosterone production at 0.1 nM and 10 nM, respectively. C16PAF was about 1000 times more potent than histamine on a molar basis in respect to cortisol response in both perfused adrenal and dispersed adrenal cells. The results suggest that PAF induces cortisol release from dog adrenal.

H1 action of histamine on aldosterone and cortisol secretion by perfused dog adrenal

The left adrenal of hypophysectomized-nephrectomized dogs was perfused in situ with artificial medium equilibrated with 95% O2-5% CO2. Repeated secretory responses of aldosterone to ACTH and histamine were almost reproducible during 2 h of perfusion, but those of cortisol and corticosterone gradually reduced. The secretion of aldosterone in response to histamine markedly increased at 1 microM and those of cortisol and corticosterone significantly increased at 1 and 10 microM, respectively. The secretory response of aldosterone to 10 microM histamine was comparable with that to 300 microU/ml ACTH, but the secretory responses of cortisol and corticosterone to 10 microM histamine were very much lower than those to 1 microU/ml ACTH. The secretory responses of these three steroids to 10 microM histamine were almost completely depressed by continuous administration of 10 microM pyrilamine maleate, but not abolished by that of 100 microM metiamide. The secretory responses of these three steroids to 10 microM histamine were slightly depressed by continuous infusion of 10 microM methysergide maleate. These results suggest that histamine at pathophysiological concentrations stimulates the secretion of aldosterone markedly, and those of cortisol and corticosterone slightly, via an H1 receptor of adrenocortical cells in the dog.