Influence of dexamethasone on mesenteric lymph node of rats with severe acute pancreatitis

AIM： To study the influence and mechanisms of dexamethasone on mesenteric lymph node of rats with severe acute pancreatitis （SAP）. METHODS： The SAP rats were assigned to model, treated or sham-operated groups. The mortality, pathological changes of mesenteric lymph nodes, expression levels of NF-kB, P-selectin, Bax, Bcl-2 and caspase-3 protein and changes in apoptotic indexes in lymph nodes were observed at 3, 6 and 12 h after operation. The blood levels of endotoxin, superoxide dismutase （SOD）, malondialdehyde （MDA）, and endothelin-1 （ET-1） in blood were determined. RESULTS： SOD content, expression of Bax protein and apoptotic index were significantly higher in the treated group than in the model group at different time points （P 〈 0.05 or P 〈 0.01）. Other blood-detecting indexes and histopathological scores of mesenteric lymph nodes were lower in the treated than in the model group （P 〈 0.05, P 〈 0.01 or P 〈 0.01）. NF-kB protein expression was negative in all groups. Comparing P-selectin and caspase-3 expression levels among all three groups, there was no marked difference between the model and treated group. CONCLUSION： Dexamethasone can protect mesen-teric lymph nodes. The mechanism may be by reducing the content of inflammatory mediators in the blood and inducing lymphocyte apoptosis.