Cortisol ELISA

Cortisol is a steroid hormone released from the
adrenal cortex in response to a hormone
called ACTH (produced by the pituitary gland), it is
involved in the response to stress; it increases blood
pressure, blood sugar levels, may cause infertility in
women, and suppresses the immune system.
Cortisol acts through specific intracellular receptors
and has effects in numerous physiologic systems,
including immune function, glucose-counter
regulation, vascular tone, substrate utilization and
bone metabolism. Cortisol is excreted primarily in
urine in an unbound (free) form.
Cortisol is bound, in plasma, from corticosteroid- binding globulin (CBG, transcotin), with high affinity,
and from albumin. Only free cortisol is available to
most receptors.
The amount of cortisol present in the serum
undergoes diurnal variation, with the highest levels
present in the early morning, and lower levels in the
evening, several hours after the onset of sleep.
Highest levels are at about 6-8 a.m. and lowest levels
are at about midnight. These normal endogenous
functions are the basis for the physiological
consequences of chronic stress - prolonged cortisol
secretion causes muscle wastage, hyperglycaemia, and suppresses immune / inflammatory responses.
The same consequences arise from long-term use of
glucocorticoid drugs.