TURNOVER OF PLASMA GLUCOSE IN ANESTHETIZED WARM- AND COLD-ACCLIMATED RATS EXPOSED TO COLD

Abstract

The turnover of plasma glucose has been measured in anesthetized warm- and cold-acclimated white rats by a method involving a single injection of a tracer amount of uniformly labelled C14-glucose at 30 °C, and measurement of the rate of fall of the plasma glucose specific activity in animals maintained at 30 °C or moved to an environment at 6 °C. Analysis of the data indicated a significant increase in the rate of disappearance of the labelled glucose when the warm-acclimated rats were transferred from 30° to 6 °C but no significant change when the cold-acclimated rats were similarly treated. The concentration of plasma glucose remained essentially constant throughout the observation period. These results may be taken to indicate that the cold-induced increase in metabolism of anesthetized white rats is associated with an increase in plasma glucose turnover in warm-acclimated animals only.