虚血心筋ならびに骨格筋の交感神経機能の応答

抄録

To examine the effects of ischemia on cardiac and skeletal muscle sympathetic nerve activity, we used microdialysis technique on the hearts and skeletal muscle of anesthetized rabbits and measured dialysate norepinephrine (NE) and lactate (Lac) during ischemic skeletal muscle and myocardium. We applied microdialysis technique to the left ventricular myocardium and acute myocardial ischemia was induced by a 60-min occlusion of coronary artery. The dialysate NE and Lac levels were served as indices of NE release and myocardial ischemia. In separate rabbit, we applied microdialysis to adductor muscle and acute muscle ischemia was induced by 60-min occlusion of iliac artery. The basal myocardial dialysate NE and Lac levels were 48±6, 0.52±0.08 pg/ml. During ischemia the increase in myocardial dialysate NE(1062±252 at 0-15, 21099±3049 at 15-30, 36566±4466 at 30-45, 33058±3717 pg/ml at 45-60min) accompanied with the increase in dialysate Lac (1.87±0.36, 2.75±0.42, 2.34±0.26, 2.03±031 pg/ml). On the other hand, occlusion of iliac artery increased in skeletal muscle dialysate Lac(0.51±0.03 at basal, 0.89±0.09 at 0-15, 1.00±0.02 at 15-30, 1.21±0.09 at 30-45, 1.39±0.06 pg/ml at 45-60min) but decreased in skeletal muscle dialysate NE (19.3±2.2 at basal, 16.1±4.5, 9.4±3.4, 3.2±1.3, 2.3±0.4 pg/ml). Both occlusion of coronary and iliac artery induced increases in dialysate Lac in myocardium and skeletal muscle. However, ischemia induced differential NE responses in the myocardium and skeletal muscle. [Jpn J Physiol 54 Suppl:S202 (2004)]