ABSTRACT
Objective To study the effect of APETx2 on the expression of ASIC3 APETx2 in a rat model of acute gastric mucosal lesion(AGML). Methods Twenty-four Wistar rats were randomly assigned to three groups in equal number : normal control group, water immersion restraint stress (WIRS) group, APETx2 treatment group. AGML was induced by WIRS for 6 hours, and APETx2 (25 μg/kg) was injected intraperitoneally before the onset of stress. Intragastric pH and gastric histopathological changes were measured and the expression of ASIC3 mRNA in DRG neurons projecting to rat stomach was examined by real-time PCR. Immunohistochemistry was performed to detect the localization of ASIC3. Results Compared with the normal control group, the WIRS group showed obvious gastric injury with lower values of intragastric pH and extensive expression of ASIC3 in the DRG neurons (P < 0.05). The treatment with APETx2 before the onset of WIRS significantly alleviated the gastric mucosal injury, decreased gastric acidity and reduced ASIC3 expression in DRG neurons (P < 0.05). Conclusions ASIC3 expression in DRG neurons projecting to rat stomach is strongly associated with gastric mucosal lesion and acidosis in the WIRS model. APETx2 can improve gastric acidosis and prevent the occurrence of these lesions.
ABSTRACT
Palm tocotrienol-rich fraction (TRF), an extract from palm oil containing both tocotrienol and tocopherol, is known for its antioxidant effect. The present study investigated the effect of palm TRF on the stomach using a water immersion restraint stress (WRS) model. Fortytwo male Sprague-Dawley rats were divided into three groups and were administered 60 mg/kg/d of palm TRF, α-tocopherol or vehicle only for 28 days. At the end of the treatment period, half of the rats from each group were subjected to WRS for 3.5 hours, after which the rats were sacrificed. The stomachs were then examined for lesions and measured for thiobarbituric acid reactive substance content and xanthine oxidase activity. Rats exposed to WRS showed gastric mucosal lesions. Pretreatments of the palm TRF and α-tocopherol reduced the occurrence of the lesions. WRS also increased gastric malondialdehyde content and xanthine oxidase activity significantly, but the increase in the oxidative stress parameters were significantly suppressed by both vitamin E pretreatments. However, the effects of palm TRF and α-tocopherol on the parameters measured were not different. In conclusion, palm TRF has the ability to protect against gastric mucosal injury, likely via its ability to inhibit oxidative stress.
ABSTRACT
Objective To definite the status of tone of autonomic nervous system during water immersion process by analyzing the nonlinear characteristic of ECG signals;To explore the relation of approximate entropy(ApEn),scaling exponent(?) changes and modulation function status of autonomic nervous system.Methods The ECG signals of rats during the process of restraint stress(RS),water-immersion restraint stress(WRS) and Vagotomy and Water-immersion restraint stress(vagotomy-WRS) were recorded.The ApEn and ? of RR intervals were calculated.Results After the stress,the differences of the value of ApEn and ? of RR intervals between RS and vagotomy-WRS groups and between different periods in vagotomy-WRS group were not significant.The value of ApEn increased in WRS group and decreased in RS group significantly.Compared with pre-stress,? showed decreased trend,all of the values smaller than 0.5 in WRS group and increased obviously,most values larger than 0.5 in RS group.Conclusion The increased ApEn and decreased ? indicates a higher intensity of parasympathetic activity.The parasympathetic activity is the predominant response of autonomic nervous system during water immersion process.