Endocrine Abstracts

There are several regulatory systems the body that keep body functions, like body temperature and blood glucose, constant. In this study we have added and removed weight loads from experimental animals and measured the effects on biological body weight. The results of these experiments indicate that there is a novel regulatory mechanism to keep the body weight constant, mostly by adjusting the body fat mass. The mechanism was dependent on intact bone cells. We hypothesize that there is a sensor for body weight in the long bones of the lower extremities acting as ‘body scales’. This is part of regulatory system, a gravitostat, that keeps body weight and body fat mass constant. Later findings demonstrate that the gravitostat regulates fat mass in obese mice while leptin regulates fat mass only in lean mice with low endogenous serum leptin levels. We propose that activation of the gravitostat primarily protects against obesity while low levels of leptin protects against undernutrition.