Evaluation on neurotoxicity using dissociated mammalian CNS neurons

采用膜片钳技术和流式细胞术观察了三苯基锡对游离大鼠脑神经元和小鼠胸腺细胞的影响。三苯基锡通过抑制失活过程增加了电压依赖性Na^+电流的电流幅值，并降低了脑神经元中电压依赖性K^+电流（延迟和瞬态K^+电流）。此外，三苯基锡通过增加细胞膜Ca^<2+>的通透性和从脑细胞和胸腺细胞的细胞内钙储存中释放Ca^<2+>来增加细胞内Ca^<2+>浓度。因此，三苯基锡可能引起哺乳动物中枢神经系统的高兴奋性。三丁基锡对细胞内Ca^<2+>浓度具有相似的作用，而二苯基锡、一苯基锡、二丁基锡和一丁基锡则没有这种作用。

Effects of triphenyltin were examined on dissociated rat brain neurons and mouse thymocytes using patch clamp technique and flow-cytometric technique. Triphenyltin increased the current amplitude of voltage-dependent Na^+ current by inhibiting the inactivation process,associated with decreasing the voltage-dependent K^+ currents(delayed and transient K^+ currents),in brain neurons. Futhermore, triphenyltin increased the intracellular Ca^<2+> concentration by increasing the membrane Ca^<2+> permeability and releasing Ca^<2+> from the intracellular calcium stores in both brain neurons and thymocytes. Therefore,triphenyltin may cause hyperexcitability on mammalian CNS. Tributyltin possessed similar actions on the intracellular Ca^<2+> concentration while it was not the case for diphenyltin,monophenyltin, dibutyltin and monobutyltin.