EFFECTS OF BODY AND HINDLIMB TEMPERATURE ON LASER-DOPPLER BLOOD-FLOW AND VASCULAR CONDUCTANCE IN RAT SCIATIC-NERVE AND SKELETAL-MUSCLE

The role of body and hindlimb temperature in the control of blood flow in nerve and muscle was assessed by laser Doppler flowmetry. Followin g surgical exposure of nerve, initial measurements were taken for 5 mi n at hindlimb temperatures of 30-31 degrees C. A second set of identic al measurements was then made either with or without warming to 37 deg rees C. Without warming, nerve laser Doppler flow (NLDF) increased by 14.51+/-3.2% (mean+/-SEM) but, with warming, decreased by 40.9+/-8.2%. In contrast, adduccamerontor magnus muscle laser Doppler flow (MLDF) decreased without warming (14.7+/-1.0%) and increased with warming (20 .4+/-12.8%). Because blood pressure was not significantly altered by c hanges in hindlimb temperature, the patterns of changes in vascular co nductance (laser Doppler flow/blood pressure) were not significantly d ifferent from that seen with NLDF and MLDF. Thus, warming to physiolog ical temperatures was associated with decreased NLDF and vascular cond uctance and increased MLDF and vascular conductance. These data may ha ve implications for the interpretation of nerve blood flow data obtain ed at different hindlimb temperatures. (C) 1997 Elsevier Science B.V.