Glucocorticoids such as cortisol, are synthesized in the zona fasciculata.
Cortisol synthesis are under control of the hypothalamic-pituitary-adrenal (HPA) axis.
Glucocorticoids are involved in fuel metabolism, anti-inflmaatory processes, and immunosuppression.
- Glucocorticoids reduce prostaglandin E2 (PGE2) synthesis by inhibiting the activity of phospholipase A2, which is needed to release arachidonic acid from the cell membrane.
- Glucocorticoids block the transcription of the mRNA for the pyrogenic cytokines
Cortisol helps the body respond to stress.
- helps maintain blood pressure and [cardiovascular function;]?
- helps slow the immune systems inflammatory response;
- helps balance the effects of insulin in breaking down sugar for energy; and
- helps regulate the metabolism of proteins, carbohydrates, and fats.
AldosteroneAldosterone - a mineralocorticoid that controls blood pressure is a hormoneHormone - a chemical made by a gland that travels in the bloodstream and "tells organs what to do." made by the adrenal gland that helps control the blood pressure by changing the levels of electrolytes such as sodium and potassium in the blood. Too much aldosterone causes the body to hold onto sodium and water and to get rid of potassium in unsafe amounts. This, in turn increases the amount of fluid in your body, and therefore increases your blood pressure.
Alterations in the Immune Response
The significant rise in circulating cortisol levels affects virtually all aspects of the immune response, including cytokine production, leukocyte trafficking and recruitment, and production of chemokines. Overall, glucocorticoids exert an anti-inflammatory response and increase the risk of infections. CRH may have direct proinflammatory effects on cells of the immune system. Activation of the autonomic nervous system also affects the immune response through effects on neutrophil demargination and cytokine production.
Short-term activation of these stress response mechanisms ensures that energy substrates are available to meet the increased metabolic demands of the individual. However, prolonged duration and increased magnitude of these activities lead to erosion of lean body mass and tissue injury. Nevertheless, impaired activation or lack of responsiveness of the HPA and autonomic nervous system can also be deleterious, as in the case of the critically ill patient. Thus, the overall regulation of the neuroendocrine responses that mediate the physiologic functions involved in maintaining and restoring homeostasis is critically important in situations such as illness, trauma, surgery, or fasting.
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