Human adipose tissue in culture. VII. The long-term effect on growth hormone

Biopsies of human adipose tissue were cultured for one week in vitro with or without different concentrations of human growth hormone (GH). After preincubation they were incubated in vitro for 2 hours analogous to the technique generally used for short-term experiments. The release of glycerol and incorporation of glucose into triglycerides were measured under basal conditions as well as in the presence of insulin or noradrenaline. An impairment in the basal glucose incorporation rate was found after the culture period with GH, but there was no concomitant effect on lipolysis. The effect of insulin on glucose incorporation was stimulating to the same extent as in the controls but the metabolis rate was even in the presence of insulin still below that of the controls. The effects of noradrenaline and of insulin on lipolysis were similar to those in the control group. It is concluded from the present study that a direct "diabetogenic" effect of GH on human adipose tissue can be detected. This effect developed successively over the seven days that the incubations were performed. It was due to a diminished basal rate of glucose incorporation and not to a direct resistance to the action of insulin and it was not related to increased lipolysis.