Effects of hindlimb temperature on sciatic nerve laser Doppler vascular conductance in control and streptozotocin-diabetic rats.

The effects of hindlimb temperature on sciatic nerve and skeletal muscle laser Doppler vascular conductance (LDVC) were assessed in anesthetized control and streptozotocin (STZ)-diabetic rats. With core temperature at 37 degrees C and exposed hindlimb temperature at 32 degrees C, nerve LDVC was significantly lower in rats after 8 weeks of STZ diabetes than in age-matched control rats. Subsequent warming of the exposed hindlimb of control rats from 32 degrees C to 37 degrees C significantly decreased nerve LDVC by 41% and increased muscle LDVC by 48%. Because nerve LDVC was unchanged by hindlimb warming in STZ-diabetic rats, there was no significant difference between control and diabetic nerve LDVC at 37 degrees C. In a second study, after 6 weeks of STZ diabetes, changes from control nerve LDVC were shown to depend on temperature rather than the duration of surgical exposure. These findings emphasize that information about hindlimb temperature is a prerequisite for interpreting the effects of experimental diabetes on hindlimb nerve blood flow.