Distribution of pulmonary vascular resistance during lactic acid infusion in dogs.
Distribution of pulmonary vascular resistance during lactic acid infusion in dogs.
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狗输注乳酸期间肺血管阻力的分布。
DOI:
10.1152/jappl.1990.68.4.1328
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发表时间:
1990
期刊:
影响因子:
--
通讯作者:
Wood,LD
中科院分区:
文献类型:
--
作者:
Presberg,KW;Sznajder,JI;Melendres,J;Lewis,T;Abrahams,C;Wood,LD
We sought to determine the longitudinal distribution of pulmonary vascular resistance (PVR) in acute lactic acidosis utilizing pulmonary artery and vein balloon occlusion techniques (Holloway et al. J. Appl. Physiol. 54: 840-851, 1983). In anesthetized dogs, both a systemic vein (I-V) infusion and systemic artery (I-A) infusion of L-lactic acid were studied to control for potential effects of factors other than pH on PVR. During progressive I-A infusion (n = 9) to a pH of 6.94 +/- 0.06 there was no significant change in PVR or its distribution. In contrast, I-V infusion (n = 9) to a pH of 7.08 +/- 0.09 increased median PVR from 3.6 to 21.7 mmHg.1(-1).min (P less than 0.001), due to an increase in middle segment resistance (0.0-15.4 mmHg.1(-1).min, P less than 0.02). Examination by light and electron microscopy demonstrated pulmonary capillary obstruction with hemolyzed erythrocyte (RBC) membranes with I-V infusion, but representative I-A animals did not demonstrate these findings. Conceivably, the systemic vascular bed filtered the fragmented RBC membranes in the I-A model, but this microvascular obstruction with altered RBCs and RBC fragments caused the pulmonary hypertension observed in the I-V infusion. We conclude that lactic acidosis does not increase pulmonary vascular tone in dogs, a finding compatible with most previous studies in which observed increases in PVR may be attributed to other effects from I-V acid infusion on circulating blood elements.