The interaction between vitamin A and thiazolidinedione on bovine adipocyte differentiation in primary culture.

We studied the effects of a thiazolidinedione (T-174) and retinoids on adipocyte differentiation in beef cattle. Stromal-vascular (SV) cells containing preadipocytes were prepared from perirenal adipose tissue of 21-mo-old Japanese Black steers. After confluence, these cells were cultured in 25 microM T-174, which is a specific ligand for an adipogenesis stimulating nuclear receptor (i.e., gamma subtype of peroxisome proliferator-activated receptor [PPARgamma]), with 1 microM all-trans retinoic acid (RA) or .4 to 40 microg/100 mL of retinol for 10 to 14 d. The number of cells accumulating lipid droplets was counted as morphologically differentiated adipocytes, and the activity of glycerol-3-phosphate dehydrogenase (GPDH), a biochemical index for the differentiation, was determined. The number of lipid-laden cells and GPDH activity were increased by the addition of T-174. All-trans retinoic acid completely blocked the stimulative action of T-174. The addition of retinol also decreased the number of lipid-laden cells and GPDH activity in a dose-dependent manner. These results showed that the thiazolidinedione stimulated adipocyte differentiation and the retinoids blocked the adipogenesis induced by the thiazolidinedione in primary culture of bovine SV cells. Peroxisome proliferator-activated receptor gamma may play an important role in adipocyte differentiation, and retinoids may interfere with the action of PPARgamma in cattle.