Baldwin A L, Ferrer P, Rozum J S, Gore R W
Department of Physiology, College of Medicine, University of Arizona, Tucson.
Lymphology. 1993 Mar;26(1):4-18.
To determine the relative importance of the lymphatic system and transcapillary reabsorption in maintaining water distribution between blood and lymph in Rana pipiens, the hematocrit (HCT) was measured (12 frogs) when each frog was: 1) under tricaine methanesulfonate (MS222) anesthesia, which inactivates the lymph hearts, 2) conscious at rest (control), and 3) conscious after activity. Arterial pressure (AP), lymph-heart rate (LHR), and plasma and lymph protein concentrations and colloid osmotic pressures (COP) were also measured. The average HCT during control state was 26.0 +/- 5.2% (SD), AP was 21.9 +/- 5.2 mmHg, and LHR was 86 +/- 13 bpm. MS222 increased HCT (42.6 +/- 7.9%), and did not affect AP. Experiments, in which plasma volumes were determined by intra-arterial injection of Evans blue-labeled albumin (EB-BSA) (16 frogs), showed that the increased HCT reflected a reduced plasma volume. Activity did not affect HCT, but increased AP (33.1 +/- 6.4 mmHg, p < 0.01), and LHR (115 +/- 26 bpm, p < 0.01). Thus lymph hearts are largely responsible for maintaining blood volume, and changes in transcapillary filtration rate are rapidly mirrored by changes in lymph heart function. Plasma and lymph COP values after MS222 or activity were not significantly different from control. This observation is consistent with the protein and fluid fluxes resulting from Starling forces if an average reflection coefficient to protein, sigma, of 0.5 is assumed, which is consistent with our EB-BSA data.
为了确定淋巴系统和毛细血管重吸收在维持牛蛙血液与淋巴之间水分分布中的相对重要性，对12只牛蛙在以下三种状态下测量了血细胞比容（HCT）：1）处于三卡因甲磺酸盐（MS222）麻醉状态，此时淋巴心失活；2）静息清醒状态（对照）；3）活动后清醒状态。还测量了动脉压（AP）、淋巴心搏率（LHR）以及血浆和淋巴中的蛋白质浓度与胶体渗透压（COP）。对照状态下的平均HCT为26.0±5.2%（标准差），AP为21.9±5.2 mmHg，LHR为86±13次/分钟。MS222使HCT升高（42.6±7.9%），但不影响AP。通过动脉内注射伊文思蓝标记白蛋白（EB - BSA）测定血浆容量的实验（16只牛蛙）表明，HCT升高反映血浆容量减少。活动不影响HCT，但使AP升高（33.1±6.4 mmHg，p<0.01），LHR升高（115±26次/分钟，p<0.01）。因此，淋巴心在很大程度上负责维持血容量，毛细血管滤过率的变化会迅速反映在淋巴心功能的变化上。MS222或活动后血浆和淋巴的COP值与对照相比无显著差异。如果假设蛋白质的平均反射系数σ为0.5，这一观察结果与由斯塔林力导致的蛋白质和液体通量一致，这与我们的EB - BSA数据相符。
