| Objective: To research the changes of the expression about insulin-like growth factor 1(IGF-1) in the brain tissue and the effect of hyperbaric oxygen on it through an acute organophosphate poisoning(AOPP) model of rats. Meantime, the mechanism of action is also explored in the hyperbaric oxygen treatment of brain injury caused by AOPP, which would provide theoretical basis in order to expand the application of hyperbaric oxygen.Methods: 60 healthy male SD rats were randomly divided into negative control group(n=6), poisoning group(n=18), routine group(n=18) and hyperbaric oxygen group(n=18). The later three groups were subdivided into 1,3,7h after the model was confirmed. The rats were injected subcutaneously with dichlorvos(4mg/kg) on the nape of neck for five times. Meanwhile, the rats were ensured continued convulsions for 3 hours. While the routine group was given instant injection with penehyclidine hydrochloride(0.12mg/kg) and pralidoxime chloride(30mg/kg), the hyperbaric oxygen group were received hyperbaric oxygen therapy immediately after conventional treatments. At the same time, the negative control group was injected the same volume of normal saline. The rats were sacrificed at the time points of 1,3,7 hours respectively by decapitated and the brains were removed, the cortex was fixed in 4% paraformaldehyde for paraffin embedding and pathological section, then their histopathological features were evaluated by Nissl’s staining and HE staining, the expression of IGF-1 protein were detected by immunohistochemical(IHC). The real time PCR was used to detect the expression of IGF-1 m RNA in hippocampus. The results were analized by statistic software SPSS.Results: Compared with the poisoning group, the histopathological damage of cerebral tissues in the hyperbaric oxygen group was lessend. The expression of IGF-1 content in routine group increased more significantly than those in the negative group and routine group(P<0.05). After the treatment of hyperbaric oxygen, the expression of IGF-1 was significantly higher than that of routine group at all time points after the hyperbaric oxygen treatment(P<0.05).Conclusion:The penehyclidine hydrochloride and pralidoxime chloride can be effective for brain injury caused by AOPP. Moreover, hyperbaric oxygen therapy is better than the former, and the earlier the better. Its underlying mechanism maybe attributed to the increased expression of IGF-1 in the brain. |
