Vasodilator effects of adenosine on retinal arterioles in streptozotocin-induced diabetic rats
Vasodilator effects of adenosine on retinal arterioles in streptozotocin-induced diabetic rats
复制标题
腺苷对链脲佐菌素诱导的糖尿病大鼠视网膜小动脉的血管扩张作用
DOI：
--
复制
发表时间：
2008
期刊：
影响因子：
--
通讯作者：
K. Ishii
中科院分区：
文献类型：
--
作者：
T. Nakazawa;A. Mori;M. Saito;K. Sakamoto;T. Nakahara;K. Ishii
腺苷是一种有效的视网膜血管扩张剂，并且被认为是代谢应激期间视网膜血流的主要调节剂，但关于糖尿病对腺苷在调节视网膜血流动力学中的作用的影响知之甚少。因此，我们研究了糖尿病如何影响腺苷诱导的视网膜小动脉血管舒张。用链脲佐菌素（80 mg/kg，腹膜内）处理雄性Wistar大鼠，并在6-8周后进行实验。用河豚毒素（50 μg/kg，静脉内[i. v.]）以消除任何神经活动并防止眼球运动，并持续输注甲氧胺以维持充分的体循环。用配备有特殊物镜透镜的数码相机拍摄眼底图像，并测量视网膜小动脉的直径。腺苷增加视网膜小动脉直径，降低体循环血压。一氧化氮合酶抑制剂NG-硝基-L-精氨酸甲酯（30 mg/kg，静脉注射）可显着减弱这些反应以及三磷酸腺苷依赖性K+（KATP）通道阻断剂格列本脲（20 mg/kg，i. v.）。糖尿病大鼠对腺苷的降压反应降低，而糖尿病并没有改变视网膜小动脉对腺苷的血管舒张作用。与此相反，糖尿病大鼠的降压反应和视网膜小动脉对乙酰胆碱的舒张反应均降低。NG-硝基-L-精氨酸甲酯可减弱糖尿病大鼠对腺苷和乙酰胆碱的视网膜血管舒张反应。在糖尿病和非糖尿病大鼠之间，对KATP通道开放剂吡那地尔的反应没有差异。这些结果表明，一氧化氮合酶的激活和KATP通道的开放有助于腺苷在大鼠体内的血管扩张作用。然而，糖尿病对视网膜循环中由这些机制介导的血管舒张没有显著影响。
Adenosine is a potent vasodilator of retinal blood vessels and is implicated to be a major regulator of retinal blood flow during metabolic stress, but little is known about the impact of diabetes on the role of adenosine in regulation of retinal hemodynamics. Therefore, we examined how diabetes affects adenosine-induced vasodilation of retinal arterioles. Male Wistar rats were treated with streptozotocin (80 mg/kg, intraperitoneally), and experiments were performed 6–8 weeks later. Rats were treated with tetrodotoxin (50 μg/kg, intravenously [i.v.]) to eliminate any nerve activity and prevent movement of the eye and infused with methoxamine continuously to maintain adequate systemic circulation. Fundus images were captured with a digital camera that was equipped with a special objective lens, and diameters of retinal arterioles were measured. Adenosine increased diameters of retinal arterioles and decreased systemic blood pressure. These responses were significantly attenuated by the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (30 mg/kg, i.v.) and the adenosine triphosphate-dependent K+ (KATP) channel blocker glibenclamide (20 mg/kg, i.v.). The depressor responses to adenosine were reduced in diabetic rats, whereas diabetes did not alter vasodilation of retinal arterioles to adenosine. In contrast, both depressor response and vasodilation of retinal arteriole to acetylcholine were reduced in diabetic rats. The retinal vasodilator responses to adenosine and acetylcholine observed in diabetic rats were diminished by NG-nitro-l-arginine methyl ester. There were no differences in the responses to pinacidil, a KATP channel opener, between the diabetic and nondiabetic rats. These results suggest that both the activation of nitric oxide synthase and opening of KATP channels contribute to the vasodilator effects of adenosine in rats in vivo. However, diabetes has no significant impact on the vasodilation mediated by these mechanisms in the retinal circulation.
登录
查看更多内容
影响因子：
4.4
作者：
G. Feke;S. Buzney;H. Ogasawara;N. Fujio;D. Goger;N. Spack;K. Gabbay
通讯作者：
G. Feke;S. Buzney;H. Ogasawara;N. Fujio;D. Goger;N. Spack;K. Gabbay
糖尿病视网膜血管自动调节。
影响因子：
13.7
作者：
Sinclair,SH;Grunwald,JE;Riva,CE;Braunstein,SN;Nichols,CW;Schwartz,SS
通讯作者：
Schwartz,SS
影响因子：
4.4
作者：
F. Robinson;C. Riva;J. Grunwald;B. Petrig;S. Sinclair
通讯作者：
F. Robinson;C. Riva;J. Grunwald;B. Petrig;S. Sinclair
影响因子：
3.5
作者：
T. Hein;L. Belardinelli;L. Kuo
通讯作者：
T. Hein;L. Belardinelli;L. Kuo
视网膜循环的自动调节响应灌注压的降低。
影响因子：
4.4
作者：
Riva,CE;Sinclair,SH;Grunwald,JE
通讯作者：
Grunwald,JE