ATP-sensitive potassium channels in rat primary afferent neurons: the effect of neuropathic injury and gabapentin

ATP-sensitive potassium (K-ATP) currents were examined in dorsal root ganglion neurons from neuropathic and control rats using whole-cell voltage clamp recordings. K-ATP channel openers (diazoxide and pinacidil) enhanced, and the blocker glibenclamide inhibited an outward current in control neurons in a manner dependent on the pipette ATP concentration. Analysis of reversal potentials showed that this current is carried by K+ ions. Outward current in cells from rats with peripheral nerve injury was not sensitive to modulators of K-ATP channels. Gabapentin, a putative K-ATP channel opener, had minimal effect on currents in either group of neurons. We conclude that normal primary afferent neurons express K-ATP channels that conduct current which is eliminated by peripheral nerve injury. Gabapentin does not affect this current significantly. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.