Effects of lipid-related factors on adipocyte differentiation of bovine stromal-vascular cells in primary culture

The effects of several factors related to lipids on bovine adipocyte differ entiation were investigated in primary culture. Adipocyte differentiation w as assessed by development of glycerol-3-phosphate dehydrogenase (GPDH) act ivity and morphological observation. Addition of triglyceride mixture (Intr alipid), caprylic acid and very low-, low- and high-density lipoproteins (V LDL, LDL and HDL) stimulated bovine preadipocyte differentiation in serum-f ree condition. Especially, VLDL strongly increased both cell protein conten ts and GPDH activity, suggesting that it stimulated both proliferation and differentiation of bovine preadipocytes. Under Intralipid-induced condition , differentiation of preadipocytes from subcutaneous adipose tissues was mo re evident than those from omental adipose tissues. However, such depot dif ference was not observed in medium supplemented with indomethacin, which is a peroxisome proliferator-activated receptor (PPAR) gamma agonist. This su ggests that the differentiation capacity of bovine preadipocytes was differ ent between depots and such difference is dependent on the ability to utili ze lipids as endogenous PPAR gamma ligands. Therefore, lipid metabolites ha ve the stimulatory effects on bovine adipocyte differentiation in vitro, an d lipoproteins, especially VLDL, may play an important role in development of bovine adipose tissues in vivo.