Brace R A
Department of Reproductive Medicine, University of California, San Diego, La Jolla 92093.
Am J Physiol. 1988 Jun;254(6 Pt 2):R1007-10. doi: 10.1152/ajpregu.1988.254.6.R1007.
The left thoracic lymph duct was catheterized at the base of the neck in the sheep fetus at 123-136 days of gestation, and the lymphatic catheter was connected to a jugular vein catheter so that the lymph could return to the fetus. Lymph flow was studied 5 days after catheter implantation in the unanesthetized fetus. Basal fetal thoracic duct lymph flow rate per unit body weight averaged three times adult sheep values. After an infusion of 20 ml/kg of warmed isotonic saline into a fetal vein over 5 min, lymph flow rate increased significantly to 161 +/- 15% of control, with a peak at 8 min after termination of the infusion, and flow declined thereafter. The increased lymph volume above baseline values over 30 min averaged 5.7% of the infused volume and is similar to the adult response. Plasma and lymph protein concentrations decreased as did the lymph-to-plasma protein concentration ratio. The latter is opposite to what occurs in the adult under the same conditions. Thus the present study shows that even though the fetus has a much higher basal thoracic duct lymph flow rate than the adult, the responsiveness of the fetal lymphatic system to intravascularly infused saline is similar to that of the adult. The decrease in the lymph-to-plasma protein concentration ratio suggests that there may be differences between fetal and adult vascular-interstitial-lymphatic protein kinetics.
在妊娠123 - 136天的绵羊胎儿颈部基部对左胸导管进行插管，并将淋巴管导管连接到颈静脉导管，以便淋巴液能够回流到胎儿体内。在未麻醉的胎儿中，于导管植入5天后研究淋巴液流动情况。胎儿单位体重的基础胸导管淋巴液流速平均为成年绵羊的三倍。在5分钟内将20毫升/千克温热的等渗盐水注入胎儿静脉后，淋巴液流速显著增加至对照值的161±15%，在输液结束后8分钟达到峰值，此后流速下降。30分钟内高于基线值的淋巴液增加量平均为输注量的5.7%，与成年羊的反应相似。血浆和淋巴液蛋白浓度降低，淋巴液与血浆蛋白浓度比值也降低。后者与成年羊在相同条件下的情况相反。因此，本研究表明，尽管胎儿的基础胸导管淋巴液流速比成年羊高得多，但胎儿淋巴系统对血管内输注盐水的反应性与成年羊相似。淋巴液与血浆蛋白浓度比值的降低表明胎儿和成年羊的血管 - 组织间隙 - 淋巴液蛋白动力学可能存在差异。
