ANESTHETIC DEPRESSION OF THE MYOCARDIUM

在患者中观察到了低血压和心脏骤停 用麻醉剂氟烷、安氟醚和异氟烷麻醉。 这些挥发性麻醉剂(VA)今天在临床上被广泛使用。 初步证据表明，退伍军人管理局可能会降低可用性 心脏收缩所需的钙离子。该项目旨在 研究上述麻醉药对大鼠脑组织结构的影响 心肌细胞调节Ca~(2+)流量和控制钙离子强度 收缩。将被研究的元素是：肌膜(SL)， 肌肉细胞的外膜；肌浆网。 控制肌浆钙含量的膜性网络； 肌钙蛋白(Tn)，一种通过改变其对钙结合的反应的蛋白质。 塑造并启动收缩过程。实验也将是 在分离的乳头肌、心肌细胞和完整的动物身上进行 将发现的结果与分离的亚细胞结构相结合 生理上更复杂的系统。目前的证据表明 SR和SL受麻醉药的影响，可能是 收缩能力的改变。概述的研究与检查 氟烷、安氟醚和异氟烷与亚细胞的相互作用 结构来观察CA2反应的变化。结果将会是 量化每种麻醉剂对每种结构的相对影响 可能的行动机制将被假定。所获得的数据将 帮助制定药物干预措施，以防止麻醉- 在手术室引起心脏抑制。

Hypotension and cardiac arrest have been observed in patients anesthetized with the anesthetics halothane, enflurane, and isoflurane. These volatile anesthetics (VA) are in wide clinical use today. Preliminary evidence suggests that the VA might decrease the availability of Ca2+ required for cardiac contraction. This project is designed to study the effect of the above mentioned anesthetics on structures in the myocardial cell that regulate Ca2+ flux and control the intensity of contraction. The elements that will be studied are: the sarcolemma (SL), the outer membrane of the muscle cell; the sarcoplasmic reticulum (SR), a membranous network that controls the amount of myoplasmic Ca2+; and troponin (Tn), a protein that responds to Ca2+ binding by changing its shape and initiating the contractile process. Experiments will also be performed on isolated papillary muscles, myocytes and intact animals to integrate the results found with the isolated subcellular structures with systems of more physiological complexity. Present evidence suggest that the SR and SL are affected by anesthetics and may be the major sites of alteration of contractility. The studies outlined with examine the interaction of halothane, enflurane, and isoflurane with the subcellular structures to observe alteration in CA2+ response. The results will quantify the relative effect of each anesthetic on each structure and a possible mechanism of action will be postulated. The data obtained will help in formulating pharmacologic interventions to prevent anesthetic- induced cardiac depression in the operating room.