Mechanisms of Anoxic Tolerance in Heart Muscle

心肌缺氧耐受机制

• 批准号: 9103158
• 负责人: Donald Jackson
• 金额: $ 27万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-10-01 至 1995-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9103158&HistoricalAwards=false
• 关键词: Mechanisms; Anoxic; Tolerance; Heart; Muscle

The physiological and biochemical adaptations of animals to environmental stresses will be studied. The major project concerns the tolerance of freshwater turtles to anoxia and acidosis similar to what they experience during their winter hibernation period. In addition, the respiratory and metabolic responses of bats during daily torpor, a normal occurrence in these animals, has recently been studied. Earlier work on whole animal responses, particularly metabolic and blood acid-base responses, found that long-term survival without oxygen is possible mainly due to a drastic reduction in energy metabolism, and to a lesser extent to effective buffering of accumulated acids by release of calcium carbonate from the shell. Recent research has been directed to the turtle heart in vitro, using perfused hearts either in a conventional tissue bath or in an NMR spectrometer. These studies have revealed that the isolated heart can maintain near normal levels of adenosine triphosphate (ATP) and mechanical function for many hours of anoxia, but when anoxia and acidosis are combined, the heart fails mechanically. One current objective is to learn whether this is really 'failure' or whether instead it is an adaptive arrest of function that enables survival under these conditions. Other current objectives involve defining cellular mechanisms of acid-base control, ion balance, and metabolic regulation that underlie the extraordinary behavior of these animals.

动物的生理和生化适应， 将研究环境压力。 重大项目 关注淡水龟对缺氧的耐受性， 与它们在冬天所经历的酸中毒相似 冬眠期 此外，呼吸和代谢 蝙蝠在日常休眠期间的反应， 这些动物，最近被研究。 早期关于整个动物反应的研究，特别是 代谢和血液酸碱反应，发现长期 在没有氧气的情况下生存是可能的，这主要是由于 减少能量代谢，并在较小程度上， 通过释放钙有效缓冲积累的酸 壳中的碳酸盐。 最近的研究已经指向 海龟的心脏在体外，使用灌注的心脏， 常规组织浴或核磁共振光谱仪中。 这些 研究表明，离体心脏可以维持近 三磷酸腺苷（ATP）和机械 功能缺氧多小时，但当缺氧和酸中毒 结合在一起心脏就会机械性衰竭 一个电流 目的是了解这是否真的是“失败”， 相反，它是一种功能自适应抑制， 在这种条件下生存。 其他当前目标 包括定义酸碱控制的细胞机制，离子 平衡和代谢调节， 这些动物的行为。