Inhibitory effect of LM-001 on the biosynthesis of prostaglandin E₂ in carrageenin-induced inflammatory exudate at the rat hind paw

Abstract

Quantities of prostaglandin E₂ (PGE₂) in carrageenin-induced inflammatory exudate at the rat hind paw were measured by the radioimmunoassay method. PGE₂ level increased rapidly and peaked 3 hours after treatment of carrageenin. Intravenous administration of LM-001, indomethacin (IM) and aspirin DL-lysine (VP), given 1 hour after treatment of carrageenin, significantly lowered the PGE₂ level in the exudate (sampled 3 hours after treatment of carrageenin), dose-dependently. ID₅₀ value (95% confidence limits) of each drug was as follows; LM-001: 1.2 (0.2-6.5) mg/kg, VP: 26.9 (4.5-161.2) mg/kg and IM: 0.2 mg/kg (95% confidence limit was impossible to be calculated) . These drugs very significantly reduced the PGE₂ concentration in exudate, but the edema formation was not always suppressed to the same degree of PGE₂ biosynthesis. These findings suggest that antiinflammatory potencies of these drugs are unable to account for only the inhibitory potencies of PGE₂ biosynthesis in this model.