|
|
||||||||
AJP - Heart and Circulatory Physiology, Vol 250, Issue 1 144-H148, Copyright © 1986 by American Physiological Society
ARTICLES |
M. Nakamaru, E. K. Jackson and T. Inagami
Essential components of the renin-angiotensin system such as renin enzymes, angiotensinogen, converting enzyme, and angiotensin receptors have been found in vascular tissues. Locally generated angiotensin (ANG) II may regulate vascular tone by contracting vascular smooth muscle or potentiating sympathetic activity. Recently it was suggested that beta-adrenoceptor-induced enhancement of noradrenergic neurotransmission is mediated by the vascular renin-angiotensin system. The present study was designated to obtain direct evidence for the release of ANG II from the vasculature by beta-adrenoceptor activation. Isolated rat mesenteric arteries were perfused in vitro with Krebs-Ringer solution, and released ANG II was concentrated in a Sep-Pak C-18 cartridge connected to the perfusion system. High-pressure liquid chromatography combined with radioimmunoassay clearly demonstrated the presence of ANG I, II, and a small amount of ANG III in the perfusate. Isoproterenol (10(-9) - 10(-6) M) induced the enhancement of pressor responses to nerve stimulation. This effect was markedly suppressed by propranolol (5 X 10(-7) M), captopril (2 X 10(-6) M), or [Sar1-Ile8]ANG II (10(-6) M). Isoproterenol (10(-9) - 10(-6) M) caused increase in the release of ANG II from mesenteric arteries. The increase in ANG II release during isoproterenol (10(-6) M) infusion was blocked by propranolol (10(-6) M). Captopril (2 X 10(-6) M) also inhibited the increase in ANG II induced by isoproterenol. These results indicate that locally generated ANG II is released from isolated perfused rat mesenteric arteries and its release is mediated by beta-adrenoceptors.
This article has been cited by other articles:
![]() |
Y. Zhou, P. Bouyer, and W. F. Boron Role of the AT1A receptor in the CO2-induced stimulation of HCO3- reabsorption by renal proximal tubules Am J Physiol Renal Physiol, July 1, 2007; 293(1): F110 - F120. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |