Anti-inflammatory action of progesterone on carrageenin-induced inflammation in rats.

Effect of progesterone (1 mg/kg) on the inflammation in rats induced by carrageenin was studied. Progesterone inhibited the vascular permeability and the formation of granulation tissue in the early phase of the inflammation. In the chronic proliferative phase, progesterone suppressed the vascular permeability and there was an active resorption of the granulation tissue. Increased degradation of noncollagen protein was observed in the treated group without apparent influence on the metabolism of collagen or on the synthesis of noncollagen protein. The mode of action of progesterone was compared with that of a potent anti-inflammatory steroid, hydrocortisone acetate.