- 作者: Ling-Ling Chang; Wan-Song Alfred Wun; Paulus S. Wang
- 作者服務機構: Department of Chemical Engineering, Chinese CultureUniversity, Shih-Lin, Taipei 111, Taiwan, Republic of China; Obstetrical and Gynecological Associates, P.A.,Houston, TX, USA; Department of Physiology, School of Medicine, NationalYang-Ming University, Taipei, Taiwan, Republic of China
- 中文摘要: --
- 英文摘要: The present study was to investigate the effectsand action mechanisms of dehydroepiandrosterone (DHEA)on steroidogenesis in rat adrenal zona glomerulosa cells(ZG). ZG cells were incubated withDHEA in the presence orabsence of angiotensin II (AngII), a high concentration ofpotassium, 8-Br-cAMP, forskolin, 25-OH-cholesterol,pregnenolone, progesterone, deoxycorticosterone, corticosterone,A23187, or cyclopiazonic acid (CPA) at 37C for1 h. The concentration of aldosterone or pregnenolone inthe culture medium was then measured by radioimmunoassay(RIA). The cells were used to determine the cellularcAMP content. The data demonstrated that: (1) DHEAinhibited AngII-, high concentration of KCl-, forskolin-,8-Br-cAMP-, 25-OH-cholesterol-, pregnenolone-, progesterone-,deoxycorticosterone-, corticosterone-, A23187-, orCPA-stimulated aldosterone release; (2) DHEA increased25-OH-cholesterol-stimulated pregnenolone release but notwhen 25-OH-cholesterol was combined with trilostane; (3)DHEA noncompetitively inhibited aldosterone synthase butshowed uncompetitive inhibition of P450scc. These resultssuggest that DHEA acts directly on rat ZG cells to diminishaldosterone secretion by inhibition of a post-cAMP pathwayor by acting on intracellular Ca2+ mobilization. In addition itaffects the function of post-P450scc steroidogenic enzymes.
- 中文關鍵字: --
- 英文關鍵字: cAMP; DHEA; Ca2+; Steroidogenesis; Zona glomerulosa cells