Autonomic mediation of the pressor responses to isometric exercise in humans

• DOI: 10.1152/jappl.1988.64.5.2190
• Publication Date: 2017-12-21T16:40:12Z
• Authors: D. R. Seals; P. B. Chase; J. A. Taylor
• Keywords: Microneurography

The purpose of this study was to determine the respective contributions tachycardia and increases in sympathetic nerve activity (SNA) mediating pressor responses fatiguing vs. nonfatiguing levels isometric handgrip exercise (IHE) humans. We performed direct (microneurographic) measurements muscle SNA from right peroneal leg recorded arterial pressure (AP) heart rate (HR) eight healthy subjects before (control), during, after 2.5 min IHE at 15, 25, or 35% maximal voluntary contraction (MVC). At 15% MVC, AP increased during initial 1.5 (7 mmHg, P less than 0.05) remained level; 25 throughout (22 34 mmHg control, respectively, 0.05). HR all three (5, 12, 19 beats/min, but did not increase further over last minute. above control; 1st progressively thereafter (109 205% magnitudes average minute were directly related (r = 0.99, 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)