论文部分内容阅读
For exploring the phenotypic characteristics of ATP-activated currents in the neurons of rat nodose ganglion associated with genotypic assemply of P2X purinoceptors,experiments were performed using whole-cell patch clamp technique It was shown that:①The majority (312/444,70.3%) of NG neurons responded to ATP (3× 10-5-3× 10-3 mol/L) applied externally with a manner of concentration-dependence.Based on kinetic and morphological features four types of distinct ATP-activated currents were classified:F-(fast),I-(intermediate),S-(slow) and vS-(very slow) types; ② The EC50s of the four concentration-response curves tend to be identical (5.86× 10-5 M、5.92× 10-5 M、3.67× 10-5 M and 4.34× 10-5 M,respectively); ③ The time course of activation (τtact) of the four distinct ATP-activated currents were as follows:fast:(37.6±4.7) ms; intermediate:(104.0± 10.4) ms; slow:(169.4±22.7) ms;very slow:(206.8±26.7) ms,and that of desensitization rate of currents (τdes) were (110.4+±11.5) ms,(1004.6+80.2) ms,(3299.7±27.5) ms and > 1min respectively; ④ From the current-voltage relationship,it can be seen that the reversal potential value of the slow type of the ATP-activated current was 0 mV.