The effects of adrenalectomy and corticosterone on vascular permeability responses in the skin of the rat.

The vascular permeability response induced in the rat by intracutaneous histamine or serotonin is noticeably influenced by previous adrenalectomy or treatment with corticosterone. Permeability responses were demonstrated by the local exudation of circulating Evans blue at sites of intracutaneous injection of the above permeability factors, the intensity of the responses being assessed by the diameter of the blue lesions as well as by the amount of exuded dye. In adrenalectomized rats maintained for 72-80 h on 0-9% solution of NaCl, the permeability response to histamine was enhanced about 10-fold, that to serotonin about 5-fold. When rats were given subcutaneous corticosterone, 1-0 mg/animal 1 h before testing, the responses to the same 2 permeability factors were decreased about 10-fold and 5-fold respectively. Corticosterone also decreased the enhanced responses in adrenalectomized rats to levels somewhat below those in mock adrenalectomized controls. The results support the proposal from other work that vascular exudation in experimental inflammation is regulated by an anti-inflammatory factor that accumulates in injured tissues and owes its effect to release of corticosteroids.