Lack of growth hormone-dependent somatomedins or growth retardation in hypophysectomized fetal lambs.

Fetal lambs were hypophysectomized and, after 8 days of recovery, given infusions of GH, prolactin, thyroxine and insulin with glucose. Hypophysectomy caused no consistent reduction in fetal plasma somatomedin-like activity. Fetal infusions of GH or prolactin caused no consistent change in plasma somatomedin-like activity. It was concluded that fetal somatomedin-like activity is not GH dependent. After hypophysectomy fetal lambs showed no reduction in body weight or length at term.