Résumé
Objective To investigate whether the excessive production of reactive oxygen species (ROS) in the mitochondria of the rostral ventrolateral medulla (RVLM) can inhibit the high salt-induced hypertension response.Methods A total off 32 male rats were divided into two groups:two groups were given normal salt diet (0.3％ NaCl) for 8 weeks (n=16) and high salt diet (8％ NaCl) for 8 weeks (n=16,induced hypertension model) respectively.The two groups were divided into four groups,two groups were given α-lipoic dissolving in 0.9％ normal saline (60 mg/kg),two groups were fed with saline for 9 weeks.There were ffour groups:the experimental group (n=8,the hypertension model sample fed α-lipoic acid),the model group (n=8,the hypertension model sample fed saline),the control group (n=8,normal salt diet sample fed α-lipoic acid) and the blank control group (n=8,normal salt diet sample ffed saline).Monitored the change of the arterial pressure and detected the expression off superoxide by immunofluorescence at the end of the experiment,measured the expression of NAD(P)H NOX2,NOX4 and Cu/Zn-SOD in RVLM by Western blot;determined the expression differences of oxidative stress related substances such as mitochondrial malondialdehyde(MDA)in RVLM by ELISA.Results The mean arterial pressure (MAP) in the experimental group was lower than that in the model group,the difference was statistically significant (P＜0.05);in the experimental group and the model group the intensities of fluorescent-labled dihydroethidium(DHE) were 60.2±3.1,99.1±3.8;the numbers of positive neurons in Cu/Zn-SOD were 20.8±1.1,6.9 ± 1.2;the numbers of NOX2 positive neurons were 12.3 ± 3.5,25.1 ±5.4;the numbers of NOX4 positive neurons were 10.1±2.2,13.3±4.1,the difference was statistically significant (P＜0.05).Western blot showed that the NOX2 levels of the experimental group and the model group were 78.9 ± 2.0,112.7 ± 3.8;the levels of NOX4 were 63.2± 2.1,99.4 ± 1.7.The levels of Cu/Zn-SOD in RVLM of the experimental group and the model group were 19.7 ±1.6,10.3± 1.2,the difference was statistically significant (P＜0.05);the levels of mitochondrial superoxide dismutase (SOD) were (33.1±3.8),(15.2±1.7)U/mg,the difference was statistically significant (P＜0.05).The levels of mitochondrial glutathione (GSH) in the experimental group and the model group were (5.2±0.9),(2.3±0.5)μmol/g;the levels of norepinephrine (NE) were (325.8 ± 7.3),(467.9 ± 6.1) pg/mL,the difference was statistically significant (P＜0.05).Conclusion α-lipoic acid could decrease the expression of NOX2,NOX4 and the bioenergy of mitochondria enzyme,and increase the intracellular antioxidant ability in the RVLM during the development of hypertension to inhibit the oxidative stress response in the development of hypertension.