Growth hormone (GH), also known as somatotropin or human growth hormone (hGH), is a peptide hormone produced by the anterior pituitary gland that is crucial for growth, cell reproduction, and regeneration. This 191-amino acid polypeptide stimulates the production of insulin-like growth factor 1 (IGF-1) and influences glucose and fatty acid concentrations, making it a key area of study in endocrinology, metabolism, and developmental biology.
Key Functions and Regulatory Mechanisms:
Growth and Development: GH stimulates bone and tissue growth, especially during childhood and puberty, by stimulating epiphyseal growth plates and promoting bone elongation.
Metabolic Regulation: GH regulates metabolism by assisting in transporting molecules, conserving sugars, building proteins, and breaking down fats. It opposes insulin's action, increasing fat breakdown to provide energy.
IGF-1 Production: GH stimulates the liver and other tissues to produce insulin-like growth factor 1 (IGF-1), which mediates many of GH's growth-promoting effects.
Pituitary Control: GH secretion is stimulated by growth hormone-releasing hormone (GHRH) and inhibited by somatostatin, both released from the hypothalamus. GH secretion is pulsatile, with surges occurring after the onset of deep sleep.
Research Applications and Clinical Significance:
Growth Disorders: Recombinant human GH (somatropin) treats children's growth disorders and adult GH deficiency.
Metabolic Health: GH contributes to proper bone density, heart muscle function, and healthy cholesterol levels.
Aging Research: Some healthcare providers prescribe GH to the elderly to increase vitality, although the efficacy and safety of this use remain under investigation.