Effects of mesenteric lymph duct ligation on sepsis-induced lung and intestinal injuries in rats

Objective: To study the effect of mesenteric lymph duct ligation (MLDL) on sepsis-induced lung and intestinal injuries in rats. Methods: Sepsis was induced by cecal ligation and puncture (CLP) in male rats. The rats were randomly divided into sham control group in which rats received sham operation, sepsis group (CLP group) in which rats received saline after CLP operation, and CLP+MLDL group in which rats received mesenteric lymph duct ligation (MLDL) after CLP operation. The rats were sacrificed at 24 h after CLP modeling. Bronchoalveolar lavage fluid, arterial blood, and intestine and lung tissues were collected to determine organ injuries. Results: The lung tissue histopathology and blood gas analysis revealed that MLDL markedly alleviated the lung injury (ALI score: 6.14±0.51 vs. 8.12±0.63, P=0.029 9), improved oxygen partial pressure [(78.67±4.51)mmHg vs. (64.83±2.90)mmHg, P=0.0273], decreased lung W/D ratio (6.12±0.25 vs. 7.63±0.49, P=0.021 2), decreased BALF cytokines levels [TNF-α: (828.17±81.89)pg/mL vs. (1 118.17±79.22)pg/mL, P=0.029 1; IL-6: (39.33±5.50)ng/mL vs. (68.67±5.24)ng/mL, P=0.003 4], alveolar permeability [protein levels: 2.117±0.289 2 vs. 3.033±0.164 7, P=0.020 3, and cell levels: (30.00±3.587)×10⁶/L vs. (43.83±2.358)×10⁶/L, P=0.009 1]. However, according to the results of HE and biochemical detection, MLDL had no protective effect on sepsis-induced intestinal injury. Moreover, MLDL could significantly reduce the bacterial loads of the blood and lung, but do not change the bacterial level in the intestines. Conclusion: MLDL has a significant protective effect on sepsis-induced lung injury mainly by decreasing bacterial translocation, but had no effect on intestinal injury. This difference may be related to that MLDL inhibits the bacteria spreading from abdominal cavity to other organs in sepsis but it causes their accumulation in the intestines.