Protective effects of dexmedetomidine on lung in rats with one-lung ventilation

Protective effect of dexmedetomidine (DEX) on the lungs of one-lung ventilation (OLV) rat model and its effect on inflammatory factors were investigated. Ninety-two rats were selected and divided into groups A, B, C and D (n=23) according to the principle of similar body weight. OLV rat model was established. Before modeling (15 min), rats in group C were injected with sodium chloride. Rats in group D were injected with DEX at a speed of 5 µg/kg/h. Group A rats were ventilated in both lungs for 2 h. Rats in groups B and C (0.9% sodium chloride injection + OLV) and in group D (DEX + OLV) were subjected to OLV for 2 h and bilateral ventilation for 10 min. Concentrations of interleukin (IL)-6, IL-10 and tumor necrosis factor-α (TNF-α) in lung tissue of rats were detected by ELISA. The malondialdehyde (MDA) concentration and superoxide dismutase (SOD) activity in rat lung tissue were detected by radioimmunoassay. Wet weight (W)/dry weight (D) of lung tissue was calculated and indexes of the four groups of rats were compared. Compared with group A, IL-6, TNF-α and MDA concentrations and W/D of lung tissue of rats in groups B, C and D were significantly increased (p<0.05); SOD activity and IL-10 concentration were significantly decreased (p<0.01). Compared with groups B and C, the concentrations of IL-6, TNF-α and W/D in rats of group D were significantly decreased (p<0.01), but IL-10 significantly increased (p<0.01). Compared with groups B and C, the MDA concentration in lung tissue of rats in group D was significantly decreased (p<0.01), but SOD activity significantly increased (p<0.01). DEX can inhibit the production of inflammatory factors in the development and progression of pulmonary inflammation. It can inhibit lipid peroxidation, relieve pulmonary edema, and reduce lung injury after OLV, sin order to protect the lung.