Sestoft L, Bartels P D, Folke M
Clin Physiol. 1982 Feb;2(1):51-8. doi: 10.1111/j.1475-097x.1982.tb00006.x.
The uptake of lactate, pyruvate and alanine in perfused rat liver was investigated under normal perfusion conditions (pH 7.4, PCO2 40 mmHg) and under conditions mimicking partially compensated metabolic acidosis (pH 6.9, PCO2 20 mmHg). At 1 mM lactate as well as 10 mM lactate in the medium a lowering of pH from 7.4 to 6.9 did not affect the lactate plus pyruvate uptake. A significant effect of the low pH was seen on pyruvate uptake which at 1 mM lactate was increased from 0.027 +/- 0.008(4) mumol/min per g liver at normal pH to 0.084 +/- 0.013(4) at low pH. At 10 mM lactate the liver produced pyruvate, but the production was significantly reduced by a lowering of the pH, being 0.45 +/- 0.13(8) mumol/min per g liver at pH 7.4 and 0.22 +/- 0.06(4) at pH 6.9. THe counterbalancing changes in lactate metabolism were too small to attain statistical significance. The stimulation of gluconeogenesis by an increase in FFA from 0 to 1 mM in the medium was unaffected by pH. Alanine uptake was decreased from 0.48 +/- 0.05(6) to 0.39 +/- 0.07(3) by lowering the pH from 7.4 to 6.9. We conclude that metabolic acidosis does not in itself inhibit the capacity of the perfused rat liver to remove lactate and pyruvate from the blood. If the same is true in man, no beneficial effect of bicarbonate treatment on lactate clearance in patients with lactic acidosis should be expected.
在正常灌注条件（pH 7.4，PCO₂ 40 mmHg）以及模拟部分代偿性代谢性酸中毒的条件（pH 6.9，PCO₂ 20 mmHg）下，研究了灌注大鼠肝脏对乳酸、丙酮酸和丙氨酸的摄取情况。当培养基中乳酸浓度为1 mM以及10 mM时，pH从7.4降至6.9并不影响乳酸加丙酮酸的摄取。低pH对丙酮酸摄取有显著影响，在1 mM乳酸浓度下，正常pH时丙酮酸摄取量为每克肝脏0.027±0.008(4) μmol/min，低pH时增加至0.084±0.013(4) μmol/min。在10 mM乳酸浓度下，肝脏产生丙酮酸，但pH降低会显著减少丙酮酸生成，pH 7.4时为每克肝脏0.45±0.13(8) μmol/min，pH 6.9时为0.22±0.06(4) μmol/min。乳酸代谢的平衡变化太小，无统计学意义。培养基中游离脂肪酸（FFA）从0增加到1 mM对糖异生的刺激不受pH影响。将pH从7.4降至6.9，丙氨酸摄取量从0.48±0.05(6)降至0.39±0.07(3)。我们得出结论，代谢性酸中毒本身并不抑制灌注大鼠肝脏从血液中清除乳酸和丙酮酸的能力。如果在人类中情况相同，那么不应期望碳酸氢盐治疗对乳酸酸中毒患者的乳酸清除有有益作用。
