Effects of growth hormone on adipose tissue

Physiological effects of growth hormone (GH) extend beyond the stimulation of linear growth. These include important metabolic effects upon adipose ti ssue. GH affects both proliferation and differentiation of preadipocytes, a lthough this varies between clonal cell lines and preadipocyte cultures. Bo th preadipocytes and mature adipocytes possess specific GH receptors, CN ma y mediate its actions via these receptors, but some effects are indirectly mediated through the GH-mediated secretion of insulin-like growth factor-I (IGF-I) within adipose tissue, GH promotes lipolysis via inhibition of lipo protein lipase, which hydrolyzes triglycerides in the circulation to make t hem available for triglyceride accumulation in adipose tissue. GH also stim ulates hormone sensitive lipase (HSL), the rate-limiting step for release o f stored triglyceride in adipocytes (lipolysis), As GH becomes utilized for various "non-growth" concerns (see Figure 1), awareness of the metabolic e ffects on adipocytes is important to understand the clinical effects seen w ith GH therapy.