RESUMO
Objective To explore the curative effect of hyperbaric oxygen (HBO) on carbon monoxide (CO) poisoning of pregnant rats and its effect on learning and memory ability of the offspring rats. Methods A total of 120 pregnant SD rats (E3) were randomly divided into four groups: control, CO poisoning, CO poisoning+HBO and CO poisoning+normobaric oxygen (NBO) groups. The rats in the control group were not treated, while those in the other 3 groups were treated with acute CO poisoning. After successful modelling, the rats in the HBO group were treated with HBO (O2=99%, absolute pressure 250 kPa) till delivery, and the rats in the NBO group were treated with NBO (O2=99%, normal pressure) till delivery. The mortality rate of pregnant rats, the number of pups, the body mass of the pups and the mortality rate of pups were recorded, and the memory and learning ability of the offspring rats was assessed with Morris water maze. Results Compared with the CO poisoning group, HBO treatment could significantly reduce the mortality rate of pregnant rats and pups (0 vs 14.8% [4/27], 1.0% [3/292] vs 8.6% [18/209]; P<0.01, P<0.05), increase the number of pups and the body mass of pups (11.2±1.6 vs 9.1±2.1, [6.55±1.13] g vs [5.27±1.02] g; both P<0.05), and enhance the learning and memory ability of pups (escape avoidance latency was significantly shortened in Morris water maze, P<0.01). The above indicators were also improved after NBO treatment, but the effect was significantly lower than HBO treatment (P<0.05). Conclusion Both HBO and NBO can treat CO poisoning of pregnant rats, and can reduce the effects of CO poisoning on learning and memory ability of offspring rats, but the therapeutic effect of HBO treatment is better than NBO.
RESUMO
Objective To investigate the effect of hyperbaric oxygen preconditioning on exercise-induced fatigue in rats. Methods SD rats were subjected to loaded swimming after hyperbaric oxygen (250 kPa, φB[O2]≥99%) pretreatment, and rats exposed to normal pressured air were set as air control group. The time to exhaustion and levels of lactic acid (LA), malondialdehyde (MDA) and superoxide dismutase (SOD) in serum and skeletal muscle were observed to assess the effect of hyperbaric oxygen preconditioning on exercise-induced fatigue in rats. Results The time to exhaustion in loaded swimming of rats in hyperbaric oxygen pretreatment group was significantly prolonged compared with that in the air control group ([56. 13±16. 91] min vs[23. 13±9. 85] min, P<0. 01). After swimming for 20 min, the LA and MDA levels in the skeletal muscle and serum were significantly lower in the hyperbaric oxygen pretreatment group compared with air control group (P<0. 01), while the SOD levels in skeletal muscle and serum were significantly higher compared with air control group (P<0. 01). Conclusion Hyperbaric oxygen pretreatment can significantly delay the exercise-induced fatigue in rats.