Protection Of Nimodipine Opposed The Arterial Blood Smooth Muscle Injury Induced By Hydrogen Peroxide

Objective:To observe the protection of Nimodipine against the oxidative stress injury induced by hydrogen peroxide(H₂O₂)and apoptosis on porcine basilar artery and human umbilical artery smooth muscle cells(HUASMCs).To provise new experimental evidence for clinical amplication of Nimodipine.Methods:(1)Porcine basilar artery rings without endothelium were prepared injured by H₂O₂ and then were divided into 6 groups:control group,H₂O₂-treated(2×10^-4mol·L^-1)group,Vitamin C(10^-4mol·L^-1) pretreatment group,Nimodipine at high,moderate and low dose(5×10^-6 mol·L^-1,5×10^-7mol·L^-1,5×10^-8mol·L^-1)pretreatment groups.We compared their basilar artery rings' changes of tension treated with chloratum kalium,phenylephrine and H₂O₂.Moreover,we observed the activity of superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-PX)and the contents of malondialdehyde(MDA)in vascular tissue.(2)The resistant effect of Nimodipine(10^-7—10^-10 mol·L^-1)and Vitamin C(10^-4mol·L^-1)against the apoptosis of HUASMCs induced by H₂O₂(10^-4mol·L^-1)was also studied by means of MTT chromatometry,flow cytometry,Hoechst staining and the expression of caspase-3.Results:(1)a.Compared with the control group,more significant contractile response to chloratum kalium,phenylephrine and H₂O₂ was observed in the vascular ring of the H₂O₂-treated group.And Vitamin C could not inhibit the contractile response to chloratum kalium, phenylephrine in H₂O₂-treated group.Nimodipine pretreatment at high, moderate and low dose inhibited the contractile response of the vascular ring to chloratum kalium,phenylephrine and H₂O₂ in dose dependent manner,b.Compared with the control group,the content of MDA in H₂O₂-treated group significantly increased,while the activities of SOD, CAT,GSH-PX were just at the opposite,the P values were all less than 0.05.Compared with the H₂O₂-treated group,the activity of SOD,CAT, GSH-PX and the content of MDA decreased in vascular tissue after treated with Nimodipine at high,moderate,low dose and Vitamin C, respectively.(2)In H₂O₂-treated group,the cell viability significantly decreased,while apoptosis and expression of caspase-3 protein increased. Fluorescein stain showed there were typical apoptotic bodies.Nimodipine could significant increase smooth muscle cell viability(P＜0.05),and Nimodipine at the concentration of 10^-9mol·L^-1had the strongest protective effect.Furthermore,cells showed low apoptosis rate,reduced apoptotic body in fluorescence staining and depressed expression of caspase-3 protein in Nimodipine at 10^-9mol·L^-1and Vitamin C groups(P＜0.05).Conclusions:Nimodipine is more efficient to inhibit the oxidative stress injury induced by H₂O₂ than Vitamin C.It can also inhibit HUASMCs apoptosis induced by H₂O₂.The mechanism is related to the low expression of caspase-3.