Department of Anesthesiology, Samsung Changwon Hospital, Sungkyunkwan University of Medicine, Changwon, Republic of Korea.
Eur J Pharmacol. 2012 Feb 29;677(1-3):131-7. doi: 10.1016/j.ejphar.2011.12.023. Epub 2011 Dec 27.
Levobupivacaine is a long-acting amide local anesthetic that intrinsically produces vasoconstriction both in vivo and in vitro. Levobupivacaine increases intracellular calcium concentrations (Ca(2+)) in vascular smooth muscle cells. The goals of this in vitro study were to investigate whether levobupivacaine-induced contraction is associated with increased Ca(2+) sensitivity and to identify the protein kinases involved in mediating contraction in response to levobupivacaine in isolated rat aortic smooth muscle. The effect of levobupivacaine and potassium chloride (KCl) on the Ca(2+) and tension was measured simultaneously with acetoxymethyl ester of fura-2-loaded aortic strips. Cumulative levobupivacaine concentration-response curves were generated in the presence or absence of the following antagonists: GF 109203X; Y-27632; genistein; SP600125; PD 98059; and SB 203580. Levobupivacaine-induced protein kinase C (PKC), extracellular signal-regulated kinase (ERK), and c-Jun NH(2)-terminal kinase (JNK) phosphorylation and Rho-kinase (ROCK-2) membrane translocation were detected in rat aortic vascular smooth muscle cells using Western blotting. The slope of the Ca(2+)-tension curve for levobupivacaine was higher than that for KCl. Y-27632, GF 109203X, and SP600125 attenuated levobupivacaine-induced contraction in a concentration-dependent manner. Genistein, PD 98059, and SB 203580 attenuated levobupivacaine-induced contraction. Pretreatment with GF 109203X and Y-27632 inhibited levobupivacaine-induced PKC phosphorylation and Rho-kinase (ROCK-2) membrane translocation, respectively. Pretreatment with SP600125 or PD 98059 attenuated the levobupivacaine-induced phosphorylation of JNK and ERK, respectively. These results indicate that levobupivacaine-induced contraction involving an increase in myofilament Ca(2+) sensitivity involves the primary activation of Rho-kinase-, PKC-, and JNK-mediated pathways of rat aortic smooth muscle.
左旋布比卡因是一种长效酰胺类局部麻醉剂，在体内和体外均具有固有血管收缩作用。左旋布比卡因增加血管平滑肌细胞细胞内钙离子浓度(Ca(2+))。本体外研究的目的是探讨左旋布比卡因诱导的收缩是否与增加的 Ca(2+)敏感性有关，并鉴定参与对分离的大鼠主动脉平滑肌中左旋布比卡因反应的收缩的蛋白激酶。用乙酰氧甲酯的 fura-2 负载的主动脉条同时测量左旋布比卡因和氯化钾 (KCl) 对 Ca(2+)和张力的影响。在存在或不存在以下拮抗剂的情况下生成累积的左旋布比卡因浓度-反应曲线：GF 109203X；Y-27632；金雀异黄素；SP600125；PD 98059；和 SB 203580。使用 Western blot 在大鼠主动脉血管平滑肌细胞中检测左旋布比卡因诱导的蛋白激酶 C (PKC)、细胞外信号调节激酶 (ERK) 和 c-Jun NH(2)-末端激酶 (JNK) 磷酸化和 Rho-激酶 (ROCK-2) 膜易位。左旋布比卡因的 Ca(2+)-张力曲线的斜率高于 KCl。Y-27632、GF 109203X 和 SP600125 以浓度依赖性方式减弱左旋布比卡因诱导的收缩。金雀异黄素、PD 98059 和 SB 203580 减弱了左旋布比卡因诱导的收缩。GF 109203X 和 Y-27632 的预处理分别抑制了左旋布比卡因诱导的 PKC 磷酸化和 Rho-激酶 (ROCK-2) 膜易位。SP600125 或 PD 98059 的预处理分别减弱了左旋布比卡因诱导的 JNK 和 ERK 的磷酸化。这些结果表明，涉及肌丝 Ca(2+)敏感性增加的左旋布比卡因诱导的收缩涉及大鼠主动脉平滑肌中 Rho-激酶、PKC 和 JNK 介导的途径的主要激活。
