Protective effect of testosterone on mitochondrial damage of vascular smooth muscle cells of castrate rats

ZHOU Wei; CHEN Ling; CHEN Man-hua

Abstract：Objective To investigate the protective effect of testosterone on the mitochondrial damage of vascular smooth muscle cells of castrated rats,and to explore its possible mechanisms. Methods A total of 30 male Sprague -Dawley(SD)rats were randomly divided into sham - operated group,castrated group(treated with normal saline),and castrated ﹢ testosterone group(treated with testosterone 5. 0mg/ kg daily). After treatment for 12 weeks,the rats were sac-rificed,and blood samples were drawn for measurement of plasma testosterone. The expression of Mitofusin 2(Mfn2)was detected by western blotting. The mitochondrial morphology and distribution was observed through laser confocal microsco-py. The mitochondrial membrane potential(ΔΨm)was detected by JC - 1 staining method. The total contents of ATP, superoxide dismutase(SOD),glutathione peroxidase(GSH - Px),and malondialdehyde(MDA)were determined by as-say kits. Results Compared with the sham group,the plasma testosterone level and Mfn2 protein expression in castrated group were significantly reduced(P < 0. 05);so were the ΔΨm,and the total contents of ATP,SOD,and GSH - Px;while the MDA was significantly increased(P < 0. 05). Mitochondrial fusion and morphology was dramatically altered in castrated group. Compared with the castrated group,significant increase in the plasma testosterone level,Mfn2 protein ex-pression,ΔΨm,and the total contents of ATP,SOD,and GSH - Px in castrated ﹢ testosterone group(P < 0. 05);so was the reduction in MDA level(P < 0. 05). No significant difference in mitochondrial morphology or distribution was ob-served between the sham and the castrated ﹢ testosterone groups. Conclusion Testosterone at physiological concentration plays a protective role in the mitochondrial damage of vascular smooth muscle cells of castrated rats,which may relate to up - regulation of mitofusin 2.