麻痹性贝毒对学习记忆及肌肉运动耐力影响

Effects of PSP in low level from shellfish on ability of learning and memory and motor activity

目的 探讨低水平摄入麻痹性贝毒（paralytic shellfish poisoning，PSP）对大鼠学习记忆能力、肌肉运动耐力的影响。方法 从市售污染贝类海产品中提取麻痹性贝毒。大鼠随机分为5组，设3个染毒组，2个对照组。高、中、低剂量染毒组灌胃用PSP溶液浓度分别为18．4，9．2和4．6μgSTX／kg。空白对照组为自由饮用水，溶剂对照组为经小鼠检测无毒的贝组织盐酸提取液（0．1mol／L）。各组大鼠每天灌胃1次，染毒剂量每周按体重调整1次。第28，29d进行跳台实验，测试学习记忆能力，第31～34d进行游泳实验。测试肌肉运动耐力情况。结果 高剂量雄性大鼠学习错误次数显著增加，而衡量记忆能力的各项指标则差异无统计学意义；中、高剂量雌性大鼠不仅学习错误次数显著增加，而且衡最记忆能力的潜伏期也显著缩短。高剂量雄性大鼠的游泳时间明显低于对照组。结论 低水平长期摄入PSP毒素对大鼠学习记忆能力及肌肉运动耐力可造成一定程度的损害。

Objective Through the investigations of the paralytic shellfish poisoning（PSP）on ability of learning and memory and motor activity in rats to gain more information on toxicity of PSP. Methods PSP was extracted from the seafood in market, and the toxicity of the extract was determined by mouse bioassay. A total of 50 rats were divided into 5 groups： three PSP-treated groups were fed with the extracts in 18.4μg STX/kg/d（high）, 9.2 μg STX/kg/d（middle）, 4.6 μg STX/kg/d（low）, respectively. Two controls were set, one group was fed with HC1 extracts from no toxic bivalves and the other with nature water. The extracts in different toxicity were administrated to mrs through gastrotube once a day for 35 days. At the 28^th and 29^th day of experiment, changes in ability of learning and memory of rots were investigated by step-down test and that in motor activity were observed through exhaustive swimming test from the 31^st to the 34^th day of experiment. Results For the male rats, a significant increase in number of errors of learning and a decrease in swimming time occurred in the high dose group. For the female rats, the number of errors in learning increased in the middle group and high group, in addition, the incubation period decreased greatly. Conclusion PSP did damage to the motor activity and ability in learning and memory in rats fed with certain PSP.