Final answer:
Growth Hormone (GH) is a metabolic hormone produced by the anterior pituitary gland that plays a crucial role in growth and development. It operates through direct and indirect actions without functioning as a tropic hormone, unlike other anterior pituitary hormones. GH's release is regulated by the hypothalamus via GHRH and GHIH, with a feedback mechanism maintaining balance.
Step-by-step explanation:
Growth Hormone (GH), also known as somatotropin, is a metabolic hormone produced by the anterior pituitary gland. It consists of a protein made up of 191 amino acids and has a significant role in the growth and development of the human body. GH stimulates protein synthesis and tissue building, functioning through both direct and indirect mechanisms. Unlike some other pituitary hormones, it does not act as a tropic hormone but targets somatic tissues directly alongside its mediation through insulin-like growth factors (IGFs).
Furthermore, GH significantly differs from other pituitary hormones. For example, TSH, ACTH, FSH, and LH are tropic hormones that influence the function of other endocrine glands. In contrast, GH, alongside prolactin, has significant direct effects on the growth and metabolic processes within the body. The indirect action of GH involves mediating insulin-like growth factors that promote the uptake of amino acids and the formation of new proteins, essential for tissue growth, particularly in skeletal muscle and cartilage.
The production and release of GH are regulated by two hypothalamic hormones: growth hormone-releasing hormone (GHRH) and growth hormone-inhibiting hormone (GHIH), also known as somatostatin. The release of these hormones is, in turn, controlled through a negative feedback mechanism that ensures the balance of growth hormone levels in the body.