Production of Steroidsin Vivoby Regenerated Adrenal Glands of Hypertensive and Normotensive Rats

Publisher Website
Google Scholar
Abstract
Adrenal steroid secretion rates of pregnenolone, progesterone, deoxycorticosterone (DOC), 18-hydroxydeoxycorticosterone (18-OHDOC), and corticosterone (B) were measured in vivo under conditions of operative stress in unilaterally adrenalectomized and nephrectomized rats in which the left adrenal gland had been enucleated and the cortical tissue allowed to regenerate for 4-7 weeks. For comparison, rats which were only unilaterally adrenalectomized and nephrectomized (UAN) and sham operated controls were used. All rats received a 1% NaCl solution sweetened with 5% sucrose, instead of drinking water. One half of the adrenal-enucleated rats developed hypertension (ARH) with blood pressures ranging from 150-210 mm Hg, one half remained normotensive (AR), although the kidneys and hearts were enlarged to the same extent in both groups. The hypertrophy of the kidney was less marked in UAN rats than in AR or ARH rats. Control rats which had two adrenal glands secreted about 3 μg pregnenolone and progesterone per 100 g body wt per hour, approximately twice as much as the rats in all the other groups which had only one adrenal gland. The ARH rats secreted half the amount of DOC secreted by the AR or the control rats, but more than the UAN rats. The mean secretion of B and 18-0H-D0C in AR and ARH rats was lower than in the control and UAN rats. The amount of 18-0H-D0C secreted by the ARH rats did not differ from that of the AR rats. The ratios of B/18-0H-D0C, of B/DOC, and of B/progesterone, were significantly higher in the hypertensive ARH rats than in the normotensive adrenal enucleated rats, the progesterone/ pregnenolone ratio was lower. The B/18- OH-DOC ratio increased with the number of days allowed for adrenal regeneration in ARH rats and correlated positively with the blood pressure in the entire population of adrenal enucleated rats. The thymus weights correlated negatively with blood pressure and were significantly smaller in ARH than in AR rats. No catecholamines could be detected in the regenerated adrenal glands examined. Our findings indicate simultaneous aberrations in the functions of the adrenal gland, kidney and catecholamines, and suggest that a reduced glucocorticoid to mineralocorticoid ratio predisposes the animal to adrenal regeneration hypertension, but that glucocorticoid secretion becomes important for the overt manifestation of the syndrome. (Endocrinology93: 297, 1973)

This publication has 0 references indexed in Scilit: