Hibernation depth influences the edible dormouse pancreatic B cell during the spring arousal

Abstract

In order to determine the influence of hibernation depth upon the secretion and the effect of insulin, two groups of edible dormine were maintained in winter under different climatic and nutritional conditions, and their pancreatic B-cell function was tested during the spring arousal. The first group of animals was exposed to a moderate temperature and fed ad libitum. Their periods of hypothermia were short and irregular and the active periods sometimes lasted several days; their body weight increased during the winter months; in spring, the sensitivity of B cells to glucose was low, decreasing insulin secretion in vivo and in vitro, and the adipocytes were insulin resistant. The second group of fasting animals was exposed to a low and constant temperature (5°). Their phases of lethargy were long and regular (about 15 days), separated by active periods (6–8 hr); their body weight decreased during the winter months; in spring the B-cell secretion was increased and the sensitivity of the tissues to insulin ensured a high peripheral glucose utilization. These data show that the winter climatic and nutritional conditions which influence the depth of hibernation modify the edible dormouse B-cell activity during the spring arousal.