Thermoregulatory responses of diabetic rats

Abstract 1. 1. Thermal responses and skin microcirculation were measured in streptozotocin-induced diabetic (SD) rats during acute and chronic exposure to ambient ( T a ) temperatures ranging from about 5 to 35°C. 2. 2. At 28°C, SD rats had higher rate of oxygen consumptions ( V O 2 ), tail skin blood flow (SKBF), but lower rectal temperatures ( T re ) than saline-injected controls. 3. 3. Chronic exposure of the SD rats to 35 and 5°C caused a sharp rise and decline in T re , respec- tively. 4. 4. At 35°C, hyperthermia in the SD rats was associated with greater increase in V O 2 than controls, but changes in SKBF were similar in both groups. 5. 5. At 5°C, V O 2 changed similarly in both the SD and control rats, but vasoconstriction was greater in the controls. 6. 6. The data suggest that hypothermia in SD rats may be associated with impairment of vasconstriction and hyperthermia may be related to an increase V O 2 not accompanied by greater vasodilation.