<i>In Vitro</i>Effects of ACTH, Angíotensíns, Serotonin and Potassium on Steroid Output and Conversion of Corticosterone to Aldosterone by Isolated Adrenal Cells

Abstract

Adrenal cells have been prepared, using crude collagenase, from the separated capsular and decapsulated portions of adrenals from intact rats. Microscopic examination and consideration of steroid outputs suggest that preparations from decapsulated glands consist of zona fasciculata-reticularis cells, while those from capsular glands consist mainly of zona glomerulosa cells with some zona fasciculata contamination. The yield of cells from the 2 preparations was of the order of 2 ×105 cells/adrenal for decapsulated glands and 1 ×lO5/adrenal for capsular glands. The endogenous output of 18-OH B, aldosterone, 18-OH DOC and corticosterone from the incubations of capsular and decapsulated gland cells has been examined. Three of the 4 steroids are produced by both types of cells; aldosterone production is virtually confined to capsular gland cells. The effect of ACTH, angiotensins, potassium and serotonin added in vitro on the output of corticosterone by decapsulated gland cells and that of corticosterone and aldosterone by capsular gland cells has been examined. ACTH increased the output of corticosterone by decapsulated gland cells over a range of 0.16–2.56 mU/ml to a maximum of 40 times the incubated control value. Corticosterone and aldosterone outputs by capsular gland cells increased over the same range but only to 3–4 and 5–6 times the control value, respectively. By contrast, serotonin (lO−8–10−4M) and potassium (3.6–13 HIM) had no effect on corticosterone output by decapsulated gland cells but consistently increased the outputs of corticosterone and aldosterone by capsular gland cells, although to a lesser extent than did ACTH. With all 3 stimuli the relative increase in aldosterone output by capsular gland cells exceeded that of corticosterone, suggesting a stimulatory effect on the conversion of corticosterone to aldosterone. This was seemingly confirmed by direct measurement of the conversion of 3H-corticosterone to 3H-aldosterone. However, this radioactive conversion is correlated with non-isotopic corticosterone output and addition of corticosterone to the supernatant will increase it. The mechanism of this effect remains to be elucidated. Angiotensins (valine-5-and isoleucine-5) have a relatively small effect on corticosterone and aldosterone output and the corticosterone to aldosterone conversion with both 5.6 and 3.6 HIM potassium in the incubation medium. (Endocrinology87: 1147, 1970)