Control of cell proliferation in the rat adrenal gland in vivo by the renin-angiotensin system. McEwan, Pauline. E., George B. Lindop, and Christopher J. Kenyon. University of Glasgow Department of Pathology and MRC Blood Pressure Unit,Western Infirmary, Glasgow, G11 6NT, UK
APStracts 3:0051E, 1996.
Adrenal cytogenesis was investigated in response to: a) s.c infusions of angiotensin (ANG) II (200ng.kg-1.min-1); b) high and low sodium intake; c) captopril treatment (10mg.kg-1.d-1). Cell proliferation was assessed as uptake of 5-bromo-2'-deoxyuridine (BrdUrd) into nuclei. BrdUrd, infused continuously throughout two weeks of treatment, was detected immunocytochemically. ANG II and sodium restriction caused hypertrophy of the zona glomerulosa with two -threefold increases in BrdUrd induces. After captopril, the glomerulosa appeared atrophied with pyknotic nuclei but the BrdUrd index was unchanged. Zonae intermedia and fasciculata were unaffected by any treatment. Zona reticularis epithelial cells proliferated in response to ANG II and sodium restriction but were unaffected by captopril. In the medulla, captopril increased BrdUrd uptake whereas ANG II, but not low sodium, caused a decrease. In conclusion: 1) proliferation of the glomerulosa and reticularis cells is specifiacally controlled by ANG II; 2) captopril may cause glomerulosa cells to die; 3) blood pressure may control proliferation of the medulla.

Received 23 October 1995; accepted in final form 15 February
1996.
APS Manuscript Number E508-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96