Takeda M, Mori F, Yoshida A, Takamiya A, Nakagomi S, Sato E, Kiyama H
Department of Ophthalmology, Asahikawa Medical College, Midorigaoka-Higashi, Asahikawa, Japan.
Diabetologia. 2001 Aug;44(8):1043-50. doi: 10.1007/s001250100588.
AIMS/HYPOTHESIS: We investigated the association between vascular permeability and constitutive nitric oxide synthase in rats with diabetes for a short duration (2 weeks).
Retinal vascular permeability was evaluated in rats with diabetes induced by streptozotocin using vitreous fluorophotometry and a small animal adapter. We carried out in situ hybridization and semi-quantitative reverse transcription-polymerase chain reaction to study the expression of endogenous constitutive nitric oxide synthase mRNA in diabetic retinas. We also examined changes in the protein expression of constitutive nitric oxide synthase in diabetic retinas using immunohistochemistry and Western blotting.
Retinal vascular permeability was significantly higher in diabetic rats (median, 1.09 arbitrary unit) compared with control rats (median, 0.69 arbitrary unit) (p < 0.05). The expression of both neuronal nitric oxide synthase (NOS) and endothelial nitric oxide synthase mRNA was higher in diabetic retinas than in the retinas of control rats as determined by in situ hybridization and reverse transcription-polymerase chain reaction. Immunohistochemistry and Western blotting also showed that neuronal nitric oxide synthase increased in diabetic retinas. The immunohistochemistry of endothelial nitric oxide synthase indicated that non-vessel tissues increased in diabetic retinas while retinal vessels weakened. Western blotting showed that the amount of endothelial nitric oxide synthase increased.
CONCLUSION/INTERPRETATION: These results suggest that increases in both constitutive NOSs (nNOS and eNOS) could be associated with retinal vascular permeability and that NOS is associated with clinical vascular dysfunction in the early stages of diabetes.
目的/假设：我们研究了短期（2周）糖尿病大鼠血管通透性与组成型一氧化氮合酶之间的关联。
使用玻璃体荧光光度法和小动物适配器，对链脲佐菌素诱导的糖尿病大鼠的视网膜血管通透性进行评估。我们进行原位杂交和半定量逆转录-聚合酶链反应，以研究糖尿病视网膜中内源性组成型一氧化氮合酶mRNA的表达。我们还使用免疫组织化学和蛋白质印迹法检测糖尿病视网膜中组成型一氧化氮合酶蛋白表达的变化。
与对照大鼠（中位数为0.69任意单位）相比，糖尿病大鼠的视网膜血管通透性显著更高（中位数为1.09任意单位）（p < 0.05）。通过原位杂交和逆转录-聚合酶链反应确定，糖尿病视网膜中神经元型一氧化氮合酶（NOS）和内皮型一氧化氮合酶mRNA的表达均高于对照大鼠的视网膜。免疫组织化学和蛋白质印迹法也显示糖尿病视网膜中神经元型一氧化氮合酶增加。内皮型一氧化氮合酶的免疫组织化学表明，糖尿病视网膜中非血管组织增加而视网膜血管减弱。蛋白质印迹法显示内皮型一氧化氮合酶的量增加。
结论/解读：这些结果表明，组成型NOS（nNOS和eNOS）的增加可能与视网膜血管通透性有关，并且NOS与糖尿病早期的临床血管功能障碍有关。
