巯基化合物对杀虫单、沙蚕毒和巴丹急性中毒的解毒作用

ANTIDOTAL EFFECT OF SULFHYDRYL COMPOUNDS AGAINST ACUTE POISONING OF SCD,NEREISTOXIN AND PADAN

国内广用的杀虫单(SCD)和巴丹(pa-dan)是沙蚕毒(NTX)系新杀虫剂。采用麻醉兔腓总神经胫前肌标本,分别iv SCD、NTX和padan后,其间接刺激所激发的胫前肌收缩先显示短时的轻度增加,随后变小,最终消失;呼吸变弱,最后停止。

The insecticides SCD andpadan widely used in China, are nereistoxinderivatives. In nervus peronaeus communis-mus-culus tibialis anterior preparations of urethaneanesthetized rabbits, SCD, NTX and padancompletely depressed the indirectly elicitedtwitch tension but not the directly elicitedone. NTX but not SCD or padan blocked theindirectly elicited twitch tension of isolatedrat diaphragm and frog musculus gastrocnemius.The neuromuscular blockade induced bySCD and NTX could be antagonized by ne-ostigmine and 4-aminopyridine. These pesticideshad little or no effect on arterial blood pres-sure and discharge of nervus phrenicus of rab-bits.The results indicated that the poisoned rab-bits died of respiratory paralysis followingthe neuromuscular blockade. Sodium dimercaptopropanesulphonate(Na-DMPS) and sodium dimercaptosuccinate(Na-DMS) were shown to be the effective an-tidotes for acute poisoning of SCD, NTX andpadan. In mice, Na-DMPS and Na-DMS (250and 1000 mg/kg, respectively, ip 20 min beforeSCD) increased LD50 of ig SCD from 85.7 to346.4, 261.9 mg/kg, respectively Prior to igpadan, ip Na-DMPS 250 mg/kg also increased LD_(50) from 125.5 to 370.0 mg/kg. The the-rapeutic effect of Na-DMPS was also de-monstrated in SCD-poisoned consciou s rabbits. Na-DMPS and Na-DMS comp letely an-tagonized the neuromuscular blockade and res-piratory depression induced by these agents inrabbits. The antagonism of SCD-induced neu-romuscular blockade by 1-cysteine (400 mg/kg.iv) was less effective and of shorter duration.IM 50 mg/kg of dimercaprol showed little eff-ect. In rabbits pretreated with Na-DMPS, nochanges of muscle twitch tension to direct orindirect stimulation were observed. Na-DMPSdid not antagonized the neuromuscular blo-ckade of a-tubocurarine. Perhaps sulfhydrylcompounds might react with these pesticidesin vivo. It is expected Na-DMPS and Na-DMSmay be clinically useful in treatment of theseinsecticides poisoning. Sodium smmonium 2-dimethylamino-1,3-propane-dithiosulfate