Local cerebral glucose utilization decreases after heatstroke onset in rats

The quantitative autoradiographic 2-[(14)C]-deoxy-D-glucose methods were used to assess the local cerebral glucose utilization (LCGU) in 46 brain structures in rats suffering from heatstroke. Heatstroke was induced by exposing the animals to an ambient temperature of 42 degrees C. The time at which the local cerebral blood flow (CBF) and mean arterial pressure (MAP) decreased from their peak levels was taken as the onset of heatstroke. Control rats were exposed to a temperature of 24 degrees C. The values of local CBF, MAP and means of total LCGU after heatstroke onset were all significantly lower than those in control rats. However, the values of colonic temperature were greater. Thus, it appears that the decreased cerebral metabolism and perfusion can be due to secondary effect of hypertension after heatstroke onset.