The effect of human placental lactogen upon the metabolism of rat and human adipose tissue.

The metabolic effects of human placental lactogen (HPL) on rat and human white fat were tested in vitro. When tested against rat tissue, HPL resembled insulin in stimulating uptake of glucose and incorporation of [14C] glucose into CO2, triglyceride and glycogen, but differed from insulin in stimulating glycerol release and in failing to stimulate the incorporation of [14C] The stimulation of [14C] glucose incorporation and the inhibition of glycerol release by insulin were antagonized by HPL. The effects of HPL on human white fat resembled those on rat white fat,except that glycerol release was not stimulated in human tissue. The possible role of HPL in causing the diabetogenic stress of pregnancy is discussed in the light of these findings.