Protective effects of hydrogen on monoarthritis rats / 第二军医大学学报

ABSTRACT

Objective: To explore the protective effect of hydrogen (H2) inhalation through respiratory tract on monoarthritis (MA) rats. Methods: Forty male SD rats were randomly divided into 5 groups MA group, MA+H2 0-14 d group, MA+H2 0-3 d group, MA+H2 4-14 d group, and sham+H2 0-14 d group (n = 8). Complete Freund's adjuvant (CFA) was injected into the left ankle joint of rats to construct MA model. The rats in the MA group did not inhale H2, and the rats in other four groups inhaled 65% H2 1.5 h per day on the day of modeling and 1-14 days after modeling, 1.5 h per day on the day of modeling and 1-3 days after modeling, 1.5 h per day on the 4th-14th day after modeling, and 1.5 h per day on the day of sham operation and 1-14 days after modeling, respectively. Paw withdrawal threshold (PWT) was detected by von Frey method 0, 1, 3, 5, 7, 10, and 14 d after modeling. Another 15 rats were randomly divided into 5 groups and there were 3 rats in each group. Lumbar enlargement tissues were taken from the spinal cord of the inflammatory side on the 10th day after modeling or sham operation. The contents of superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were detected. Results: In the MA group, the posterior paw PWT of the inflammatory side was lower than that of the healthy side on the first day after modeling, reached the lowest on the 3th day and remained stable until the 14th day (P0.05). The levels of SOD and CAT in the spinal cord of the inflammatory side in the MA+H2 0-14 d group were higher than those in the MA group (all P0.05). Conclusion: Inhalation of 65% H2 via the respiratory tract at the initial stage of MA rat modeling can alleviate mechanical hyperalgesia and oxidative stress. Pre-administration of H2 can inhibit the formation of mechanical hyperalgesia in MA.