Effects of hydrogen saturated saline on the lung after paraquat poisoning

Objective To investigate protective effects of the hydrogen saturated saline on acute lung injury and pulmonary fibrosis in rats with paraquat (PQ) poisoning. Method Forty-eight Sprague-Dawley rats were randomly divided into 3 groups, namely control group, PQ poisoning group and intervention group (n = 16 rats in each group) . Animals in PQ poisoning group and intervention group were fed with PQ in dosage of 50 mg / kg. Rats of control group were fed equivalent amount of distilled water instead. One hour after administration of PQ, rats of intervention group were treated with 5 ml / kg hydrogen saturated saline injected intra-peritoneally twice a day until the rats were sacrificed. The rats of poisoning group and control group were treated with intra-peritoneal injection of equivalent amount of normal saline. Arterial partial pressure of oxygen ( PaO2 ), 8-hydroxy-2' -desoxyguanosine (8-OHDG) and transforming growth factor β1 (TGF-β1) of lung tissue were measured on the 3rd and 21st day after PQ administration. Quantitative data was expressed as mean ±standard deviation (x-±s) . SPSS version 12. 0 package was applied for variance analysis and SNK-q test, and statistical differences were considered significant when P ＜ 0. 05. Results ① PaO2 decreased significantly in poisoning group (9. 34 ± 0. 47 kPa) and intervention group (10. 30±0.62 kPa) compared with control group (11.87 +/- 0.42 kPa) on the 3d (P ＜0.01), and as intervention group was compared with poisoning group, there was a significant difference ( P ＜ 0. 05 ) . On the 21st day, PaO2 was still lower in poisoning group (8. 36 ±0. 51 kPa) and intervention group ( 10. 14 ±0. 27 kPa) than that in control group ( 11.87 +0. 24 kPa) (P ＜0. 01 and P ＜0. 05, respectively), and as intervention group was compared with poisoning group, there was a significant difference ( P ＜ 0. 01 ) . ②The levels of 8-OHDG in lung tissue increased significantly in poisoning group (23.58±7. 18 ng/ml ) and intervention group (9. 49± 2. 45 ng/ml) on the 3rd day after PQ administration compared with control group (7.71 + 1.96 ng/ml) (P＜0. 01 and P＜0. 05, respectively), and as intervention group was compared with poisoning group there was a significant difference ( p ＜0. 01 ) . There were no significant differences in 8-OHDG level found among the groups on the 21st day after PQ administration (P ＞ 0. 05 ) . ③ The level of TGF-β1 (measured by mean optic density, MOD) in lung tissue of rats in poisoning group ( 10. 11±2.49 MOD) and intervention group (8. 14 + 1.58 MOD) exhibited in higher levels than control group (5.93 + 1. 98 MOD) on the 3rd and (5.97 + 2. 35 MOD) on the 21st day after PQ administration (P ＜0. 01 and P ＜0. 05, respectively), and however, a lower level of TGF-β1 was observed in intervention group on 3d and 21d compared with poisoning group (P ＜0. 05 and P ＜0. 01, respectively) . Conclusions Hydrogen saturated saline can alleviate oxidative stress, mitigate oxidative damage and inhibit pulmonary fibrosis of lung induced by PQ intoxication. Key words: Paraquat;  Oxidative stress;  Lung;  Hydrogen saturated saline;  8-hydroxy-2'-desoxyguanosine;  Transforming growth factor β1;  Rats