Müller M, Holmäng A, Andersson O K, Eichler H G, Lönnroth P
Lundberg Laboratory for Diabetes Research, Sahlgrenska University Hospital, Göteborg, Sweden.
Am J Physiol. 1996 Dec;271(6 Pt 1):E1003-7. doi: 10.1152/ajpendo.1996.271.6.E1003.
To study the relationship between blood flow rate and muscle metabolism, muscle microdialysis was performed in nine human subjects (5 females and 4 males) after an oral glucose load (75 g). Two microdialysis probes were inserted into the medial femoral muscle for estimation of glucose and lactate concentrations in the interstitial fluid, and the muscle blood flow was measured concomitantly with strain-gauge plethysmography. After subjects fasted overnight, their glucose concentration in arterial plasma and interstitial fluid was 4.6 +/- 0.13 vs. 3.8 +/- 0.23 mmol/l (P < 0.05), and the corresponding lactate concentrations were 0.60 +/- 0.07 vs. 0.83 +/- 0.07 mmol/l (P < 0.05). Muscle blood flow was 5.2 +/- 0.7 and 7.5 +/- 1.4 ml.100 g-1.min-1 (P < 0.05) at 0 and 90 min after oral glucose, respectively. The arterial-interstitial concentration differences of glucose increased after oral glucose [at 0 min 0.73 +/- 0.24 vs. 2.19 +/- 0.60 mmol/l at 90 min (P < 0.001)]. The corresponding values for lactate were -0.23 +/- 0.10 at 0 min vs.-0.26 +/- 0.18 mmol/l at 90 min (not significant). The data show that 1) the capillary wall is partly rate limiting for glucose uptake, and 2) after oral glucose, the glucose concentration gradient over the capillary wall increases despite a limited increase in blood flow rate, which then mediates approximately 10-20% of total enhancement of glucose uptake in muscle.
为研究血流速率与肌肉代谢之间的关系，对9名人类受试者（5名女性和4名男性）口服葡萄糖负荷（75克）后进行了肌肉微透析。将两根微透析探针插入股内侧肌，以估计组织间液中的葡萄糖和乳酸浓度，并同时用应变片体积描记法测量肌肉血流量。受试者过夜禁食后，其动脉血浆和组织间液中的葡萄糖浓度分别为4.6±0.13与3.8±0.23毫摩尔/升（P<0.05），相应的乳酸浓度分别为0.60±0.07与0.83±0.07毫摩尔/升（P<0.05）。口服葡萄糖后0分钟和90分钟时，肌肉血流量分别为5.2±0.7和7.5±1.4毫升·100克⁻¹·分钟⁻¹（P<0.05）。口服葡萄糖后，葡萄糖的动脉-组织间浓度差增大[0分钟时为0.73±0.24与90分钟时的2.19±0.60毫摩尔/升（P<0.001）]。乳酸的相应值在0分钟时为-0.23±0.10，在90分钟时为-0.26±0.18毫摩尔/升（无显著性差异）。数据表明：1）毛细血管壁对葡萄糖摄取有一定的速率限制作用；2）口服葡萄糖后，尽管血流速率增加有限，但毛细血管壁上的葡萄糖浓度梯度仍会增大，这一过程介导了肌肉中葡萄糖摄取总量增加的约10-20%。
