The Interrelationships of Thyroid and Growth Hormones: Effect of Growth Hormone Releasing Hormone in Hypo- And Hyperthyroid Male Rats

Acta Endocrinol Suppl (Copenh). 1986;279:367-75. doi: 10.1530/acta.0.112s367.

Abstract

Growth hormone (GH) and the thyroid hormones interact in the hypothalamus, pituitary and peripheral tissues. Thyroid hormone exerts a permissive effect upon the anabolic and metabolic effects of GH, and increases pituitary synthesis of this protein hormone. GH depresses the secretion of thyrotropin and the thyroid hormones and increases the peripheral conversion of thyroxine to triiodothyronine. In the adult male rat experimental hypothyroidism produced by ingestion of propylthiouracil depresses the GH secretory response to GH-releasing hormone in vivo and in vitro, reflecting the lowered pituitary stores of GH in the hypothyroid state. Short term administration of large amounts of thyroxine with induction of the hyperthyroid state does not affect the in vivo GH secretory response to GH-releasing hormone in this animal.

MeSH terms

  • Animals
  • Growth Hormone / metabolism*
  • Growth Hormone-Releasing Hormone / pharmacology*
  • Hyperthyroidism / chemically induced
  • Hyperthyroidism / physiopathology*
  • Hypothyroidism / chemically induced
  • Hypothyroidism / physiopathology*
  • Male
  • Pituitary Gland / drug effects
  • Pituitary Gland / physiopathology
  • Propylthiouracil
  • Rats
  • Thyroid Hormones / physiology*
  • Thyroxine / blood

Substances

  • Thyroid Hormones
  • Propylthiouracil
  • Growth Hormone
  • Growth Hormone-Releasing Hormone
  • Thyroxine