Prolactin and somatomedin studies in the syndrome of growth hormone-independent growth.

Three children with hypothalamic mass lesions and continued linear growth in the absence of circulating growth hormone are presented. Serum growth hormone levels were either undetectable or very low both basally and following insulin-induced hypoglycaemia, whereas serum somatomedin levels were normal. Two subjects had elevated serum levels of prolactin, and in one of these prolactin suppression with bromoergocryptine failed to influence either somatomedin levels or urinary excretion of nitrogen, hydroxyproline and calcium. Although only one case was studied in detail these data suggest that maintenance of serum somatomedin and of normal growth in these children was not dependent upon prolactin secretion.