Mechanism of anti-inflammatory action of glucocorticoids: re-evaluation of vascular constriction hypothesis.

1 The question whether constriction of local vessels is essential for the anti-inflammatory action of glucocorticoids in carrageenin-induced granulomatous inflammation was studied. 2 The vasodilator prostaglandin E1 injection into the granuloma pouch fluid increased the exudation of plasma protein into the granuloma tissue. 3 Noradrenaline significantly reduced plasma exudation, possibly through alpha-adrenoceptor stimulation. 4 Cortisol and dexamethasone in doses sufficient to inhibit vascular permeability were without effect on the blood content in the granuloma tissue. 5 The results suggest that constriction of local vessels does not play an essential role in the anti-exudative effect of glucocorticoids in chronic proliferation inflammation.