Utilization of acetate-1-C¹⁴ by hepatic tissue from cold-exposed and hibernating hamsters

¹ Biology Department, Queen's University, Kingston, Ontario, Canada

When the hamster is exposed to cold (6 ± 1 C), there is a profound block in hepatic lipogenesis from C¹⁴-acetate within 48 hr. By 8 weeks of cold exposure this block has been repaired to 74% of the control value. During hibernation, which generally occurs after the 8th week, a block in lipogenesis is again present. By 6 hr of arousal, the degree of lipogenesis has been either slightly repaired or has returned almost to the 8-week level. Accompanying this block in lipogenesis is an increase in the production of C¹⁴O₂ from C¹⁴-acetate in animals exposed to cold. In vitro addition of .02 m glucose did not stimulate lipogenesis in hepatic tissue of cold-exposed hamsters, except for a few of those animals aroused from hibernation for 6 hr. Addition of .02 m succinate in vitro did not increase lipogenesis or C¹⁴O₂ production from C¹⁴-acetate. Fructose repaired the hepatic lipogenesis in all groups of cold-exposed hamsters. It was concluded that the cold-exposed and hibernating hamster has biochemical lesions involving the glucokinase reaction and some other step in the glycolytic pathways of the liver.