肺血管床における液体交換の制御機構に関する研究

とくに肺血管内静水圧の影響について

抄録

In 5 anesthetized dogs, we measured lung lymph flow and lymph and plasma protein concentrations during a steady-state elevation of pulmonary microvascular pressure (Pmv). Lung water content was also measured at the end of experiments. Lung lymph flow increased and lymph protein concentration decreased approximately linearly whenever pulmonary vascular pressure rose. The increase in lymph protein flow was small, indicating no or little increase of protein permeability in pulmonary vascular endothelial membrane. The difference in plasma to lymph protein osmotic pressure increased as Pmv increased.
This induced a negative feedback inhibition of Pmv by plasma protein osmotic pressure and reduced transvascular fluid filtration in the lung. Lung water content, measured post-mortem, did not increase until a Pmv of more than 30cm H₂O, indicating a strong safety factor that protects the lung against fluid accumulation.