Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and th...Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and the medial region containing intracardiac ganglia was isolated and cut into pieces. For preparation of paratracheal neurons, the tracheas were removed and the superficial membranous layer containing paratracheal ganglia was rapidly isolated. Intracardiac and paratracheal ganglion neurons were dissociated after digestion by collagenase and trypsin. Whole-cell patch clamp recording was used to identify the pharmacological properties of P2X receptors in cultured neurons. Results：Neurons from these two ganglia responded to ATP with a rapidly activating, sustained inward current, αβ-meATP failed to evoke any re- sponses in paratracheal ganglion neurons while a few of intracardiac ganglion neurons responded to αβ- meATP with a tiny sustained inward current. ADP and UTP had no effect on intracardiac neurons. Lowering pH potentiated ATP responses in neurons from these two ganglia whereas increasing pH inhibited ATP responses. Co-application of Zn^2＋ potentiated ATP responses in intracardiac and paratracheal ganglion neurons. Conclusion： The receptor subtypes involved in intracardiac and paratracheal ganglia appear to be homomeric P2X2, while heteromeric P2X2/3 could not be completely excluded from intracardiac neurons.展开更多
文摘目的:观察内环境因素(pH和甘氨酸及离子浓度)对依达拉奉抗神经元缺血性损伤作用的影响。方法:大鼠原代培养皮质神经元,在不同的实验溶液(模拟缺血后脑内环境的变化)以缺氧缺糖(oxygen-g lucose deprivation,OGD)3 h和再灌12 h诱导皮质神经元损伤,以噻唑蓝(MTT)还原反应和乳酸脱氢酶(LDH)释放观察损伤变化。观察不同实验溶液对抗脑缺血药物依达拉奉抗缺血性损伤作用的影响。结果:在弱碱性(pH 7.8)或含甘氨酸(10μm o l/L)的实验溶液中,OGD损伤加重;在弱酸性(pH 6.5)或高M g2+(1.8 mm o l/L)条件下,OGD损伤减轻。依达拉奉(1μm o l/L)能逆转在pH 6.1、7.4、7.8或含甘氨酸溶液中OGD损伤;而对pH 6.5、高M g2+或低Ca2+溶液中的OGD损伤未显示保护作用。结论:内环境因素改变可影响缺血性损伤程度和依达拉奉抗损伤作用。
基金Supported by the National Natural Foundation of China (No. 30570597)
文摘Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and the medial region containing intracardiac ganglia was isolated and cut into pieces. For preparation of paratracheal neurons, the tracheas were removed and the superficial membranous layer containing paratracheal ganglia was rapidly isolated. Intracardiac and paratracheal ganglion neurons were dissociated after digestion by collagenase and trypsin. Whole-cell patch clamp recording was used to identify the pharmacological properties of P2X receptors in cultured neurons. Results：Neurons from these two ganglia responded to ATP with a rapidly activating, sustained inward current, αβ-meATP failed to evoke any re- sponses in paratracheal ganglion neurons while a few of intracardiac ganglion neurons responded to αβ- meATP with a tiny sustained inward current. ADP and UTP had no effect on intracardiac neurons. Lowering pH potentiated ATP responses in neurons from these two ganglia whereas increasing pH inhibited ATP responses. Co-application of Zn^2＋ potentiated ATP responses in intracardiac and paratracheal ganglion neurons. Conclusion： The receptor subtypes involved in intracardiac and paratracheal ganglia appear to be homomeric P2X2, while heteromeric P2X2/3 could not be completely excluded from intracardiac neurons.
