Regulation of the body weight of the european hamster during the annual cycle

Summary The effects of body weight losses of European Hamsters after food deprivation were investigated at various periods of the year. In November and December normally occurs a body weight decrease which can be accelerated by food deprivation. When the animals have again access to food, they either reduce their weight loss or regain weight according to the importance of the previous weight loss. Weight gain after food deprivation proceeds at rates which vary with the season; the rate is faster in spring and summer than in autumn and winter. It is concluded that body weight is regulated and that two characteristics of the regulating mechanism (somatostat) undergo circannual variations: the level of the set point and the rate of weight loss compensation.With the technical assistance of Miss A. Koch (C.N.R.S.).