The effect of losartan on the expression of Bax and Bcl-2 in renal tissue of SHR rats

CHEN Bao-lang; LI Rui

doi:10.3969/j.issn.1674-4055.2016.08.22

Abstract：Objective To investigate the effect of losartan on expression of Bax and Bcl-2 in renal tissue of spontaneously hypertensive (SHR)rats.Methods 30 male SHR rats and 15 male Wistar-Kyoto rats were selected. SHR rats were randomly divided into two groups: losartan group (n=15) and SHR positive control group (n=15), losartan group was administered losartan 30 mg/kg by gavage; SHR positive control group was administered 10mL/kg of 0.9% sodium chloride solution by gavage; as normal control group, Wistar-Kyoto rats were administered 10 mL/kg of 0.9% sodium chloride solution by gavage. All the rats were intragastrically administered every morning for 8 weeks. We compared systolic blood pressure of each group, expression of Bax and Bcl-2 in two groups were detected by immunohistochemical staining. The level of Bax mRNA and Bcl-2 mRNA were detected by fluorescence quantitative polymerase chain reaction (PCR).Results Tail artery systolic pressure of losartan group after administered 4 weeks and 8 weeks was significantly lower than before administration (P<0.05). Tail artery systolic pressure of losartan group after administered 4 weeks and 8 weeks was significantly lower than SHR positive control group (P<0.05). The average optical density of Bcl-2 in losartan group and normal control group were (0.19 ±0.01) and (0.20±0.02) respectively, which were significantly higher than SHR positive control group (P<0.05). The average optical density of Bax in losartan group and normal control group were(0.12±0.02) and (0.13±0.01) respectively, which were significantly lower than SHR positive control group (P<0.05). There was no significant difference in average optical density of Bax and Bcl-2 between the losartan group and the normal control group (P>0.05). As to relative expression of Bcl-2 mRNA and Bax mRNA, there was no significant difference between losartan group and the normal control group(P>0.05). The relative expression of Bcl-2 mRNA in SHR positive control group was significantly higher than losartan group and the normal control group; but the relative expression of Bax mRNA in SHR positive control group was significantly lower than Losartan group and the normal control group (P<0.05).Conclusion Losartan has a significant effect on the reduction of blood pressure in SHR rats, which can inhibit the expression of mRNA and protein of Bax, and promote the expression of mRNA and protein of Bcl-2.