<原著>高酸素血症の局所心筋収縮力に及ぼす直接作用並びに体組織を介する間接作用に関する実験的研究 : 犬冠動脈局所灌流法による検索

概要

論文の詳細を見る
It has been shown that oxygen administration increases myocardial contractile force in an isolated heart muscle preparation while oxygen inhalation reduces the myocardial contractile force in vivo. The present study was designed to find what mechanism will be involved in making this discrepancy. In 34 mongrel dogs, the left anterior descending coronary artery was cannulated and perfused with their own blood from femoral artery (pO_2 : 90 ± 13 mmHg) at a constant perfusion rate. In this perfusion circuit, an artificial lung was used to saturate blood with oxygen (blood pO_2 : 463 ± 62 mmHg). It was made possible to perfuse either with blood directly from femoral artery (Air) or with blood from the artificial lung (O_2). A myocardial strain gauge arch was sutured on the myocardium where it was perfused with the blood from the cannulated artery. Myocardial contractile force was increased from 8.1 ± 5.6 (SD) to 8.8 ± 6.0 gm (an increase of 11.1 ± 20.1%, p<0.001), when perfusion was changed from Air to O_2 (Experiment I). The increase in myocardial contractile force was reduced (an increase of 8.0 ± 17.9%, p<0.05), when it was perfused with O_2 and perfusion rate was reduced by 20% (Experiment II). In the third experiment, the myocardium was kept perfused with O_2 and respiratory gas was changed from room air to oxygen. Myocardial contractile force was reduced by 4.1 ± 7.7% (p<0.02) in this experiment. The first experiment indicates that the direct effect of oxygen is to increase myocardial contractile force. The second experiment suggests that even though the regional myocardium becomes hyperoxic, if there is a concomitant decrease in coronary blood flow (as it is so in intact heart in vivo when breathing oxygen), the direct effect of oxygen on the contractile force of the myocardium will become less pronounced. The third experiment suggests that bodily hyperoxia causes a reduction in myocardial contractile force. The role of neurohumoral change elicited by hyperoxia on the whole body is suggested. It was concluded that the direct effect of oxygen on the myocardium (an enhancement of contractile force) was counteracted by (1) a reduction of coronary blood flow and (2) possibly by a neurohumoral effect.
近畿大学の論文
1977-09-25

<原著>高酸素血症の局所心筋収縮力に及ぼす直接作用並びに体組織を介する間接作用に関する実験的研究 : 犬冠動脈局所灌流法による検索

スポンサーリンク

概要

著者

関連論文

スポンサーリンク