THE PHARMACOLOGICAL ACTION OF SINOMENINE ON THE CENTRAL NERVOUS SYSTEM

The intraperitoneal injection of sinomenine at a dose of 20-40 mg/kg did not signi- ficantly potentiate the pentobarbital narcosis in mice. Administration of sinomenine 12.5-50 mg/kg markedly reduced the spontaneous activity (photocell cage method) and passive activity (rotating rod method) within 20 minutes. Sinomenine also aggravated the strychnine-convulsion in mice, but the metrazol-con- vulsion was not affected. Intravenous injection of sinomenine 5 mg/kg produced emesis in one of four dogs employed in the experiment. The emesis induced by intravenous injection of apomorphine 0.05 mg/kg was not affected by pretreatment of sinomenine. In rats, intraperitoneal injection of sinomenine 60 mg/kg produced a slight hypother- mia within 30-120 minutes. The subcutaneous LD₅₀ of sinomenine in mice was 535±41.9 mg/kg.