Kitoh Katsuya, Nakamura Hiroaki, Kitagawa Hitoshi, Unno Toshihiro, Komori Seiichi, Chiou Shin-Pin, Takashima Yasuhiro
Laboratory of Veterinary Parasitology, Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
J Vet Med Sci. 2017 Apr 8;79(4):740-744. doi: 10.1292/jvms.16-0590. Epub 2017 Mar 8.
Isolated rat thoracic aortic strips undergoing noradrenaline-induced contraction were treated with an adult heartworm (HW) crude extract and then examined for isometric changes in tension. HW extract caused relaxation of endothelium-intact strips, but not endothelium-denuded strips. This effect was inhibited by treatment with N-nitro-L-arginine methyl ester hydrochloride (L-NAME) and could be reversed by additional treatment with L-arginine. However, HW extract at a high concentration caused slight relaxation of endothelium-denuded strips, and relaxation persisted after L-NAME treatment in endothelium intact-strips. These data suggested that the relaxation induced by HW extract was mainly endothelium-dependent, nitric oxide-mediated, but in part, also endothelium-independent. In addition, a bioassay using isolated rat thoracic aortas may be a useful tool for investigating vasoactive substances in the HW extract.
对去甲肾上腺素诱导收缩的离体大鼠胸主动脉条用成年心丝虫（HW）粗提物进行处理，然后检测其等长张力变化。HW提取物可使内皮完整的血管条舒张，但对内皮剥脱的血管条无此作用。用盐酸N-硝基-L-精氨酸甲酯（L-NAME）处理可抑制该作用，而额外用L-精氨酸处理可使其逆转。然而，高浓度的HW提取物可使内皮剥脱的血管条轻微舒张，且在L-NAME处理后，内皮完整的血管条仍持续舒张。这些数据表明，HW提取物诱导的舒张主要依赖于内皮，由一氧化氮介导，但部分也是不依赖于内皮的。此外，使用离体大鼠胸主动脉进行生物测定可能是研究HW提取物中血管活性物质的有用工具。
