An approach to understand the pathogenesis of coronary artery spasm by molecular and cellular biology techniques

在这两年中，我们取得了以下成果：(1)研究了动脉粥样硬化（AS）和对照(C)兔主动脉收缩和磷酸肌苷（PI）转换。与C相比，5-HT刺激在AS中表现出增强的收缩和PI标记，尽管ne诱导的收缩和PI标记在两组中相同。这些结果表明，在动脉粥样硬化中存在5- ht介导的过度收缩和信号转导异常。(2)研究了内皮源性松弛因子（EDRF）对组胺（HA）诱导的兔胸主动脉血管收缩和PI转换的影响。HA表现为收缩和[^<32>P]Pi并入Pi。内皮和亚甲基蓝的去除增强了HA诱导的收缩和PI标记。这些结果表明，PI的周转和收缩响应HA是由负反馈EDRF调节的。(3)观察了天然低密度脂蛋白（LDL）和修饰低密度脂蛋白（LDL）对兔胸主动脉内皮依赖性松弛（EDR）的抑制作用。天然LDL对乙酰胆碱诱导的EDR无影响，PLA_2处理LDL和氧化LDL抑制EDR。此外，外源性给药合成LPC对EDR有明显的抑制作用。这些结果表明，LPC是抑制氧化LDL的主要物质。(4)测定兔主动脉溶血磷脂酶活性。该酶的激活不需要Ca^<2+>。胆固醇抑制溶血磷脂酶活性。这些结果可能暗示胆固醇抑制溶血磷脂酶活性的重要性，作为动脉粥样硬化血管中LPC积累增强的负责机制。(5)比较正常和动脉粥样硬化兔主动脉对人动脉利钠肽（hANP）的血管舒张反应。hanp诱导的AS松弛和环GMP形成明显减少。这些结果表明，汉肽通过膜结合鸟苷酸环化酶系统诱导的血管舒张反应在AS动脉中受损。少

We obtained the following results in these 2 years.(1) Contraction and Phosphoinositides(PI) turnover were studied in atherosclerotic(AS) and control(C) rabbit aortas. Stimulation with 5-HT in AS exhibited augmented contraction and PI labeling compared with C, although NE-induced contraction and PI labeling were identical in both groups. These results indicate that 5-HT-mediated hypercontraction and signal transduction abnormality were present in atherosclerotic arteries.(2) Effects of endothelium-derived relaxing factor(EDRF) on histamine(HA)-induced vasocsustriction and PI turnover were studied in rabbit thoracic aorta. HA exhibited contraction and [^<32>P]Pi incorporation into PI. Removal of the endothelium and methylene blue potentiate the contraction and PI labeling induced by HA. These results suggest that PI turnover and contraction in response to HA were regulated by the negative feedback EDRF.(3) The inhibitory effects of native low density lipoprotein(LDL) and modified LDL wi … More th copper oxidation and phospholipase A_2(PLA_2) on endothelium-dependent relaxation(EDR) were examined in rabbit thoracic aorta. Native LDL had no effects on ACh-induced EDR, whereas PLA_2 treated LDL and oxidized LDL inhibited EDR. Furthermore, exogeneous administration of synthetic LPC had a potent inhibitory action on EDR. These results indicate that LPC is the principal substance for the inhibitory effect of oxidized LDL.(4) Lysophospholipase activity was measured in rabbit aorta. The enzyme did not require Ca^<2+> for its activation. Cholesterol inhibited the lysophospholipase activity. These results may imply the importance of the lysophospholipase activity inhibition by cholesterol as the responsible mechanisms for the enhanced accumulation of LPC in atherosclerotic vessels.(5) The vasodilatory response to human arterial natriuretic peptide(hANP) were compared between normal and atherosclerotic(AS) rabbit aortas. The hANP-induced relaxation and cyclic GMP formation in AS were markedly reduced. These results suggest that hANP-induced vasodilating response through membrane-bound guanylate cyclase system is impaired in AS arteries. Less