Recording of Inward Rectifying K<sup>+</sup> Currents in Freshly Isolated Basilar Artery Smooth Muscle Cells by Patch Clamp Technique

Cerebrovascular disease is a prevalent condition among the elderly, with its incidence steadily rising. The basilar artery is a critical cerebral vessel that supplies the pons, cerebellum, posterior brain regions, and inner ear. Potassium (K⁺) channel activity plays a significant role in determining vascular tone by regulating the cell membrane potential. Activation of inward rectifying K⁺ (Kir) channels, like other K⁺ channels, leads to cell membrane hyperpolarization and vasodilation. In this study, freshly isolated smooth muscle cells from the basilar artery were used to record Kir currents via the whole-cell patch clamp technique. The effects of 100 µmol/L BaCl2, a Kir channel inhibitor, and 10 µmol/L sodium nitroprusside (SNP), a nitro vasodilator, on Kir channel currents were investigated. The results demonstrated that BaCl2 inhibited Kir channel currents in basilar artery smooth muscle cells, whereas SNP enhanced these currents. This protocol provides a comprehensive guide for preparing freshly isolated arterial smooth muscle cells and recording Kir channel currents using the patch clamp technique, offering a valuable resource for researchers seeking to master this method.