Duan J, Murohara T, Ikeda H, Sasaki K, Shintani S, Akita T, Shimada T, Imaizumi T
Cardiovascular Research Institute and Department of Internal Medicine III, Kurume University School of Medicine, Kurume, Japan.
Arterioscler Thromb Vasc Biol. 2000 Dec;20(12):2579-85. doi: 10.1161/01.atv.20.12.2579.
Hyperhomocysteinemia (HH) is an independent risk factor for atherosclerosis, including peripheral arterial occlusive disease (PAOD). Because angiogenesis and collateral vessel formation are important self-salvage mechanisms for ischemic PAOD, we examined whether HH modulates angiogenesis in vivo in a rat model of hindlimb ischemia. Rats were divided into 3 groups: the control group was given tap water, the HH group was given water containing L-methionine (1 g x kg(-1) x d(-1)), and the HH+L-arg group was given water containing methionine (1 g x kg(-1) x d(-1)) and l-arginine (2.25 vol%). At day 14 of the dietary modifications, the left femoral artery and vein were excised, and the extent of angiogenesis and collateral vessels in the ischemic limb were examined for 4 weeks. Plasma homocysteine levels significantly increased (P:<0.001), and plasma and tissue contents of nitrite+nitrate as well as tissue cGMP levels significantly decreased in the HH group compared with the control group (P:<0.01). Laser Doppler blood flowmetry (LDBF) revealed a significant decrease in the ischemic/normal limb LDBF ratio in the HH group at days 7, 14, 21, and 28 (P:<0.01 versus control). Angiography revealed a significant decrease in the angiographic score in the HH group at day 14 (P:<0.001 versus control). Immunohistochemistry of ischemic tissue sections showed a significant reduction in the capillary density in the HH group (P:<0. 001 versus control). Oral l-arginine supplementation in rats with HH (HH+L-arg) restored the decreased plasma and tissue nitrite+nitrate and cGMP contents (P:<0.05) as well as angiogenesis, as assessed by LDBF (P:<0.05 versus HH), angiographic score (P:<0.01 versus HH), and capillary density (P:<0.001 versus HH). In summary, HH impaired ischemia-induced angiogenesis and collateral vessel formation in a rat model of hindlimb ischemia in vivo. The mechanism of the HH-induced impairment of angiogenesis might be mediated in part by a reduced bioactivity of endogenous NO in the HH state.
高同型半胱氨酸血症（HH）是动脉粥样硬化的一个独立危险因素，包括外周动脉闭塞性疾病（PAOD）。由于血管生成和侧支血管形成是缺血性PAOD重要的自我挽救机制，我们研究了HH是否在大鼠后肢缺血模型中体内调节血管生成。大鼠分为3组：对照组给予自来水，HH组给予含L-蛋氨酸（1 g·kg⁻¹·d⁻¹）的水，HH+L-精氨酸组给予含蛋氨酸（1 g·kg⁻¹·d⁻¹）和L-精氨酸（2.25 vol%）的水。在饮食调整第14天，切除左股动脉和静脉，并在4周内检查缺血肢体的血管生成和侧支血管情况。与对照组相比，HH组血浆同型半胱氨酸水平显著升高（P<0.001），血浆和组织中亚硝酸盐+硝酸盐含量以及组织cGMP水平显著降低（P<0.01）。激光多普勒血流仪（LDBF）显示，HH组在第7、14、21和28天缺血/正常肢体LDBF比值显著降低（与对照组相比，P<0.01）。血管造影显示，HH组在第14天血管造影评分显著降低（与对照组相比，P<0.001）。缺血组织切片的免疫组织化学显示，HH组毛细血管密度显著降低（与对照组相比，P<0.001）。给HH大鼠口服补充L-精氨酸（HH+L-精氨酸）可恢复降低的血浆和组织中亚硝酸盐+硝酸盐及cGMP含量（P<0.05）以及血管生成，通过LDBF评估（与HH组相比，P<0.05）、血管造影评分（与HH组相比，P<0.01）和毛细血管密度（与HH组相比，P<0.001）。总之，HH在大鼠后肢缺血体内模型中损害了缺血诱导的血管生成和侧支血管形成。HH诱导的血管生成损害机制可能部分由HH状态下内源性NO生物活性降低介导。
