Modification of cholesterol crystal-induced inflammation.

Cholesterol crystals induced inflammation in normal rats upon being injected into the footpad. Cholesterol caused less swelling than did an equal amount (3 mg) of monosodium urate crystals. In rats made deficient in essential fatty acids on the basis of clinical criteria (thereby presumably being deficient in prostaglandins) cholesterol crystals did not produce normal levels of swelling. Injections of prostaglandin E1, prostacyclin and thromboxane (B2) did not result in perturbations in cholesterol-induced swelling. Colchicine and indomethacin, given systemically, were very effective in reducing cholesterol crystal-induced foot swelling. Prostaglandin E2 also demonstrated an anti-inflammatory effect.