Local heat application to the leg reduces muscle sympathetic nerve activity in XXXX .

@entity1 @entity28681 @entity158
The study was designed to assess the effects of local heat (LH) application on postganglionic muscle sympathetic nerve activity (MSNA) measured by microneurography in healthy @entity1 . In the first protocol, MSNA of the left peroneal nerve, blood pressure (BP), heart rate (HR), and skin temperature of the shin ( @entity28681 ) were recorded in nine @entity1 . In the second protocol, leg blood flow (LBF) was measured in the same subjects by strain-gauge plethysmography. In both protocols, after 10 min of rest in the supine position, a heated hydrocollator pack was applied to the shin and anterior foot for 15 min and recovery was monitored over a period of 20 min. @entity28681 gradually increased from 31.7    0.1 to 41.9    0.5  C (mean    SEM) during LH. No subject complained of @entity158 , and BP and HR remained constant. The MSNA burst rate (16.1    2.1 beats/min) during the control period decreased significantly (P < 0.05) to 72.0    2.3% during LH. Total MSNA also decreased to 59.2    2.6% (P < 0.05) during LH, but both immediately returned to baseline at recovery. In contrast, LBF in the left leg significantly and immediately increased (P < 0.05) after LH application and remained significantly elevated until the end of the recovery period. These results suggest that: (1) LH application significantly attenuates MSNA without any changes in HR and BP. (2) Other factors in addition to MSNA seem to control regional blood flow in the lower extremity during LH.
