The effects of isolated lipoproteins and triglyceride, combined oxidized low density lipoprotein (LDL) plus triglyceride, and combined oxidized LDL plus high density lipoprotein on the contractile and relaxation response of rabbit cavernous smooth muscle
The effects of isolated lipoproteins and triglyceride, combined oxidized low density lipoprotein (LDL) plus triglyceride, and combined oxidized LDL plus high density lipoprotein on the contractile and relaxation response of rabbit cavernous smooth muscle
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DOI：
10.1046/j.1365-2605.2000.00007.x
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发表时间：
2000-01-01
影响因子：
--
通讯作者：
Lee, MY
中科院分区：
文献类型：
--
作者：
Kim, SC;Seo, KK;Lee, MY
本研究旨在探讨分离脂蛋白、甘油三酯（TG）、氧化低密度脂蛋白（LDL）与甘油三酯（TG）、氧化低密度脂蛋白（LDL）与高密度脂蛋白（HDL）对兔海绵体平滑肌收缩和舒张反应的影响。在器官室中研究了新西兰白色兔的海绵体肌条，以测量等长张力。将条暴露于HDL，LDL，氧化LDL，TG，氧化LDL + TG和氧化LDL + HDL的组合30分钟。HDL和LDL都不影响海绵体肌肉的收缩和舒张反应。氧化LDL不影响去甲肾上腺素（NE）引起的收缩，但显著降低内皮依赖性激动剂乙酰胆碱（Ach）引起的舒张反应（p < 0.05）。非特异性NO合酶抑制剂（L-NAME）可完全抑制Ach引起的舒张反应，L-精氨酸可部分改善Ach引起的舒张反应。TG对Ach的舒张反应无明显影响，但降低了海绵体肌对NE的收缩反应。无论是合并氧化LDL加TG或氧化LDL加HDL对收缩和舒张反应有显着的协同或解毒作用。总之，氧化低密度脂蛋白可能有急性毒性作用的内皮依赖性，NO介导的舒张，但不是收缩，兔海绵体平滑肌。TG可降低海绵体肌的收缩力。当TG或HDL加入到氧化LDL中时，对收缩和舒张反应可能既没有协同作用也没有解毒作用。
The aim of this study was to investigate the effects of isolated lipoproteins and triglyceride (TG), and the effects of combined oxidized low density lipoprotein (LDL) plus TG and the combined oxidized LDL plus high density lipoprotein (HDL) on the contractility and relaxation response of rabbit cavernous smooth muscle. Cavernous muscle strips from New Zealand White rabbits were studied in organ chambers for isometric tension measurement. The strips were exposed to HDL, LDL, oxidized LDL, TG, combined oxidized LDL plus TG and combined oxidized LDL plus HDL for 30 min. Both HDL and LDL did not affect contraction and relaxation responses of the cavernous muscles. The oxidized LDL did not affect norepinephrine (NE)-induced contractility of the strips, but significantly (p < 0.05) decreased the relaxation response to endothelium-dependent agonist, acetylcholine (Ach). Non-specific NO synthase inhibitor (L-NAME) completely inhibited the relaxation response to Ach, and L-arginine partially improved the diminished relaxation. TG did not significantly change the relaxation responses to Ach, but decreased the contractility of cavernous muscle to NE. Neither the combined oxidized LDL plus TG nor oxidized LDL plus HDL had significant synergistic or detoxication effects on the contractility and relaxation responses. In conclusion, oxidized LDL may have acute toxic effects on the endothelium-dependent, NO-mediated relaxation, but not on the contractility, of rabbit cavernous smooth muscle. TG may decrease contractility of the cavernous muscle. There may be neither synergistic nor detoxication effects on the contractility and relaxation response when TG or HDL is added to the oxidized LDL.