Influence of phentolamine, chlorisondamine, 3-[(3-cholamidopropyl) dimethylammonio]-1-propane sulfonate (L-NAME), and nitroprusside on methylene chloride (CH
) fraction-induced hypotensive action in the anesthetized rats. Phentolamine (1 mg/kg), chlorisondamine (1 mg/kg), L-NAME (3 mg/kg/30 min), and sodium nitroprusside (30 μg/kg/30 min) were given intravenously (i.v.), respectively, after obtaining CH2Cl2 fraction-induced hypotensive action. Statistical difference was analyzed by comparing control response with that after treatment with each blockade. **p < 0.01.