Temporary increases in cortisol can enhance immune function.

a. True

b. False

The right answer is False

Cortisol is a steroid hormone produced from cholesterol and secreted by glands located above the kidneys (adrenocortical glands). Its secretion is dependent on another hormone, ACTH produced by the pituitary gland in the brain (ACTH for adrenocorticotrophin).

Cortisol plays several roles in the body, and participates in an immunosuppressive action by inhibiting the transcription factor NF-kB (NF-kappaB) : stress activates first NF-kB. This NF-κB could then stimulate the production and secretion of inflammatory mediators such as cytokines. Ultimately, elevated cortisol levels may rapidly reduce the inflammatory response. However, in cases of adrenal exhaustion, low levels of cortisol are chronic. An excessive immune response following stress (physical or psychological) may then occur, caused by improper inhibition of NF-kB activation.