EFFECT OF RU-486 ON THE ATROPHOGENIC AND ANTIINFLAMMATORY EFFECTS OF GLUCOCORTICOIDS IN SKIN

Clobetasol-17-propionate (CP), a synthetic glucocorticoid (GC), reduce d skin thickness in rats. Both the subcutaneous injection and topical applications of RU 486 counteracted CP-induced reduction in skin thick ness. Topical application of the CP cream completely inhibited the ear edema produced by croton oil. A less potent GC, hydrocortisone-17-but yrate, also inhibited ear edema, This antiinflammatory effect was not abolished by the subcutaneous injection or topical application of RU 4 86. These observations suggest that GC-induced skin atrophy is mediate d by glucocorticoid receptors (GRs), while the inhibition of croton oi l-induced inflammation by GC is primarily related to the direct effect s of GC, which are not mediated by GRs. Our findings suggest that RU 4 86 inhibits the atrophogenic effect of GCs without interfering with th eir antiinflammatory effect. Dissociation of antiinflammatory and atro phogenic activity of GC seems favorable in treating inflammatory skin diseases lacking epidermal proliferation.