RESUMEN
Objective To investigate the neuroprotective effect of soluble epoxide hydrolase (sEH) inhibitor 12-(3-adamantan-l-yl-ureido) dodecanoic acid (AUDA) on focal cerebral ischemia/reperfusion in rats and its mechanisms.Methods Sixty male Sprague-Dawley rats were randomly divided into sham operation and saline control groups,as well as low-dose (0.157 ml/kg),medium-dose (0.235 ml/kg) and high-dose (0.314 ml/kg) AUDA groups (n =12 in each group).Four rats in each group were selected for infarct volume,cell apoptosis and p-Akt immunohistochemistry detection.A model of middle cerebral artery ischemia/ reperfusion was induced by the suture method.The corresponding dose AUDA or equal volume of saline was injected intraperitoneally before reperfusion in each AUDA group and the saline control group.Neurological deficit scores were performed at 24 h of reperfusion.2,3,5 triphenyltetrazolium chloride (TTC) staining was used to detect infarct volume.TdT-mediated dUTP nick end labeling (TUNEL) was used to detect apoptotic cells of brain tissue in the periinfarction area.Immunohistochemical method was used to detect p-Akt expression of brain tissue in the peri-infarction area.Results TTC staining showed no infarction was observed in the sham operation group.The infarction volumes in the saline control group as well as the low-dose,medlum-dose and high-dose AUDA groups were 254.146 ± 25.481,212.679 ± 7.514,150.188 ± 33.997,and 99.563 ± 3.415 mm3,respectively.There were significant differences (F =39.637,P =0.000).The each dose AUDA group was significant less than the control group (all P=0.000).The medium-dose AUDA group was significantly less than the low-dose AUDA group (P=0.002),and the high-dose AUDA group was also significantly less than the low-dose AUDA group (P =0.000) and medium-dose AUDA group (P =0.006).TUNEL staining showed that a small number of apoptotic cells (6.400 ± 1.477/high-power field) were observed in the sham operation group.The numbers of apoptotic cells in the saline control group as well as in the low-dose,medium-dose and high-dose AUDA groups were 57.550 ± 13.067,47.030 ± 8.423,34.530 ± 4.393 and 26.400 ± 2.683/high power field,respectively.Each dose AUDA group was significantly less than the saline control group (all P ＜0.01).The medium-dose and high-dose AUDA groups were significantly less than the low-dose AUDA group (P ＜ 0.01),and the high-dose AUDA group was also significantly less than the medium-dose AUDA group (P ＜0.01).Immunohistochemistry showed that only a few p-Akt-positive cells (3.325 ± 1.438/high power field) were observed in the sham operation group.The numbers of p-Akt-positive cells in the saline control group as well as the low-dose,medium-dose and high-dose AUDA groups were 9.450 ±2.531,16.400 ± 3.865,22.875 ± 7.974,and 29.300 ± 3.203/high-power field,respectively.Each dose AUDA group was significantly more than the saline control group (all P ＜0.01).The medium-dose and high-dose AUDA groups were significantly more than the low-dose AUDA group (all P ＜0.01).The high-dose AUDA group was also significantly more than the medium-dose AUDA group (P ＜ 0.01).Conclusions The inhibition of sEH may decrease neuronal apoptosis and reduce infarct volume in the peri-infarction area by upregulating the PI3K/Akt pathway.It has a neuroprotective effect for focal cerebral ischemia/reperfusion in rats.