摘要
目的 观察氰戊菊酯、辛硫磷农药单用和混用对成年大鼠背根神经节 (DRG)神经元钠通道的毒性作用。方法 应用膜片钳技术研究氰戊菊酯和辛硫磷对DRG河豚毒素敏感 (TTX S)和不敏感 (TTX R)型钠通道的作用。结果 氰戊菊酯明显延迟去极化时TTX R型钠通道的关闭时间 ,氰戊菊酯 10、5 0、10 0 μmol/L组和对照组钠通道峰电流失活时间常数分别为 (8 10± 2 41)ms、(11 78±2 76 )ms、(8 76± 1 94)ms和 (6 41± 1 32 )ms。氰戊菊酯还具有延长TTX R型钠通道尾电流的关闭时间 ,氰戊菊酯 10、5 0、10 0 μmol/L组和对照组尾电流失活时间常数分别为 (6 11± 0 5 2 )ms、(7 82±0 82 )ms、(7 2 3± 1 0 9)ms和 (4 91± 0 97)ms。氰戊菊酯对TTX S型钠通道的作用小于TTX R型 ,仅表现为对尾电流的关闭有延迟作用。辛硫磷对这两种亚型钠通道无明显影响 ,将氰戊菊酯和辛硫磷混配使用后 ,仅见氰戊菊酯作用的表现 ,未见氰戊菊酯和辛硫磷的联合作用。结论 氰戊菊酯影响DRG钠通道峰电流和尾电流 ,对TTX R型钠通道的作用大于TTX S型 。
Objective To study the joint neurotoxic effects of phoxim (Pho) and fenvalerate (Fen) on tetrodotoxin sensitive (TTX S) and tetrodotoxin resistant (TTX R) Na + currents in dorsal root ganglion (DRG) neurons of adult rat. Methods Whole cell patch clamp technique was used to test the effects of Pho and Fen on TTX S and TTX R sodium currents in DRG neurons. Results The inactivation of TTX R sodium channel was obviously slowed down by Fen. The τ Na of peak currents at doses of 10, 50 and 100 μmol/L Fen and control groups were (8 10±2 41) ms, (11 78±2 76) ms, P <0 01, (8 76±1 94) ms, P <0 05 and (6 41±1 32) ms respectively. The inactivation of TTX R sodium channel tail currents was also significantly delayed by Fen. The τ Na of the tail currents at doses of 10, 50, 100 μmol/L Fen and control groups were 6 11±0 52 ( P<0 05 ), 7 82± 0 82 ( P <0 05), 7 23±1 09 ( P <0 05) and (4 91±0 97) ms separately. As compared with TTX R sodium channel, the TTX S sodium channel was less responsive to Fen exposure, which only led to slowly decay TTX S sodium tail currents. There was no any effect of Pho on the TTX S and TTX R sodium channels. The mixed treatment of a Pho and Fen did not show joint effect on the sodium currents. Conclusion Both the peak and tail currents are changed by Fen, however, Fen has more remarkable effects on TTX R than on TTX S sodium channel. The combined exposure to Pho and Fen shows no joint effect on the sodium channel.
出处
《中华预防医学杂志》
CAS
CSCD
北大核心
2000年第3期136-139,共4页
Chinese Journal of Preventive Medicine
基金
九五"国家医学科技攻关项目 ( 96 90 6 0 4 11)
江苏省教委自然科学基金!(JW970 111)
江苏省卫生厅科技发展基金!(H9716)
关键词
钠通道
混配农药中毒
大鼠
背根神经节
Organothiophosphorus compounds
Pyrethrins
Ganglia, Spinal
Sodium channels
