(kôr'tĭsōn´´), steroid hormone whose main physiological effect is on carbohydrate metabolism. It is synthesized from cholesterol in the outer layer, or cortex, of the adrenal gland under the stimulation of adrenocorticotropic hormone (ACTH). Cortisone is classed as a glucocorticoid with cortisol and corticosterone; its effects include increased glucose release from the liver, increased liver glycogen synthesis, and decreased utilization of glucose by the tissues. These actions tend to counter the effects of insulin and may aggravate or mimic diabetes in sufficiently high doses. Cortisone also exerts an effect on salt retention in the kidneys similar to that of aldosterone, although it is not as potent. The hormone causes increased breakdown of proteins and decreased protein synthesis, and large doses given over a long period of time may result in inhibited growth in children or weakening of bones and wasting of muscles in adults.
The principal medical use of cortisone comes from its anti-inflammatory and antiallergic effects; it is extremely useful in the treatment of innumerable diseases including asthma and other allergic reactions, arthritis, and various skin diseases. Cortisone is necessary to maintain life and enable the organism to respond to stress; failure of the adrenal glands to synthesize cortisone (Addison's disease) or surgical removal of the adrenals is fatal unless cortisone is given as replacement therapy. Although less cortisone is manufactured in the body than either cortisol or corticosterone and although cortisone is less potent than cortisol, the term cortisone is often used collectively to include the other glucocorticoids, both the naturally occurring and the synthetic compounds such as prednisone. Small quantities of cortisone were first isolated from animal adrenals in 1935–36. A method of manufacture, involving laboratory synthesis from an acid of bile, was developed, and in 1949 cortisone was first offered commercially. The specific mechanisms by which cortisone and similar compounds act are still poorly understood.