叶酸对去卵巢大鼠抗氧化酶、一氧化氮合酶和一氧化氮的影响

 目的: 观察叶酸对去卵巢大鼠抗氧化酶、一氧化氮合酶和一氧化氮的影响。方法: 40只3月龄健康雌性SD大鼠,随机分成5组:假手术组、去卵巢组、二乙基己烯雌酚(0.03 mg·kg^-1·d^-1)组、低剂量(5 mg·kg^-1·d^-1)叶酸组和高剂量(20 mg·kg^-1·d^-1)叶酸组。各组大鼠于术后1周开始灌胃给药,假手术组和去卵巢组给予蒸馏水,10周后,取L₅椎体和右股骨行骨密度(BMD)检测;测定血浆和骨匀浆总抗氧化能力(TAC)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)、一氧化氮合酶(NOS)和一氧化氮(NO)水平。结果: 与假手术组比较,去卵巢组大鼠L₅椎体和股骨BMD显著降低(P < 0.01),血浆GSH-Px、NO和骨匀浆TAC、GSH-Px、NOS及NO水平明显降低(P < 0.01),MDA浓度升高显著(P < 0.01);与去卵巢组大鼠比较,高剂量叶酸组大鼠L₅椎体和股骨BMD增加(P < 0.01),骨匀浆TAC、GSH-Px、NOS和NO水平升高(P < 0.01),MDA浓度降低(P < 0.01),血浆GSH-Px和NO水平升高。结论: 去卵巢大鼠体内抗氧化酶、NOS和NO水平降低,氧化应激参与了去卵巢大鼠骨质疏松的发生;高剂量叶酸能提升去卵巢大鼠腰椎和股骨BMD,提高其体内抗氧化酶、NOS和NO水平,改善氧化应激,这可能是高剂量叶酸防治去卵巢大鼠骨质疏松的机制之一。

Effects of folic acid on antioxidant enzyme,nitric oxide synthase and nitric oxide in ovariectomized rats

AIM: To observe the effects of folic acid (FA) on antioxidant enzyme, nitric oxide synthase (NOS) and nitric oxide (NO) in ovariectomized (OVX) rats.METHODS: Forty three-month-old female SD rats were randomly divided into 5 groups: sham group, OVX group, diethylstilbestrol group (0.03 mg·kg^-1·d^-1), low-dose FA group (5 mg·kg^-1·d^-1) and high-dose FA group (20 mg·kg^-1·d^-1). Gastric gavage started 1 week after operation and lasted for 10 weeks. The rats in sham group and OVX group were given distilled water instead of FA as controls. At the end of the 10th week, the L₅ vertebra and right femur were removed for determination of bone mineral density (BMD). The bone homogenates were made using the L₃ and L₄ vertebrae. The levels of the total antioxidant capacity (TAC), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), NOS and NO were detected in plasma and bone homogenates.RESULTS: Compared with sham group, the BMD levels in L₅ vertebra and right femur and the levels of GSH-Px and NO in the plasma were all decreased. The levels of TAC, GSH-Px, NOS and NO in the bone homogenates were also decreased, while the MDA concentration was increased in OVX group (all P < 0.01). Compared with OVX group, the levels of TAC, GSH-Px, NOS, NO and BMD of the L₅ vertebra and right femur were all increased, while the MDA concentration was decreased in high-dose FA group (all P < 0.01). CONCLUSION: In female SD rats, ovariectomy leads to a significant reduction of antioxidant enzyme, NOS and NO levels. Oxidative stress is possibly involved in the development of osteoporosis. Protection against osteoporosis by high-dose FA may be linked to improvement of antioxidant enzyme activity, the levels of NOS and NO as well as a reduction of oxidative stress in ovariectomized rats.