The Human Body

Hydrocortisone

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Hydrocortisone, also cortisol, common names for 17-hydroxy-corticosterone, the principal hormone secreted by the outer layer, or cortex, of the adrenal gland. Hydrocortisone affects the metabolism of carbohydrate, protein, and fat; the maturation of white blood cells; the retention of salt and water in the body; the activity of the nervous system; and the regulation of blood pressure. Secretion of hydrocortisone from the adrenal cortex is stimulated by the pituitary hormone ACTH.

Because of their widespread effects, hydrocortisone and related compounds, called corticosteroids, or corticoids, are employed for many medical purposes. They are used to treat a deficiency of adrenal cortical hormones, a condition called congenital adrenal hyperplasia, rheumatoid disease that is not helped by milder drugs, and to counter severe non-infectious inflammations. Corticosteroids suppress the immune response, so they are used to increase acceptance of transplants (Medical Transplantation).

Other conditions for which they are helpful are asthma, collagen diseases, and eye inflammations. Because corticosteroids affect so many body processes, they must be used carefully. Corticosteroids dispose persons to infection and can lead to swelling of the face and limbs, muscle weakness, weight gain, high blood pressure, and diabetes.

Another naturally occurring corticosteroid hormone, called cortisone, was the first corticosteroid to be isolated, in 1935. It was synthesized in 1944 and subsequently became available for widespread medical use. Cortisone is rapidly converted to hydrocortisone in the body. Synthetic corticosteroids with more specific activity have now been made and are preferred in many situations.