Effects of hydrocortisone on the adrenaline-adenylate cyclase system of the skin.

Using pig skin slices, we investigated the effects of hydrocortisone on the adenylate cyclase system of the skin. In short-term experiments, hydrocortisone, when added singly or in combination with other stimulators of adenylate cyclase in the skin (adrenaline or histamine), had no effect on cyclic AMP accumulation. However, when skin slices were incubated with hydrocortisone for more than 6 h, the response to adrenaline differed, with a greater accumulation of cyclic AMP in the hydrocortisone-treated skin. This effect was seen at a concentration of more than I micrometer hydrocortisone and was most marked 48 h later, while responses to adrenaline in control skin gradually decreased and remained low. Histamine, which is another stimulator of adenylate cyclase of the skin, did not cause a greater cyclic AMP accumulation in response to this hydrocortisone treatment. There was no significant difference in either low Km or high Km cyclic AMP phosphodiesterase activities as a result of this hydrocortisone treatment. Hydrocortisone seems to act by protecting the adrenaline-adenylate cyclase system of the skin.