[Modulation of lymph microcirculation by sympathetic nerve during hemorrhagic shock of rat]

The present study was undertaken to examine the effect of sympathetic nerve on the changes of lymph microcirculation during hemorrhagic shock. After greater splanchnic nerve transection, changes of contractility of mesenteric micro-lymphatics (ML) in denervated rat were visualized and recorded by using a vital microscope with TV recorder during hemorrhagic shock and followed by refusion of withdrawn blood and infusion of saline. Results obtained showed that ML spontaneous contraction frequency, overall lymphatic contractile activity (Index II) and lymphatic dynamics (L. D-Index) decreased significantly after denervation. The ML spontaneous contractility decreased during hemorrhagic shock both in the denervated group and the intact group. During refusion of withdrawn blood and infusion of normal saline periods, the ML spontaneous contractility in the intact group was significantly higher than that of the pre-shock period, but in the denervated group it remained at a level, lower than that of the intact group (P < 0.01). During the post-infusion period the blood pressure was still much lower in the denervated than that of the intact group. The above results suggest that ML contractility shows decrease in hemorrhagic shock, while infusion of blood and normal saline may increase ML contractility and enhance blood pressure. The sympathetic nerve may play a modulation role to the recovery process of shock.