Absence of lipolytic activity from purified human growth hormone in cultured 3T3-L1 adipocytes.

Although standard preparations of growth hormone activated hormone-sensitive lipase in differentiated 3T3-L1 adipocytes, more highly purified preparations of human and bovine hormones were not lipolytic in this system. We found that the standard preparations were contaminated with a lipolytic substance which was removed during purification of the growth hormone. The purified growth hormone likewise did not stimulate lipolysis in adipose tissue from fasted rats. Dexamethasone had no potentiating activity in either assay.