Kohyama A, Inoue M, Doi T, Kimura H, Kitahata H, Saitoh T
Department of Anesthesiology, Tokushima University School of Medicine.
Masui. 1993 May;42(5):713-20.
We investigated the effects of blood glucose levels and myocardial glucose uptake on cardiac function during hypoxia in mongrel dogs (N = 50). During hypoxia (PaO2 = 20 mmHg) caused by inhalation of low concentration of oxygen for 2 hours, left ventricular (LV) function including LV pressure, maximum rate of rise of LV pressure, and cardiac index decreased significantly following initial enhancement. There were significant correlations between these hemodynamic parameters and blood glucose levels. The blood glucose levels correlated significantly with myocardial glucose uptake and blood lactic acid levels (r = 0.660: P = 0.000, r = 0.380: P = 0.000, respectively). Eight of nine dogs which died within 90 minutes during hypoxia showed low blood glucose levels and high lactic acid levels. During hypoxia, myocardial glucose uptake increased to more than five times of control value. On the other hand myocardial lactic acid uptake decreased and turned to production. At the same degree of blood lactic acid levels, LV function was maintained better with high blood glucose levels than with low levels. With low blood glucose levels, myocardial lactic acid uptake and production tended to cease. The pronounced change in LV function during hypoxia could be partially explained by decreased production of ATP due to decrease in myocardial glucose uptake and high lactic acid levels. It seems that high blood glucose levels are preferable to maintain cardiac performance under such a condition.
我们研究了杂种犬（N = 50）在缺氧期间血糖水平和心肌葡萄糖摄取对心脏功能的影响。在通过吸入低浓度氧气2小时造成缺氧（动脉血氧分压 = 20 mmHg）期间，左心室（LV）功能，包括左心室压力、左心室压力最大上升速率和心脏指数，在最初增强后显著下降。这些血流动力学参数与血糖水平之间存在显著相关性。血糖水平与心肌葡萄糖摄取和血乳酸水平显著相关（r分别为0.660：P = 0.000，r为0.380：P = 0.000）。在缺氧期间90分钟内死亡的9只犬中有8只血糖水平低且乳酸水平高。在缺氧期间，心肌葡萄糖摄取增加到对照值的五倍以上。另一方面，心肌乳酸摄取减少并转为生成。在相同程度的血乳酸水平下，高血糖水平比低血糖水平能更好地维持左心室功能。血糖水平低时，心肌乳酸摄取和生成趋于停止。缺氧期间左心室功能的显著变化部分可归因于心肌葡萄糖摄取减少和高乳酸水平导致的三磷酸腺苷生成减少。在这种情况下，高血糖水平似乎更有利于维持心脏功能。
