THE INFLUENCES OF DEXMEDETOMIDINE ON INFLAMMATORY FACTORS AND TLR-4 EXPRESSION IN PLASMA AND PULMONARY TISSUES OF A LIPOPOLYSACCHARIDE-INDUCED SEPSIS RAT MODEL

Objective: To analyse the influences of dexmedetomidine on inflammatory factors and TLR-4 expression in plasma and pulmonary tissues of a lipopolysaccharide-induced sepsis rat model. Methods: 100 clean healthy male rats were selected, and a sepsis rat model was established. Rats were randomly divided into a sham operation group, model group, dexmedetomidine low-dose group (low-dose group), dexmedetomidine middle dose group (middle dose group), and dexmedetomidine high dose group (high dose group), each 20. The ratio of lung wet weight to lung dry weight of rats was compared between the groups. HE staining was used to observe changes in lung tissue. Plasma levels of tumour necrosis factor-alpha (TNF-alpha), interleakin-1 beta (IL-1 beta) and interleukin-6 (IL-6) were measured using an enzyme-linked immunosorbent assay. The expression of TLR-4 in lung tissue was determined using Western blotting. Results: Compared with the control group, the lung wet weight to dry weight ratio, plasma TNF-alpha, IL-1 beta and IL-6 levels and the expression of TLR-4 in lung tissue were significantly increased in the model group, low-dose group, middle-dose group and high-dose group (P<0.05). Compared with the model group, these levels were significantly lower in the middle dose group and the high dose group, with the lowest level in the high dose group (P<0.05). The lung tissue of control group rats was intact, with clear alveolar space and no oedema or inflammatory infiltration. In the model group, the alveolar space was widened and was accompanied by non-interstitial oedema, collapsed alveoli and inflammatory cell infiltration. The lung tissue of the rats in the low-dose group and the middle-dose group was alleviated compared with the model group; additionally, the inflammatory cell infiltration of the alveolar tissue in the high-dose group was significantly improved. Conclusion: The levels of plasma inflammatory factors and TLR4 in the lung tissue of septic rats were significantly increased. Dexmedetomidine significantly reduced plasma inflammatory factor levels and pulmonary tissue infiltration in septic rats.