PKC在有氧运动调控高血压脑动脉平滑肌细胞STOCs中的作用

摘要：蛋白激酶C（PKC）对脑血管张力调节具有重要调控作用，本研究旨在观察PKC在有氧运动调控自发性高血压大鼠（SHR）脑动脉自发性瞬时外向钾电流（STOCs）和大电导钙激活钾（BKCa）通道全细胞稳态电流的作用。方法：急性酶分离脑动脉平滑肌细胞，采用穿孔膜片钳技术记录PKC对各组STOCs和BKCa通道全细胞稳态电流的影响。结果：1）与正常血压组相比，高血压组中PKC对STOCs幅值和频率的抑制作用显著增强；2）有氧运动可显著降低高血压组PKC对STOCs的抑制作用；3）与正常血压组相比，高血压组中PKC对BKCa通道全细胞稳态电流的增强作用显著升高；4）有氧运动可显著降低PKC对高血压组BKCa通道全细胞稳态电流的增强作用，同时显著提高PKC对正常血压组BKCa电流的作用。结论：1）高血压时大脑中动脉平滑肌细胞经PKC/LTCCs/Ca2+/STOCs/LTCCs/Ca2+/STOCs信号通路对STOCs的增强作用大于经PKC/STOCs途径对STOCs的抑制作用，故STOCs在高血压时总体表现为病理性上调；2）PKC对高血压STOCs的抑制作用增强，这将进一步加剧高血压病理发展，而长期规律的有氧运动可显著改善以上病理进程。

Effects of PKC on the Aerobic Exercise Induced Regulation of STOCs in Cerebral Arteries from Spontaneously Hypertensive Rats

Abstract: Objective: Protein kinase C (PKC) plays an important role in the regulation of cerebrovascular tension. The purpose of this study was to observe the effect of PKC on spontaneous transient outward currents (STOCs) and the whole-cell BKCa currents in cerebral artery smooth muscle cells (CASMCs) that were regulated by aerobic exercise. Methods: CASMCs were isolated by enzyme, and the effects of PKC on STOCs and the whole-cell BKCa currents were measured by perforated patch clamp. Results: 1) PKC inhibited the amplitude and frequency of STOCs, meanwhile these effects were significantly higher in SHR-SED than in WKY-SED. 2) Aerobic exercise significantly attenuated the inhibition of PKC on STOCs in spontaneous hypertension group. 3) PKC unregulated the amplitude of the whole-cell BKCa currents, meanwhile these effects were significantly higher in SHR-SED than in WKY-SED. 4) Aerobic exercise significantly attenuated the upregulation of PKC on the whole-cell BKCa currents in SHR, moreover enhanced these effects in WKY. Conclusion: 1) In SHR, the enhancement effect of CASMCs on STOCs through PKC/LTCCs/Ca2+/STOCs/LTCCs/Ca2+/STOCs pathway is greater than inhibiting effect of those on STOCs through PKC/STOCs pathway, so STOCs in hypertension is histopathologically up-regulated. 2) The inhibiting effects of PKC on STOCs is enhanced in SHR, which aggravates the process of hypertension; however, long-term regular aerobic exercise can efficiently ameliorate this pathological change and restore cerebral arterial function.