- 作者: Pei-Shan Liu; Pe-Yo Wang
- 作者服務機構: Department of Microbiology, Soochow University, Shihlin, Taipei, Taiwan, ROC
- 中文摘要: --
- 英文摘要: Dehydroepiandrosterone(DHEA) is a putative anti-stressagent and stress is associated with the secretion of cate-cholamine from the adrenal gland, but the effects ofDHEA on catecholamine secretion are not fully under-stood. Using bovine chromaffin cells, we found thatDHEA inhibited catecholamine secretion and cytosolicCa2+([Ca2+],)rise coupled with nicotinic acetylcholinereceptor(nAChR)without exerting an effect on 3H-nico-tine binding.In the case of high K+ stimulation,DHEAeffectively suppressed secretion without affecting [Ca2+]irise. Trifluoperazine (TFP),a calmodulin inhibitor, wascapable of counteracting the inhibition of DHEA on highK+-induced secretions. In permeabilized cells, DHEA sup-pressed the Cat2+-induced secretion. These results sug-gest that DHEA (a)acts as a channel blocker that sup-presses Ca2+ influx and subsequent secretions associat-ed with nAChR, or(b)affects the intracellular secretionmachinery to suppress high K+-induced secretions with-out affecting the high K+-induced【Ca2+】i rise.
- 中文關鍵字: --
- 英文關鍵字: --