维生素K2对老年去卵巢大鼠血管钙化的影响

Effect of Vitamin K2 on the Vascular Calcification of Old Ovariectomized Rats

目的在老年去卵巢大鼠模型上探讨维生素K2对血管钙化的影响。方法 36只10个月龄雌性SD大鼠,随机分为假手术组、去卵巢组、去卵巢+维生素K2组。去卵巢手术后3周,去卵巢+维生素K2组给予维生素K2灌胃30 mg/kg,每周5次,持续12周。各组大鼠在术前及药物干预后每3周留取血清及尿液,18周后处死大鼠,HE染色观察子宫、血管组织变化,酶联免疫吸附法检测血清和尿液基质Gla蛋白(MGP)含量及雌激素水平变化,荧光实时定量PCR检测胸主动脉MGP mRNA的表达,免疫组织化学法观察血管未羧化MGP(ucMGP)的表达,Von Kossa染色观察动脉钙化,原子分光光度计测定血管总钙含量。结果去卵巢后大鼠子宫和血管组织切片呈现明显不同,血中雌激素水平下降,表明去卵巢大鼠模型构建成功。去卵巢前各组大鼠血清及尿液中MGP含量无明显差异(P>0.05);去卵巢后,假手术组MGP含量无明显变化,去卵巢组MGP含量下降,去卵巢+维生素K2组MGP含量先下降后上升。去卵巢+维生素K2组血管中MGP mRNA表达量较假手术组高(P<0.01),较去卵巢组低(P<0.01)。血管ucMGP表达出现在血管钙化周围区域,去卵巢+维生素K2组未见明显ucMGP的表达。去卵巢+维生素K2组血管总钙含量明显低于去卵巢组(P<0.01),高于假手术组(P<0.05)。结论 MGP在绝经后血管钙化的发病中有重要作用,维生素K2可能通过调节MGP羧化及基因表达抑制血管钙化。

Aim To explore the effect of Vitamin K2 on vascular calcifiction in old ovariectomized rats model.Methods Thirty-six ten months female SD rats were allocated into three groups randomly： sham operation group,ovariectomized（OVX） group and OVX＋Vitamin K2（OVX＋VK2） group.Rats in OVX＋VK2 group were administered orally with Vitamin K2（30 mg（kg·d）,5 times a week） after three weeks of ovariectomy for 12 weeks.The urine and serum of all rats were kept every three weeks.All rats were sacrificed after 18 weeks,uterus and arteries were observed by histochemical method.The contents of MGP in serum and urine were determined by enzyme-linked immunosorbent assay（ELISA）.Relative quantification of MGP mRNA expression in arterial was detected by Fluorescent real-time quantitative reverse-transcription polymerase chain reaction.Expression of ucMGP was detected by immunochistochemistry.Aterial calcification was evaluated by Von Kossa staining.The content of arterial calcium was measured.Results After 18 weeks of ovariectomized,the pathological section of uterus and aortic had differernt variation in different groups.The content of estrogen in serum had no difference before ovariectomized.Before sacrifice,the content of estrogen of sham group had no change,the other groups reduced（P0.05）.The content of MGP in serum and urine had no difference before ovariectomized,the content of MGP in serum and urine decreased in OVX group,the content of MGP in serum and urine decreased and then increased in OVX＋VK2 group.Relative quantification of MGP mRNA expression of aterial in OVX＋VK2 group was significantly lower than sham group（P0.01）,and was higher than that in OVX group（P0.01）.The size of ucMGP localized in OVX＋VK2 group was less than that in OVX group.The contents of arterial calcium in OVX＋VK2 group were higher than that in sham group（P0.05） and lower than that in OVX group（P0.01）.Conclusions Vitamin K2 can improve vascular calcification of OVX rats possibly through the regulation of MGP carboxylation and gene expression.