Katz S D, Bleiberg B, Wexler J, Bhargava K, Steinberg J J, LeJemtel T H
Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461.
J Appl Physiol (1985). 1993 Nov;75(5):1974-9. doi: 10.1152/jappl.1993.75.5.1974.
Systemic and lower limb skeletal muscle lactate metabolism was studied in 10 men with congestive heart failure by use of a primed continuous intravenous infusion of L-(+)-[U-14C]lactate. Arterial and deep femoral venous blood samples were obtained at rest and during 30 min of submaximal exercise. Systemic lactate metabolic turnover rate (Rd) was determined using Steele's isotopic steady-state equation (Rd = isotopic infusion rate/arterial specific activity). Plasma lactate concentrations in the artery and deep femoral vein did not change significantly from resting values during exercise (1.11 +/- 0.13 vs. 1.26 +/- 0.12 and 1.27 +/- 0.12 vs. 1.30 +/- 0.12 mM, respectively), whereas Rd increased from 22.5 +/- 1.8 to 41.6 +/- 4.8 mumol.kg-1.min-1 (P < 0.005). Rd did not significantly correlate with arterial lactate concentration during rest or exercise. Because of simultaneous uptake and release of lactate in skeletal muscle, arterial and deep femoral venous lactate concentrations are not closely related to either systemic or lower limb skeletal muscle lactate metabolism in patients with congestive heart failure.
通过使用L-(+)-[U-¹⁴C]乳酸盐的首剂量连续静脉输注，对10名充血性心力衰竭男性患者的全身和下肢骨骼肌乳酸代谢进行了研究。在静息状态和次最大运动30分钟期间采集动脉血和股深静脉血样本。使用斯蒂尔同位素稳态方程（Rd = 同位素输注速率/动脉比活性）测定全身乳酸代谢转换率（Rd）。运动期间动脉和股深静脉中的血浆乳酸浓度与静息值相比无显著变化（分别为1.11±0.13对1.26±0.12以及1.27±0.12对1.30±0.12 mM），而Rd从22.5±1.8增加至41.6±4.8 μmol·kg⁻¹·min⁻¹（P < 0.005）。静息或运动期间，Rd与动脉乳酸浓度无显著相关性。由于骨骼肌中乳酸的同时摄取和释放，充血性心力衰竭患者的动脉和股深静脉乳酸浓度与全身或下肢骨骼肌乳酸代谢均无密切关系。
