In vitro differentiation of preadipocytes from hypophysectomized pig fetuses

Hypophysectomy of the pig fetus alters the number of fat cells and fat cell clusters as well as lipogenic enzyme activities in tissues compared with littermate controls. The objective of the present study was to determine whether the altered endocrine environment in vivo affected subsequent development and differentiation of preadipocytes in vitro. Hypophysectomy was performed in utero at 70 d of gestation. At 105 d of gestation, stromal-vascular cells from dorsal subcutaneous adipose tissues were cultured in several differentiation media. Overall, stromal-vascular cultures from hypophysectomized fetuses contained fewer fat cell clusters and concomitantly lower glycerol-3-phosphate dehydrogenase specific enzyme activity than did cultures from littermate controls. Fluorescence-activated flow cytometry using a monoclonal anti-adipocyte/preadipocyte antibody designated AD-1 revealed that hypophysectomy also reduced the proportion of cells expressing the AD-1 cell surface antigen. These results demonstrated that effects of fetal hypophysectomy on cells from adipose tissues are maintained and measurable in culture. In addition, one of the consequences of fetal hypophysectomy may be diminution in the relative proportion of adipocyte precursors.