AJP - Regulatory, Integrative and Comparative Physiology, Vol 254, Issue 3 424-R430, Copyright © 1988 by American Physiological Society

ARTICLES

PGI2 attenuates baroreflex control of renal nerve activity by a vagal mechanism

I. H. Zucker, M. J. Panzenbeck, S. Barker, W. Tan and M. A. Hajdu
Department of Physiology and Biophysics, University of Nebraska College of Medicine, Omaha 68105.

The present study was undertaken to determine whether left circumflex coronary artery (ic) administration of prostacyclin (PGI2) caused an inhibition of the baroreflex control of renal sympathetic nerve activity (RSNA). RSNA was recorded in 12 dogs. Baroreflex sensitivity of RSNA was assessed by infusion of either sodium nitroprusside or phenylephrine and by determining the slope of the mean arterial pressure-RSNA relationship. During nitroprusside infusion, intracoronary PGI2 depressed the baroreflex sensitivity by nearly 90% compared with intracoronary tris(hydroxymethyl)aminomethane (Tris) (P less than 0.002). In addition, the peak increase in RSNA during nitroprusside infusion was significantly inhibited during intracoronary PGI2 (57.9 +/- 6.4 vs. 21.2 +/- 3.0 spikes/s, P less than 0.05). There was no significant difference in the inhibition of RSNA during phenylephrine infusion when intracoronary PGI2 was compared with Tris. Both bilateral vagotomy and pericoronary lidocaine blocked the inhibitory effects of PGI2 on the baroreflex increase in RSNA. It is concluded from these data that exogenously administered PGI2 stimulates or sensitizes afferent endings within the supply of the left circumflex coronary artery to inhibit the baroreflex control of RSNA during evoked hypotension. These afferents traverse vagal pathways via the pericoronary nerves. The role of endogenous prostaglandins in modulation of baroreflex function via a cardiac reflex remains to be elucidated.

This article has been cited by other articles:

				M. G. J. Gademan, R. J. van Bommel, C. Ypenburg, J. C. W. Haest, M. J. Schalij, E. E. van der Wall, J. J. Bax, and C. A. Swenne Biventricular pacing in chronic heart failure acutely facilitates the arterial baroreflex Am J Physiol Heart Circ Physiol, August 1, 2008; 295(2): H755 - H760. [Abstract] [Full Text] [PDF]

				K. D. Monahan and C. A. Ray Cyclooxygenase inhibition and baroreflex sensitivity in humans Am J Physiol Heart Circ Physiol, February 1, 2005; 288(2): H737 - H743. [Abstract] [Full Text] [PDF]

				D. Ely, M. Herman, L. Ely, L. Barrett, and A. Milsted Sodium intake is increased by social stress and the Y chromosome and reduced by clonidine Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2000; 278(2): R407 - R412. [Abstract] [Full Text] [PDF]

				M. Ek, M. Kurosawa, T. Lundeberg, and A. Ericsson Activation of Vagal Afferents after Intravenous Injection of Interleukin-1beta : Role of Endogenous Prostaglandins J. Neurosci., November 15, 1998; 18(22): 9471 - 9479. [Abstract] [Full Text] [PDF]

				W. Wang Cardiac sympathetic afferent stimulation by bradykinin in heart failure: role of NO and prostaglandins Am J Physiol Heart Circ Physiol, September 1, 1998; 275(3): H783 - H788. [Abstract] [Full Text] [PDF]