- 作者: Ching-Jiunn Tseng Julie Y.H. Chan Wan-Chen Lo Chung-Ren Jan
- 作者服務機構: Depatrment of Medical Education and Research, Kaohiung Veterans General Hospital, taiwan, ROC
- 中文摘要: --
- 英文摘要: Adenosine was shown to inhibit norepinephrine (NE)release from sympathetic nerve endings. The purpose ofthis study was to examine whether endogenous adeno-sine restrains NE and epinephrine release from the adre-nal medulla. The effects of an adenosine receptor antag-onist, 1,3-dipropyl-8-(p-sulfophenyl) xanthine (DPSPX),on epinephrine and NE release induced by intravenousadministration of insulin in conscious rats were exam-ined. Plasma catecholamines were measured by HPLCwith an electrochemical detector. DPSPX significantlyincreased plasma catecholamine in both control rats andrats treated with insulin. The effect of DPSPX on plasmacatecholamine was significantly greater in rats treatedwith insulin. Additional experiments were performed inadrenalectomized rats to investigate the contribution ofthe adrenal medulla to the effect of DPSPX on plasmacatecholamine. The effect of DPSPX and insulin on epi-nephrine in adrenalectornized rats was significantly re-duced compared with that of the controls. Finally, wetested whether endogenous adenosine restrains cate-cholamine secretion partially through inhibiting the re-nin-angiotensin system. The effect of DPSPX on plasmacatecholamine in rats pretreated with captopril (an an-giotensin-converting enzyme inhibitor) was reduced.These results demonstrate that under basal physiologi-cal conditions, endogenous adenosine tonically inhibitscatecholamine secretion from the adrenal medulla, andthis effect is augmented when the sympathetic system isstimulated. The effect of endogenous adenosine on cate-cholamine secretion from the adrenal medulla isachieved partially through the inhibitory effect of adeno-sine on the renin-angiotensin system.
- 中文關鍵字: --
- 英文關鍵字: Adenosine. Adrenal Medulla. Captopril Catecholamine. Insulin. Renin-Angiotensin system