Androgen regulation of rat renal angiotensinogen messenger RNA expression

Renal angiotensinogen (ang-n) mRNA concentration in the male WKY rat increases significantly during puberty. Further-more, renal angiotensinogen mRNA level in the adult female WKY rat is considerably lower than in the male. The present study investigates the role of androgen in differential renal ang-n mRNA expression. Northern and slot blot analyses with a-32P labeled ang-n cDNA (pRang 3) demonstrated that cas-tration lowered ang-n mRNA levels in the male kidney by 2 60 % compared with control, suggesting that androgen may be involved with renal ang-n gene regulation. Moreover, male WKY rats castrated as weanlings and normal adult female WKY rats each implanted with testosterone displayed signifi-cant (P < 0.05) increases in renal ang-n mRNA levels. Our observations, taken together with previous reports that andro-gen influences proximal tubule morphology and the tubular expression of transport proteins (e.g., Na+/H+ antiporter), may have important physiological implications for under-standing the relationship between androgen and angiotensin in the regulation of tubular function