A survey of growth hormone secretion and action

The many stimuli of HGH secretion have been considered, and the major aspects of HGH's actions briefly reviewed. We have advanced our reasons for believing that some actions attributed to HGH are basically pharmacologic. This applies, in particular, to the so-called “insulinlike” effects. A detailed examination of specific effects of HGH has been made in the light of this assumption. We have indicated that SF may mediate many of GH's effects, in particular, the effects of HGH on protein, collagen, and polysaccharide synthesis in cartilage, and possibly, HGH's anabolic effects in skeletal muscle. Clearly, one of the major problems confronting investigators is to delineate clearly which effects of HGH are direct, and which are mediated by a second factor. An allied and no less important problem is to determine which of these effects are physiologic and where in the human these effects occur. A basic understanding of the complex secretory mechanism for HGH seems much more advanced than progress in solving the latter problems.