adrenocorticotropin, 39 AA, syn as part of larger protein known as proopiomelanocortin (POMC).
disease: congenital adrenal hyperplasia, lack of cortisol because of lack of enzyme 11b-hydroxylase.
treatment: correct deficiency and normalize ACTH secretion.
bind to ACTH recept on memb of middle and lower layer.
cAMP cascade, activate steroidogenic enzyme, increase syn of steroid hormones.
indep of sleep and abolished by stress and Cushing's disease.
Effect of stress of glucocorticoids.
increase the syn and release of CRH, ACTH and cortisol.
advantage: provide energy
disadvantage: cortisol inhibits wound healing
increase blood glucose (diabetes mellitus), decrease immune response, loss of bone.
cortex: lipid epithelial, from mesoderm. produce steroid hormones. glucocorticoids, mineralocorticoids, and progestins.
medulla: chromaffin cells, from neural crest. add potassium bichromate, become fine brown granules. catecholamine epinerphrine and norepinephrine and peptide hormones (enkephalins, dynorphins and atrial natriuretic peptides).
adrenal cortex, 3 layers.
lower: glucocorticoids, progestins, androgen and estrogens.
hypo: addison's. no adrenocortical hormones. atrophy of adrenal glands due to tubreculosis. treat with aldosterone.
hyper: cushing's. too much ACTH. too much glucocorticoids and mineralocorticoids. surgery. lead to osteoporosis.