Prolactin and Growth Hormone Synthesis: Effects of Perphenazine, -Methyltyrosine and Estrogen in Different Thyroid States

Abstract

The effects of thyroid hormones on prolactin (PRL) and growth hormone (GH) synthesis by the rat anterior pituitary gland were assessed in vitro. A marked reduction (84–87%) in the rate of H³-leucine incorporation into GH was evident 2–4 weeks after thyroidectomy, while incorporation into PRL was 52–71% less than that measured in glands from intact rats. A single injection of T₄ (200 μg/kg) administered to thyroidectomized (THX) rats 48 hr before sacrifice significantly increased incorporation into both pituitary hormones, although the stimulation of GH synthesis was much more dramatic.