Sheehan F H, Goldstein R E, Bolli R, Epstein S E
Am Heart J. 1983 Jan;105(1):37-43. doi: 10.1016/0002-8703(83)90276-4.
The effect of nitroglycerin combined with methoxamine in reducing infarct weight was studied in conscious dogs. Ten minutes after permanent left anterior descending (LAD) coronary artery occlusion, 10 dogs received nitroglycerin (450 micrograms bolus IV, then 300 micrograms/min for 4 hours) and methoxamine as needed to maintain blood pressure and heart rate. No dogs in heart failure. Ten control dogs received saline solution. Dogs were sacrificed 3 days later. The region at risk of infarction was delineated by simultaneously perfusing the aortic root with Evans blue and the distal LAD artery with saline solution under equal pressures. Slices of stained hearts were incubated with tetrazolium to identify infarct. Total weight of left ventricle (LV), risk region, and infarct was measured. Nitroglycerin-treated dogs showed no difference from control dogs in infarct weight (26.2 +/- 5.9 gm +/- SE vs 27.7 +/- 5.6 gm), percent risk region/LV (36.0 +/- 1.4% vs 37.9 +/- 3.1%), or present infarct/LV (23.5 +/- 5.2% vs 24.8 +/- 4.9%). In a subgroup with risk region/LV less than or equal to 35%, nitroglycerin reduced infarct weight by 45% (8.8 +/- 8.5% vs 15.9 +/- 7.9%), percent infarct/LV by 49% (7.1 +/- 6.8% vs 13.8 +/- 6.6%), and percent infarct/risk region by 41% (23.0 +/- 22.0% vs 38.9 +/- 15.9%). Because of the small number of dogs in the study, differences were not significant. In dogs with risk region/LV greater than 35%, nitroglycerin had no effect. Thus, in dogs without overt heart failure, nitroglycerin may salvage ischemic tissue within small areas at risk of infarction, but the results are not definitive. However, our results clearly demonstrate that in the absence of failure, nitroglycerin does not reduce the size of large infarcts.
在清醒犬中研究了硝酸甘油联合甲氧明对减轻梗死重量的作用。在永久性结扎左冠状动脉前降支（LAD）10分钟后，10只犬接受硝酸甘油（静脉推注450微克，然后以300微克/分钟的速度持续4小时），并根据需要给予甲氧明以维持血压和心率。无犬发生心力衰竭。10只对照犬接受生理盐水。3天后处死犬。通过在等压条件下经主动脉根部灌注伊文思蓝和经LAD远端动脉灌注生理盐水来界定梗死危险区域。将染色后的心脏切片与四氮唑一起孵育以识别梗死灶。测量左心室（LV）、危险区域和梗死灶的总重量。硝酸甘油治疗组犬与对照组犬在梗死重量（26.2±5.9克±标准误对27.7±5.6克）、危险区域/LV百分比（36.0±1.4%对37.9±3.1%）或现存梗死灶/LV（23.5±5.2%对24.8±4.9%）方面无差异。在危险区域/LV小于或等于35%的亚组中，硝酸甘油使梗死重量减轻45%（8.8±8.5%对15.9±7.9%），梗死灶/LV百分比减轻49%（7.1±6.8%对13.8±6.6%），梗死灶/危险区域百分比减轻41%（23.0±22.0%对38.9±15.9%）。由于研究中的犬数量较少，差异无统计学意义。在危险区域/LV大于35%的犬中，硝酸甘油无作用。因此，在无明显心力衰竭的犬中，硝酸甘油可能挽救小面积梗死危险区域内的缺血组织，但结果不确切。然而，我们的结果清楚地表明，在无心力衰竭时，硝酸甘油不会减小大面积梗死灶的大小。
