两面针结晶8的解痉和镇痛作用研究

结晶-8,是从两面针提出的一种单体。当浓度为1×10^-6～1×10^-4g/ml对正常离体豚鼠回肠活动无影响,但对乙酰胆硷、匹鲁卡品、氯化钡及组织胺所致肠肌收缩有明显的松弛作用;结晶-8腹腔注射10 mg/kg有明显抑制小鼠扭体反应;8～20 mg/kg明显提高家兔及大鼠痛阈,200μg/kg脑室注射亦有明显提高大鼠痛阈。其镇痛作用不被丙烯吗啡(5 mg/kg)所拮抗,而被利血平(4 mg/kg)所对抗。表明结晶-8的解痉作用直接作用于肠平滑肌。而镇痛作用具有中枢性,与吗啡受体无直接关系,但与脑内单胺类介质有关。

STUDIES ON THE ANTISP ASMODIC AND ANALGESIC ACTIONS OF CRYSTAL-8 ISOLATED FROM ZANTHOXYLUM NITIDUM (ROXB.) DC.

The LD₅₀ of crystal-8, isolated from the root or stem of Zanthoxylum nitidum (Roxb.) DC. was 68.0±8.4mg/kg(i. p.) in mice. The contraction of the ileac muscles of the guinea-pig, induced by acetylcholine, pilocarpine, neostigmine, barium chloride or histamine, was relaxed by Crystal-8 at the concentration of 1×10^-6～1×10^-4g/ml. In mice the writhing induced by 0.1% acetic acid (0.1ml/10g) was antagonized by Crystal-8 (10 mg/kg, i. p). In rabbit the pain threshold, measured by the potassium ionophoresis method, was markedly elevated by intraperitoneal administration of Crystal-8 at the dose of 8 or 16 mg/kg. Marked elevation of pain threshold was also obtained 15 minutes after the administration of 10～20 mg/kg(i.p.)or 200 μg/kg(intraventricular inj.) as measured by the rat tail-flick method. The analgesic effect of Crystal-8 was not antagonized by nalorphine(5mg/kg, i. p.) but antagonized by reserpine (4mg/kg, i.p.).These results indicate that: the antispasmodic effect of Crystal-8 probably was produced by direct action on the smooth muscles; the analgesic effect of Crystal-8 appears to be of a central nature, unrelated to the morphine receptors, but related, to the monoamine transmitters in the brain.