关键词: Protectin DX, 肺叶切除术, 氧化应激反应, 炎症反应, HO-1, NF-κB

Abstract: Objective The role of Protectin DX ( PDX) in the regulation and protection of inflammatory mediators and oxidative factors related to lung injury after lobectomy in elderly rats was explored. Method Thirty healthy elderly male SD rats (10 months old) were randomly divided into the sham operation group, the surgery group and the PDX treatment group ( n = 10) . In the sham operation group and the operation group, 300 μL of physiological saline was injected intraperitoneally 1 hour after the modeling, and in the PDX treatment group, 300 μL of PDX (500 ng) was intraperitoneally injected 1 hour after the modeling. All rats were sacrificed by over-anaesthesia 24 h after modeling, and specimens were collected. The pathological changes of lung samples in each group were observed with HE staining, and the dry-wet mass ratio ( W / D) of lung samples in each group was evaluated. The protein concentration in the bronchoalveolar lavage fluid ( BALF ) was detected; the inflammation factors in the BALF was detected; the content of MDA, SOS, SOD and the expression of HO-1, nuclear factor ( NF) -κB protein in lung tissue were detected. Result The lung tissue structure of the sham operation group was clear, and no inflammatory cell infiltration was seen; the lung tissue structure of the elderly rats in the operation group was disordered, accompanied by a large number of inflammatory cell infiltration. Compared with the sham operation group, the lung injury score and lung tissue W / D of the elderly rats in the operation group were significantly increased ( P < 0. 01) . The protein concentration and the contents of IL-1β, IL-6 and TNF-α in alveolar lavage fluid were significantly increased ( P<0. 01) , and the levels of MDA, ROS and NF-κB protein in lung tissues were significantly increased, SOD activity and HO- 1 protein expression was significantly reduced ( P<0. 05) . Compared with the surgery group, the lung injury score and lung tissue W / D of aged rats in the PDX treatment group were significantly reduced ( P<0. 01) . The protein concentration and the contents of IL-1β, IL-6 and TNF-α in alveolar lavage fluid were significantly decreased ( P<0. 01) , the MDA, ROS content and NF-κB protein expression in lung tissue were significantly reduced, SOD activity and HO-1 Protein expression was significantly increased ( P < 0. 05) . Conclusion PDX could significantly reduce the lung injury after lobectomy in elderly rats. This effect may be related to the regulation of HO-1 and NF-κB protein expression in the lung tissues, thereby inhibiting the oxidative stress and inflammation in the lungs.

Key words: Protectin DX, Lobectomy, Oxidative stress response, Inflammatory response, HO-1, NF-κB