Kaneko Daijiro, Komatsu Hiroyuki, Ohama Takashi, Sato Koichi
Department of Veterinary Pharmacology, Yamaguchi University, 1677–1 Yoshida, Yamaguchi 753–8515, Japan.
J Vet Med Sci. 2011 Aug;73(8):1001-5. doi: 10.1292/jvms.11-0068. Epub 2011 Apr 7.
The effect of trypsin on vascular tone and the cytosolic calcium concentration (Ca(2+)) of endothelial and smooth muscle cells were examined in the rat aorta. A calcium indicator, fura-PE3, was used to measure Ca(2+) simultaneously with vascular tone. In the endothelium-intact rat aorta, carbachol and trypsin increased Ca(2+) in a dose-dependent manner. In the endothelium-denuded rat aorta, carbachol did not change Ca(2+), but trypsin slightly increased it. Addition of trypsin to the norepinephrine-stimulated rat aorta relaxed the muscle with an additional increase in Ca(2+). Under calcium-free conditions, trypsin induced a transient increase in Ca(2+). Trypsin-induced endothelium-dependent relaxation was inhibited by preincubation with l-NMMA, an endothelial NO synthase inhibitor, U-73122, a phospholipase C inhibitor, cyclopiazonic acid, a sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase blocker, and lanthanum, a nonselective Ca(2+) channel blocker. However, indomethacin, a nonselective cyclooxygenase inhibitor, and SKF-96365, a store-operated Ca(2+)-channel blocker, had no effect on the trypsin-induced relaxation. These results suggest that trypsin increases Ca(2+) in the endothelial cells through SKF-96365-insensitive Ca(2+) channels and regulates the release of NO, which results in relaxation of the rat aorta.
在大鼠主动脉中研究了胰蛋白酶对血管张力以及内皮细胞和平滑肌细胞胞质钙浓度（Ca(2+)）的影响。使用钙指示剂fura-PE3同时测量Ca(2+)和血管张力。在内皮完整的大鼠主动脉中，卡巴胆碱和胰蛋白酶以剂量依赖方式增加Ca(2+)。在内皮剥脱的大鼠主动脉中，卡巴胆碱不改变Ca(2+)，但胰蛋白酶使其略有增加。向去甲肾上腺素刺激的大鼠主动脉中添加胰蛋白酶可使肌肉松弛，同时Ca(2+)进一步增加。在无钙条件下，胰蛋白酶诱导Ca(2+)短暂增加。胰蛋白酶诱导的内皮依赖性舒张被内皮型一氧化氮合酶抑制剂L-NMMA、磷脂酶C抑制剂U-73122、肌浆网/内质网Ca(2+)-ATP酶阻滞剂环匹阿尼酸以及非选择性Ca(2+)通道阻滞剂镧预孵育所抑制。然而，非选择性环氧化酶抑制剂吲哚美辛和储存性Ca(2+)通道阻滞剂SKF-96365对胰蛋白酶诱导的舒张无影响。这些结果表明，胰蛋白酶通过对SKF-96365不敏感的Ca(2+)通道增加内皮细胞中的Ca(2+)，并调节一氧化氮的释放，从而导致大鼠主动脉舒张。
