Journal of Applied Physiology, Vol 67, Issue 5 1791-1800, Copyright © 1989 by American Physiological Society

ARTICLES

Differential control of forearm and calf vascular resistance during one-leg exercise

J. A. Taylor, M. J. Joyner, P. B. Chase and D. R. Seals
Department of Exercise and Sport Sciences, University of Arizona, Tucson 85721.

The purpose of this study was to determine whether blood flow (BF) and vascular resistance (VR) are controlled differently in the nonactive arm and leg during submaximal rhythmic exercise. In eight healthy men we simultaneously measured BF to the forearm and calf (venous occlusion plethysmography) and arterial blood pressure (sphygmomanometry) and calculated whole limb VR before (control) and during 3 min of cycling with the contralateral leg at 38, 56, and 75% of peak one-leg O2 uptake (VO2). During the initial phase of exercise (0-1.5 min) at all work loads, BF increased and VR decreased in the forearm (P less than 0.05), whereas calf BF and VR remained at control levels. Thereafter, BF decreased and VR increased in parallel and progressive fashion in both limbs. At end exercise, forearm BF and VR were not different from control values (P greater than 0.05); however, in the calf, BF tended to be lower (P less than 0.05 at 75% peak VO2 only) and VR was higher (23 +/- 9, 44 +/- 14, and 88 +/- 23% above control at 38, 56, and 75% of peak VO2, respectively, all P less than 0.05). In a second series of studies, forearm and calf skin blood flow (laser-Doppler velocimetry) and arterial pressure were measured during the same levels of exercise in six of the subjects. Compared with control, skin BF was unchanged and VR was increased (P less than 0.05) in the forearm by end exercise at all work loads, whereas calf skin BF increased (P less than 0.05) and VR decreased (P less than 0.05). The present findings indicate that skeletal muscle and skin VR are controlled differently in the nonactive forearm and calf during the initial phase of rhythmic exercise with the contralateral leg. Skeletal muscle vasodilation occurs in the forearm but not in the calf; forearm skin vasoconstricts, whereas calf skin vasodilates. Finally, during exercise a time-dependent vasoconstriction occurs in the skeletal muscle of both limbs.

This article has been cited by other articles:

				D. Green, C. Cheetham, L. Mavaddat, K. Watts, M. Best, R. Taylor, and G. O'Driscoll Effect of lower limb exercise on forearm vascular function: contribution of nitric oxide Am J Physiol Heart Circ Physiol, September 1, 2002; 283(3): H899 - H907. [Abstract] [Full Text] [PDF]

				J. A. Pawelczyk, J. H. Zuckerman, C. G. Blomqvist, and B. D. Levine Regulation of muscle sympathetic nerve activity after bed rest deconditioning Am J Physiol Heart Circ Physiol, May 1, 2001; 280(5): H2230 - H2239. [Abstract] [Full Text] [PDF]

				J. K. Shoemaker, M. D. Herr, and L. I. Sinoway Dissociation of muscle sympathetic nerve activity and leg vascular resistance in humans Am J Physiol Heart Circ Physiol, September 1, 2000; 279(3): H1215 - H1219. [Abstract] [Full Text] [PDF]

				J. A. Pawelczyk and B. D. Levine Heterogeneous responses of human limbs to infused adrenergic agonists: a gravitational effect? J Appl Physiol, May 1, 2002; 92(5): 2105 - 2113. [Abstract] [Full Text] [PDF]

				J. M. Legramante, A. Galante, M. Massaro, A. Attanasio, G. Raimondi, F. Pigozzi, and F. Iellamo Hemodynamic and autonomic correlates of postexercise hypotension in patients with mild hypertension Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2002; 282(4): R1037 - R1043. [Abstract] [Full Text] [PDF]