It is produced in many animals, mainly by the zona fasciculata of the adrenal cortex in an adrenal gland.[1] In other tissues, it is produced in lower quantities.[2] By a diurnal cycle, cortisol is released and increases in response to stress and a low blood-glucose concentration.[1] It functions to increase blood sugar through gluconeogenesis, suppress the immune system, and aid in the metabolism of calories.[3] It also decreases bone formation.[4] These stated functions are carried out by cortisol binding to glucocorticoid or mineralocorticoid receptors inside a cell, which then bind to DNA to affect gene expression.[1][5]
^Chyun YS, Kream BE, Raisz LG (February 1984). "Cortisol decreases bone formation by inhibiting periosteal cell proliferation". Endocrinology. 114 (2): 477–80. doi:10.1210/endo-114-2-477. PMID6690287.
^DeRijk RH, Schaaf M, de Kloet ER (June 2002). "Glucocorticoid receptor variants: clinical implications". The Journal of Steroid Biochemistry and Molecular Biology. 81 (2): 103–122. doi:10.1016/S0960-0760(02)00062-6. PMID12137800. S2CID24650907.