Alterations in the Expression of ATP-Sensitive Potassium Channel Subunit mRNA after Acute Peripheral Nerve and Spinal Cord Injury

Abstract

ATP-sensitive potassium channels (K_ATP) are involved in the regulation of potassium homeostasis in the nervous system, and they may play an important role in acute peripheral nerve and spinal cord injury. Here, the expression of the K_ATP genes was monitored by reverse transcription polymerase chain reaction (RT-PCR) in the rat dorsal root ganglion, spinal cord and cerebral cortex following acute sciatic nerve and spinal cord injury. Electrophoresis of the RT-PCR products showed that in comparison with the normal rats, the K_ATP mRNA expression level was up-regulated for the Kir6.2 subunit in the rat dorsal root ganglion 4 and 24 h after the acute sciatic nerve injury (142.7 ± 23.0 and 135.5 ± 21.0%, p < 0.05, vs. control, n = 3), and both Kir6.1 and sulphonylurea receptor 2 mRNA were increased in the spinal cord during the same time period after the acute spinal cord injury (266.5 ± 67.1 and 248.7 ± 67.7%; 145.1 ± 42.6 and 152.6 ± 44.3%, p < 0.05, vs. control, n = 3). No significant changes of K_ATP genes were observed in the cerebral cortex among both sciatic-nerve- and spinal-cord-injured animals. These results suggest that acute peripheral nerve and spinal cord injury provoke different regulations of K_ATP gene expression in the peripheral and central nervous system.