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本研究旨在观察蛋白激酶C(protein kinase C,PKC)是否参与了肠淋巴管结扎或肠淋巴液引流对失血性休克大鼠血管钙敏感性的调节作用。Wistar雄性大鼠分为假手术组(Sham)、失血性休克组(Shock)、休克+肠淋巴管结扎组(Shock+Ligation,休克手术前行肠淋巴管结扎)、休克+肠淋巴液引流组(Shock+Drainage,休克手术前行肠淋巴液引流),在休克3h时间点,分离出肠系膜上动脉(superior mesenteric artery,SMA)组织,检测PKC蛋白水平与磷酸化PKC(p-PKC)活性;制备SMA血管环,检测各组SMA血管环对梯度[Ca2+]的敏感性,其指标包括收缩性、最大收缩力(Emax)和50%最大反应时的[Ca2+]负对数(pD2),另取Shock+Ligation与Shock+Drainage组SMA血管环分别与PKC调节剂PMA和Staurosporine孵育后,观察钙敏感性变化。结果显示,Shock组SMA的PKC水平、p-PKC活性、对梯度[Ca2+]的收缩性均显著低于Sham组,而Shock+Ligation组与Shock+Drainage组的以上指标均显著高于Shock组。PKC激动剂PMA提高了Shock+Ligation和Shock+Drainage组大鼠SMA血管环对梯度[Ca2+]的收缩性与Emax值;而PKC抑制剂Staurosporine则显著降低了Shock+Ligation和Shock+Drainage组大鼠SMA血管环对梯度[Ca2+]的收缩性和Emax值。以上结果提示,PKC参与了阻断肠淋巴液回流对休克大鼠血管钙敏感性的增强作用。
This study aimed to observe whether protein kinase C (PKC) is involved in regulation of vascular calcium sensitivity in hemorrhagic shock rats by intestinal lymphatic ligation or intestinal lymph drainage. Wistar male rats were divided into Sham group, Shock group, Shock + Ligation group, intestinal lymphatic vessel ligation before shock operation, shock + intestinal lymph drainage group (Shock + Drainage, intestinal lymph drainage before shock surgery). At 3h after shock, the superior mesenteric artery (SMA) tissue was isolated and the PKC protein level and p-PKC activity were detected. SMA rings were prepared and their sensitivity to gradient [Ca2 +] was evaluated. The indices included contractility, maximal contractile force (Emax) and negative logarithm of [Ca2 +] at 50% maximal response The Shock + Ligation and Shock + Drainage groups of SMA vascular rings were incubated with PKC regulators PMA and Staurosporine to observe changes in calcium sensitivity. The results showed that PKC level, p-PKC activity and contractility of gradient Ca2 + in Shock group were significantly lower than those in Sham group, while those in Shock + Ligation group and Shock + Drainage group were significantly higher than Shock group. PKC agonist PMA increased Shock + Ligation and Shock + Drainage rats’ SMA vasoconstriction gradient and Emax value of gradient [Ca2 +]; while PKC inhibitor Staurosporine significantly reduced the Shock + Ligation and Shock + Drainage rats Shrinkage and Emax values of SMA vascular rings for gradient [Ca2 +]. The above results suggest that PKC is involved in the enhancement of calcium sensitivity in shock rats by blocking intestinal lymph reflux.