Muscle maximal O2 uptake at constant O2 delivery with and without CO in the blood.
Muscle maximal O2 uptake at constant O2 delivery with and without CO in the blood.
复制标题
血液中存在或不存在 CO 的情况下，恒定 O2 输送时肌肉的最大 O2 摄取量。
DOI：
10.1152/jappl.1990.69.3.830
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Haab,PE
中科院分区：
文献类型：
--
作者：
Hogan,MC;Bebout,DE;Gray,AT;Wagner,PD;West,JB;Haab,PE
在本研究中，我们观察了低氧时碳氧血红蛋白血症(HbCO)对肌肉最大摄氧量(VO2max)的影响。测定犬在体腓肠肌(n=12)最大工作状态(5 Hz等长收缩3min)的摄氧量(VO2)。肌肉以相同的血流量、动脉血氧分压(PaO2)和总血红蛋白浓度[(Hb)]泵入，血液中含有1%的HbCO(对照组)或30%的HbCO。在两种情况下，PaO2设置为30Torr，产生相同的动脉O2含量，肌肉血流量设置为120mL.100g-1.min-1，因此两种条件下的O2输送相同。为了最大限度地减少CO扩散到组织中，含HbCO的血液的灌流被限制在收缩时期。低氧血症时VO2max为8.8+/-0.6ml.min-1.100 g-1(n=12)，HbCO存在时VO2max下降26%至6.5+/-0.4ml.min-1.100 g-1(n=12，P<0.01)。两组患者的平均肌肉流出静脉血氧分压(PVO2)相同(16+/-1 Torr)。由于PaO2和PVO2在两种情况下是相同的，所以平均毛细血管PO2(平均O2驱动压的估计)在两种情况下可能没有太大差异，尽管HbCO使O2解离曲线左移。因此，HbCO很可能降低了血液到线粒体的O2扩散电导。
In the present study we investigated the effects of carboxyhemoglobinemia (HbCO) on muscle maximal O2 uptake (VO2max) during hypoxia. O2 uptake (VO2) was measured in isolated in situ canine gastrocnemius (n = 12) working maximally (isometric twitch contractions at 5 Hz for 3 min). The muscles were pump perfused at identical blood flow, arterial PO2 (PaO2) and total hemoglobin concentration [( Hb]) with blood containing either 1% (control) or 30% HbCO. In both conditions PaO2 was set at 30 Torr, which produced the same arterial O2 contents, and muscle blood flow was set at 120 ml.100 g-1.min-1, so that O2 delivery in both conditions was the same. To minimize CO diffusion into the tissues, perfusion with HbCO-containing blood was limited to the time of the contraction period. VO2max was 8.8 +/- 0.6 (SE) ml.min-1.100 g-1 (n = 12) with hypoxemia alone and was reduced by 26% to 6.5 +/- 0.4 ml.min-1.100 g-1 when HbCO was present (n = 12; P less than 0.01). In both cases, mean muscle effluent venous PO2 (PVO2) was the same (16 +/- 1 Torr). Because PaO2 and PVO2 were the same for both conditions, the mean capillary PO2 (estimate of mean O2 driving pressure) was probably not much different for the two conditions, even though the O2 dissociation curve was shifted to the left by HbCO. Consequently the blood-to-mitochondria O2 diffusive conductance was likely reduced by HbCO.(ABSTRACT TRUNCATED AT 250 WORDS)