AJP - Heart and Circulatory Physiology, Vol 258, Issue 3 842-H847, Copyright © 1990 by American Physiological Society

ARTICLES

Regional vascular resistance during exercise: role of cardiac afferents and exercise training

S. E. DiCarlo and V. S. Bishop
Department of Pharmacology, University of Texas Health Science Center, San Antonio 78284-7764.

This study was designed to determine whether cardiac vagal afferents exert an inhibitory influence on increases in regional vascular resistance during exercise and to determine whether endurance exercise training enhances the inhibitory influence of cardiac vagal afferents. We measured changes in regional vascular resistance in 12 rabbits at rest and during running at 12.6 m/min, 20% grade, before and after reversible denervation of cardiac afferents (intrapericardial procainamide HCl, 2%). In addition, these procedures were repeated in five of these rabbits following an 8-wk endurance exercise training program. Because intrapericardial injections of procainamide anesthetize both the efferent as well as the afferent innervation to the heart, it was necessary to determine the effects of blocking the efferent innervation on the regulation of regional vascular resistance during exercise. Rabbits were instrumented with Doppler ultrasonic flow probes around the renal (R), mesenteric (M), ascending, and terminal aortic (TA) arteries. Catheters were positioned in the central ear artery and vein and pericardial sac. Mean arterial pressure, heart rate, cardiac output, R, M, TA, and systemic (S) resistances were determined. Exercise changed R (+37 +/- 4%), M (+88 +/- 9%), TA (-62 +/- 6%), and S (-34 +/- 3) resistances. Subsequent cardiac efferent blockade alone had no significant effect on regional vascular resistance during exercise. Combined efferent and afferent blockade resulted in significant increases in R (+62 +/- 6%) and M resistance (+134 +/- 13%) but did not alter TA (-51 +/- 4%) or S (-27 +/- 2%) resistance during exercise. Exercise training significantly enhanced the inhibitory influence of cardiac afferents on R and M regional vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				R d. Moraes, R H Valente, I R Leon, M R O Trugilho, A C L Nobrega, J Perales, and E Tibirica Chronic dynamic exercise increases apolipoprotein A-I expression in rabbit renal cortex as determined by proteomic technology Br. J. Sports Med., May 1, 2008; 42(5): 386 - 388. [Abstract] [Full Text] [PDF]

				H. Zheng, Y.-F. Li, K. G. Cornish, I. H. Zucker, and K. P. Patel Exercise training improves endogenous nitric oxide mechanisms within the paraventricular nucleus in rats with heart failure Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2332 - H2341. [Abstract] [Full Text] [PDF]

				R. D. Moraes, G. Gioseffi, A. C. L. Nobrega, and E. Tibirica Effects of exercise training on the vascular reactivity of the whole kidney circulation in rabbits J Appl Physiol, August 1, 2004; 97(2): 683 - 688. [Abstract] [Full Text] [PDF]

				R. U. Pliquett, K. G. Cornish, K. P. Patel, H. D. Schultz, J. D. Peuler, and I. H. Zucker Amelioration of depressed cardiopulmonary reflex control of sympathetic nerve activity by short-term exercise training in male rabbits with heart failure J Appl Physiol, November 1, 2003; 95(5): 1883 - 1888. [Abstract] [Full Text] [PDF]

				K. P. O'Hagan and J. A. Alberts Uterine artery blood flow and renal sympathetic nerve activity during exercise in rabbit pregnancy Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2003; 285(5): R1135 - R1144. [Abstract] [Full Text] [PDF]

				J.-L. Liu, J. Kulakofsky, and I. H. Zucker Exercise training enhances baroreflex control of heart rate by a vagal mechanism in rabbits with heart failure J Appl Physiol, June 1, 2002; 92(6): 2403 - 2408. [Abstract] [Full Text] [PDF]

				B. Martinez-Nieves, H. L. Collins, and S. E. DiCarlo Arterial baroreflex regulation of regional vascular conductance at rest and during exercise Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2000; 278(6): R1634 - R1642. [Abstract] [Full Text] [PDF]

				P. J. Mueller, K. P. O'Hagan, K. A. Skogg, J. B. Buckwalter, and P. S. Clifford Renal hemodynamic responses to dynamic exercise in rabbits J Appl Physiol, November 1, 1998; 85(5): 1605 - 1614. [Abstract] [Full Text] [PDF]

				L. G. KOCH, S. L. BRITTON, J. C. BARBATO, D. W. RODENBAUGH, and S. E. DICARLO Phenotypic differences in cardiovascular regulation in inbred rat models of aerobic capacity Physiol Genomics, August 31, 1999; 1(2): 63 - 69. [Abstract] [Full Text] [PDF]