Changes in food intake and growth rate in mice under hypergravity.

Mice exposed to hypergravity, especially soon after start of exposure, diminished the body weight and the food intake. The amount of food intake was kept less than that of the ground control during hypergravity breeding for 2 weeks. Furthermore, the weight of testis relative to the body weight increased compared to that of 1 G control although the relative weights of liver and kidney were not changed. The purpose of this study was whether the low growth rate of the body weight and the increase of the relative testis weight were induced by the decrease of the food intake under hypergravity. We divided 3 weeks old male mice to 3 groups; the 1 G (ground control), the food restricted (FR) under 1 G, and the 3 G group. The 3 G group bred for 2 weeks under the centrifuge at 3 G. The FR group was given the same amount of food as the group ate. The changes in the body weight and the relative weights of testis, spleen and seminal vesicle of the FR group were similar to those of the 3 G group. The hunger test revealed that only the FR group was hunger. Our results suggested that the decrease of the food intake both in response to hypergravity and the food restriction induced the decrease of the body weight but the increase of the relative testis weight.