Sympathetic neural discharge and vascular resistance during exercise in humans

摘要: The purpose of this study was to determine the relationship between changes in efferent muscle sympathetic nerve activity (MSNA) lower leg and calf vascular resistance (CVR) during isometric exercise humans. We made intraneural (microneurographic) determinations MSNA right (peroneal nerve) while simultaneously measuring blood flow left leg, arterial pressure, heart rate 10 subjects before (control), during, after (recovery) handgrip performed for 2.5 min at 15, 25, 35% maximal voluntary contraction (MVC). Heart pressure increased above control within initial 30 s all levels, magnitudes increases end were proportional intensity exercise. In general, neither nor CVR significantly levels 15% MVC. Similarly, variable 25 MVC; however, remainder period, progressive, parallel observed (P less than 0.05). correlation coefficients relating individual averaged 0.63 +/- 0.07 (SE) (range 0.30-0.91) 0.94 0.06 0.80-0.99) MVC respectively. During recovery, both returned rapidly toward levels. These findings demonstrate that discharge are tightly coupled arm Furthermore, exercise-induced adjustments two variables time dependent.