Antagonistic effects of 6 drugs on myopathy induced by soman intoxication

When the diaphragm of rat intoxicated by soman (2 vg/10 vl) locally. myopathy developed at the area of motor end plates 15 min after poisoning. The characteristics of morphological changes were focal degeneration and necrosis of muscular fibres at the motor end plates, involving swelling of mitochondria. dilation of sarcoplasmic reticulum and disappearance of Z lines. etc. The myopathy was completely controlled by im HI-6 (bispyridinium oxime, 10 mg/kg) immediately after soman poisoning or by pretreatment of im neomycin (100 mg/kg, -60 min) combined with im gallamine triethiodide (10 mg/kg, -15 min). Obidoxime im (10 mg/kg, 0 min), hemicholine im (0.2 mg/kg, - 1.20 min) or iv MgS04 (40 mg/kg. -2 min) decreased the incidence of myopathy. At the motor end plates the rate of positive Ca2+ dyeing was correjated with the incidence of myopathy. r = 0.90.