The lipolytic effects of thyrotropin and isoprenaline are not affected by growth hormone in infant adipocytes.

The lipolytic effects of growth hormone (GH) in children are not fully clarified. In this study, no lipolytic effect of GH on isolated adipocytes obtained at surgery on healthy infants aged 2-5 months and children 3-6 years was observed. Furthermore, GH did not enhance isoprenaline-induced lipolysis, as in adults. The TSH-induced lipolysis which is prominent in neonatal adipocytes was not affected by incubation of adipocytes with GH. Assuming that GH alters adipocyte metabolism primarily by increasing the sensitivity, but not the maximum response, of the beta 2-adrenergic receptor population, it follows that GH, in this sense, should be a less important co-actor in children where beta 2-adrenergic receptors are more abundant.