Effects of insulin--like growth factor-I treatment on the endocrine pancreas of hypophysectomized rats: comparison with growth hormone replacement

In GH-deficient humans, GH and IGF-I treatment cause opposite effects on serum insulin concentrations and insulin sensitivity. This finding contrasts with the somatomedin hypothesis that IGF-I mediates GH action, as postulated for skeletal growth, and raises the question whether GH-induced IGF-I acts on the endocrine pancreas in the same way as administered IGF-I.