Study on mechanism of reproductive toxicity and neurotoxicity of 1-bromopropane, a new alternative to chlorofluorocarbons

(1) 1-溴丙烷的毒性机制研究将44只Wistar雌性大鼠分为4组，每组11只，每天8小时，连续12周暴露于浓度为200ppm、400ppm和800ppm的1-溴丙烷中。对照组只呼吸新鲜空气。结果表明：1)四肢肌力减弱，2)大鼠尾远潜伏期延长，3)运动神经传导速度减慢，4)周围神经髓鞘变性，5)延髓细核末梢轴突肿胀，6)肌纤维带带不规则，7)附睾精子减少，8)精子活力下降，9)未成熟头精子增多，10)受精后阶段19步精子增多。研究表明，1-溴丙烷具有严重的剂量依赖性神经毒性，也会损害精子。(2) 1-溴丙烷暴露大鼠脑生化研究32只Wistar雄性大鼠分为4组，每天8小时连续7天暴露于浓度为200ppm、400ppm和800ppm的1-溴丙烷环境中。脑、小脑、脑干和脊髓总肌酸激酶活性降低。大脑和小脑的非蛋白游离SH碱降低，总谷胱甘肽显著降低。(3) 1-溴丙烷暴露生物标志物的研究（与美国Vanderbilt University的Dr.Valentine合作研究）收集29名1-溴丙烷暴露工人的尿液。尿样酸化后用乙酸乙酯提取。n -乙酰s -丙基半胱氨酸是1-溴丙烷的主要代谢物。这可能是1-溴丙烷暴露的一个很好的指标。

(1) STUDY ON TOXIC MECHANISM OF 1-BROMOPROPANE Forty-four Wistar female rats were divided into four groups of elevens and exposed to 1-bromopropane at 200 ppm, 400 ppm and 800 ppm, for eight hours per day for twelve weeks. The control was given only fresh air. Results were as follows : 1) weakened muscle strength of limbs, 2) elongation of distal latency of rat tail, 3) decrease in motor nerve conduction velocity, 4) degeneration of myelin of peripheral nerve, 5) swelling of preterminal axons in gracile nucleus in medulla oblongata, 6) irregular banding of muscle fibers, 7) decreased epididymal sperm, 8) decreased motility of sperm, 9) increase in sperm with immature head, and 10) increased step 19 spermatid at post spermiation stages. The study shows that 1-bromopropane has severe dose-dependent neurotoxicity and also impairs spermiation.(2) BIOCHEMICAL STUDY ON BRAIN OF RATS EXPOSED TO 1-BROMOPROPANE Thirty-two Wistar male rats were divided into four groups and exposed to 1-bromopropane at 200, 400 and 800 ppm, eight hours per day for seven days. Total creatine kinase activity decreased in cerebrum, cerebellum, brainstem and spinal cord. Non protein free SH base decreased and total glutathione significantly decreased at cerebrum and cerebellum.(3) STUDY ON BIOMARKER OF 1-BROMOPROPANE EXPOSURE (a cooperative study with Dr.Valentine, Vanderbilt University, USA) Urine was collected from 29 workers exposed to 1-bromopropane. The urine sample was acidified and extracted with ethyl acetate. N-acetyl S-propylcystein was found as a major metabolite of 1-bromopropane. This might be a good indicator of 1-bromopropane exposure.