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Effects of chronic alveolar hypoxia on pulmonary circulation

慢性肺泡缺氧对肺循环的影响

基本信息

批准号：
62480203
负责人：
HANDA Kenjiro
金额：
$ 1.41万
依托单位：
Shinshu University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

1) Cardiac morphological features under chronic hypoxia Three groups of male Wistar strain rats of newborn, 3 weeksage and 8 weeks-age were used to test the adaptative ability of age-dependent variability. Rats were raised to 2,400m altitude and had been kept for 7 to 9 weeks. In well-adapted rats under chronic mild hypoxia, cardiac hypertrophy should be restricted and haematocrit moderately elevated. Right ventricular wall should not react excessively. Mitochondria were small but cristal density and percentage area, estimated from electron micrographs, were found to be high. And to determine whether the heart of young, spontaneously hypertensive rat(SHR) could respond to chronically high altitude exposure with myocardial growth, SHR were raise to a high altitude research station at altitude of 2400m, where they were kept for 80 days. Chronic high altitude exposure caused increase of both right and left ventricular weights in both and controls.2) Physiological characteristics of Pika, as high altitude adapted animalsWe found pika, ochontona,living at Qinghai-Tibetan plateau are having completely adapted signs, especially like small degree of right ventricular hypertrophy, lower pulmonary artery pressure, and low haematocrit values. And these characteristics may have been genetically transmitted to following generation.3) Mechanism of hypoxic pulmonary vasoconstrictionWe investigated the effects of angiotensin converting enzyme inhibitor (captoril), calcium channel blocker (nifedipin), and thromboxane synthetase inhibitor on hypoxic pulmonary vasoconstriction in conscious sheep. Both captoril and nifesipin are potent vasodilating drug, and hypoxic vascular tone is not modulated by cyclooxygenase products.

1)慢性缺氧时心脏形态学的变化用新生、3周龄和8周龄三组Wistar雄性大鼠进行了年龄变异性的适应能力试验。将大鼠饲养至海拔2,400 m，并保持7 - 9周。在适应良好的大鼠慢性轻度缺氧，心肌肥大应限制和红细胞压积适度升高。右心室壁不应过度反应。线粒体小，但嵴密度和百分比面积，估计从电子显微镜照片，被发现是高的。为探讨自发性高血压大鼠（SHR）心脏对慢性高原暴露是否有心肌生长的反应，将SHR饲养于海拔2400 m的高原研究站，在那里饲养80天。2）高原适应动物鼠兔的生理特征我们发现生活在青藏高原的鼠兔（Ochontona）具有完全适应的体征，特别是轻度的右心室肥大、肺动脉压降低和红细胞压积降低。3）缺氧性肺血管收缩的机制我们观察了血管紧张素转换酶抑制剂（captoril）、钙通道阻滞剂（nifedipin）和血栓素合成酶抑制剂（thromboxane synthetase inhibitor）对清醒绵羊缺氧性肺血管收缩的影响。Captoril和nifesipin都是有效的血管舒张药物，缺氧血管张力不受环氧合酶产物的调节。