VEGF mRNA in adipocytes increase with rebound weight-gain after diet-restriction.

The mechanism of rebound body weight-gain after a restricted-diet state is unclear. We investigated the expression of angiogenic factors in human adipocytes with a changing nutritional state in culture medium, and attempted to ascertain the mechanisms involved in rebound weight-gain. Adipocytes were divided into three groups; the first group (control group) was cultured in medium with 10% fetal calf serum (FCS), the second (DR3% group) was cultured in medium with 3% FCS, and the third (DR6% group) was cultured in medium with 6% FCS. After being cultured for 48 h, each was next cultured with 12% FCS for a further 48 h. When made to change from a low nutrition state to a higher one, adipocytes changed from hypotrophic to hypertrophic. Simultaneously, vascular endothelial growth factor (VEGF) in the culture medium increased significantly. When investigated immunohistochemically, the expression of VEGF was similarly shown in the cytoplasm of adipocytes. The same tendency with the same quantity of mRNA was shown by RT-PCR. These results show that VEGF produced and secreted from adipocytes increases, when the cultivation state of adipocytes is changed from a low nutritional state to a higher one. VEGF produced and secreted from adipocytes may be related to rebound weight-gain.