Influence of blood and plasma flow rate on kinetics of serotonin uptake by lungs.
Influence of blood and plasma flow rate on kinetics of serotonin uptake by lungs.
复制标题
血液和血浆流速对肺部吸收血清素动力学的影响。
DOI：
10.1152/jappl.1982.53.3.677
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Linehan,JH
中科院分区：
文献类型：
--
作者：
Rickaby,DA;Dawson,CA;Linehan,JH
在肺动脉推注5-羟色胺和非渗透性指示剂后的5-羟色胺提取可以使用代表通过Michaelis-Menten动力学的5-羟色胺饱和摄取的模型来评估。通过使用该模型，可以通过时间-浓度数据的多元线性回归分析来确定Km、Vmax和灌注参数α。动力学和灌注参数，获得了使用数据，从孤立的狗肺叶，其中血浆流速改变血液或血浆灌注叶的泵流速或通过保持泵流速恒定，并删除血细胞。在研究中使用的流速范围内，计算的Vmax具有重现性且与流量无关。计算出的Km比Vmax对实验数据中的小变化更敏感，并且在流速大于每克肺组织正常心输出量的一半时与流量无关。灌注参数α在血浆灌注的叶中较低，反映了在不存在细胞的情况下更均匀的灌注。结果表明，这种方法将是有用的分离的变化，5-羟色胺摄取的内皮细胞的流量和灌注异质性的变化的影响的动力学。
Serotonin extraction following a bolus injection of serotonin and a nonpermeating indicator into the pulmonary artery can be evaluated using a model that represents the saturable uptake of serotonin by Michaelis-Menten kinetics. By use of this model Km, Vmax, and a perfusion parameter, alpha, can be determined by multiple linear regression analysis of the time-concentration data. Kinetic and perfusion parameters were obtained using data from isolated dog lung lobes in which plasma flow rate was changed by changing the pump flow rate in blood- or plasma-perfused lobes or by keeping the pump flow rate constant and removing the blood cells. The calculated Vmax was reproducible and flow independent over the range of flow rates used in the study. The calculated Km was more sensitive than Vmax to small variations in experimental data and was independent of flow at flow rates greater than about one-half the normal cardiac output per gram of lung tissue. The perfusion parameter alpha was lower in the plasma-perfused lobes, reflecting more homogeneous perfusion in the absence of cells. The results suggest that this approach will be useful for separating changes in the kinetics of serotonin uptake by endothelial cells from effects of changes in flow and perfusion heterogeneity.