Nandhini A T Anitha, Thirunavukkarasu V, Anuradha C V
Departmernt of Biochemistry, Faculty of Science, Annamalai University, Annamalainagar 608-002, Tamil Nadu, India.
Can J Physiol Pharmacol. 2004 Jan;82(1):1-8. doi: 10.1139/y03-118.
The present work investigates the involvement of kinins in the effects of taurine in fructose-fed hypertensive rats. The effects of taurine on blood pressure, plasma glucose, insulin, and the insulin sensitivity index were determined. Angiotensin-converting enzyme (ACE) activity and nitrite content in plasma, plasma and tissue kallikrein activity, and taurine content were also investigated. The blood pressure changes in response to the coadministration of inhibitors of the synthesis of nitric oxide (NO), prostaglandins (PGs), or a kinin receptor blocker along with taurine was also evaluated. Fructose-fed rats had higher blood pressure and elevated plasma levels of glucose and insulin. Kallikrein activity, taurine, and nitrite contents were significantly lower in fructose-fed rats as compared with controls. The increases in systolic blood pressure, hyperglycemia, and hyperinsulinemia were controlled by taurine administration in fructose-fed rats. ACE activity was lower, while nitrite and taurine content and kallikrein activity were higher, in taurine-supplemented rats as compared with fructose-fed rats. A significant increase in blood pressure was observed in rats cotreated with the inhibitors Hoe 140 (a kinin receptor blocker), L-NAME (a NO synthase inhibitor), or indomethacin (a PG synthesis inhibitor) with taurine for 1 week as compared with taurine-treated fructose-fed rats. This suggests that the antihypertensive effect of taurine in fructose-fed rats was blocked by the inhibitors. Augmented kallikrein activity and, hence, increased kinin availability may be implicated in the effects of taurine in fructose-fed hypertensive rats.
本研究探讨了激肽在牛磺酸对果糖喂养的高血压大鼠的作用中的参与情况。测定了牛磺酸对血压、血浆葡萄糖、胰岛素和胰岛素敏感性指数的影响。还研究了血浆中的血管紧张素转换酶（ACE）活性和亚硝酸盐含量、血浆和组织激肽释放酶活性以及牛磺酸含量。同时评估了一氧化氮（NO）合成抑制剂、前列腺素（PGs）合成抑制剂或激肽受体阻滞剂与牛磺酸联合给药时的血压变化。果糖喂养的大鼠血压更高，血浆葡萄糖和胰岛素水平升高。与对照组相比，果糖喂养的大鼠激肽释放酶活性、牛磺酸和亚硝酸盐含量显著降低。在果糖喂养的大鼠中，牛磺酸给药可控制收缩压升高、高血糖和高胰岛素血症。与果糖喂养的大鼠相比，补充牛磺酸的大鼠ACE活性较低，而亚硝酸盐和牛磺酸含量以及激肽释放酶活性较高。与牛磺酸处理的果糖喂养大鼠相比，用抑制剂Hoe 140（激肽受体阻滞剂）、L-NAME（NO合酶抑制剂）或吲哚美辛（PG合成抑制剂）与牛磺酸共同处理1周的大鼠血压显著升高。这表明抑制剂阻断了牛磺酸对果糖喂养大鼠的降压作用。增强的激肽释放酶活性以及由此增加的激肽可用性可能与牛磺酸对果糖喂养的高血压大鼠的作用有关。
