Chapter 7 - Anterior Pituitary: Glycoprotein Hormones From Gonadotrope (FSH and LH) and Thyrotrope (TSH) Cells

Abstract

The glycoprotein hormone family has four well-known members in mammals. All four are dimers of a shared α subunit noncovalently bound to hormone-specific β subunits. Three of these proteins are synthesized by two cell types in the anterior pituitary gland. Gonadotropes produce the gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Thyrotropes synthesize thyrotropin or thyroid-stimulating hormone (TSH). The production and secretion of all three hormones depends on the activity of peptides from the brain. In turn, FSH, LH, and TSH have effects on distal target organs that produce hormones in response. FSH and LH stimulate sex steroid production by the gonads. TSH stimulates thyroid hormone synthesis in the thyroid gland. Sex steroids and thyroid hormones have actions throughout the body, regulating reproductive physiology and metabolism. They also feedback to the brain and pituitary to regulate their own synthesis. In this chapter, we review the evolution, structure, and mechanisms of action of the pituitary glycoprotein hormones. We also describe mechanisms regulating their synthesis. Finally, we highlight some gaps in knowledge that require future investigation.