Effects of cold acclimation and deacclimation on glycogen metabolism in the liver of obese and lean Zucker rats

The effects of long-term cold exposure (10 °C for 11weeks) and of deacclimation from cold (25 °C for 2 weeks, after 10 °C for 9 weeks) were investigated in obese and lean Zucker rats. Morphological change was observed in the liver during cold acclimation and deacclimation. Hepatic glycogen content decreased during cold adaptation, more markedly in obese rats. However, plasma glucose levels remained unchanged. After deacclimation, the glycogen content increased when compared to the original level, conspicuously in lean rats. Leptin receptor protein was decreased by cold acclimation in lean, but not obese, rats. Cold acclimation and deacclimation had no effect on expression of GLUT2 or PGC1 protein in either strain.