Normal Physiology of ACTH and GH Release in the Hypothalamus and Anterior Pituitary in Man

摘要: This chapter summarizes the intimate relationship between hypothalamus and anterior pituitary with respect to secretion of ACTH GH from physiological viewpoint. Other chapters in Endotext cover hormones prolactin, LH, FSH, TSH posterior pituitary. Adrenocorticotropic hormone (ACTH) growth (GH) are both peptide secreted is derived cleavage precursor pro-opiomelanocortin (POMC) by prohormone convertase enzymes. Classically, it activates production release cortisol zona fasciculata adrenal cortex via melanocortin receptor MC2R. The major hypophysiotropic factor controlling expression corticotropin-releasing (CRH), conjunction arginine vasopressin (AVP). Key features hypothalamo-pituitary-adrenal (HPA) axis discussed, including ultradian pulsatility CRH, AVP secretion, circadian pattern negative feedback on HPA axis, stress response, effects aging gender. mainly somatotrophs but also expressed other parts brain. Similarly, ACTH, pulsatile diurnal variation, under a auto-regulatory loop, can be affected various factors. Activities that affect include sleep exercise, physical stresses such as fasting hypoglycemia, hyperglycemia, hypovolemic shock surgery. demonstrates differences sexes, male ‘pulsatile’ versus female ‘continuous’ secretion. In addition, level declines age, phenomenon termed ‘somatopause’. All these discussed detail this chapter. For complete coverage all related areas Endocrinology, please visit our on-line FREE web-text, WWW.ENDOTEXT.ORG