Interrelations of vasoconstrictor sympathetic outflow to skin and core temperature during unilateral sole heating in humans

Abstract The purpose of the present study was to clarify how skin sympathetic nerve activity (SSNA) influences the core temperature during local heating of the unilateral sole of the foot for 60 min. We recorded SSNA microneurographically from the tibial or peroneal nerve simultaneously with skin blood flow, sweat rate at heated and non-heated sites, with tympanic temperature ( T ty ) as the core temperature. Sole heating began to suppress vasoconstrictive SSNA (vasoconstrictor) after 3.4±1.1 min, decrease T ty after 7.4±2.0 min, activate vasoconstrictor after 33.4±2.2 min, and increase T ty after 45.5±2.7 min. Regarding the interaction between vasoconstrictor and T ty during sole heating, we found the following: (1) the capability to suppress vasoconstrictors (decrease rate) showed positive correlations with the time delay from vasoconstrictor suppression to the T ty decrease ( r =0.752, p T ty decrease rate ( r =0.795, p T ty decrease rate was inversely related to the capability to activate vasoconstrictors (increase rate) ( r =−0.836, p T ty increase ( r =−0.856, p T ty increase rate ( r =0.819, p