Okudan N, Nurullahoğlu Atalik K E, Gökbel H, Canbilen A, Kara I
Department of Physiology, Meram Faculty of Medicine, Selçuk University, Konya, Turkey.
Yakugaku Zasshi. 2011;131(5):739-44. doi: 10.1248/yakushi.131.739.
The aim of this study was to ascertain the effects of α-lipoic acid (ALA) treatment on relaxant responses of acetylcholine (ACh) and isoprenaline (ISO) in aortic rings precontracted with serotonin (5-HT, 10(-6) M) obtained from streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in the rats by 50 mg/kg streptozotocin (STZ) via an intraperitoneal injection. Rat body and aorta weights were measured. The isometric tension to ACh (10(-9)-3×10(-6) M) and ISO (10(-9)-10(-4) M) of 5-HT-precontracted diabetic and non-diabetic rat (control), diabetic-ALA-treated, and ALA-treated aortas, in organ baths were recorded. Six weeks after STZ treatment blood glucose was elevated compared to control rats. In aortic rings from diabetic rats ACh and ISO-induced relaxations were impaired whereas endothelium-independent relaxation to sodium nitroprusside (SNP) was unaffected. ALA (100 mg/kg/day) treatment for 5 weeks enhanced ACh and ISO-induced relaxation in diabetic aortas. This recovering effect was via NO because prevented by incubating the vessels with N(G)-nitro-L-arginine methyl ester (L-NAME, a NOS inhibitor). It may be assumed that ALA treatment in vivo, can protect against impaired vascular responsiveness in STZ-induced diabetic rats.
本研究旨在确定α-硫辛酸（ALA）处理对从链脲佐菌素（STZ）诱导的糖尿病大鼠获得的、用5-羟色胺（5-HT，10⁻⁶ M）预收缩的主动脉环中乙酰胆碱（ACh）和异丙肾上腺素（ISO）舒张反应的影响。通过腹腔注射50 mg/kg链脲佐菌素（STZ）诱导大鼠患糖尿病。测量大鼠的体重和主动脉重量。记录在器官浴中5-HT预收缩的糖尿病和非糖尿病大鼠（对照）、糖尿病-ALA处理组和ALA处理组主动脉对ACh（10⁻⁹ - 3×10⁻⁶ M）和ISO（10⁻⁹ - 10⁻⁴ M）的等长张力。STZ处理六周后，与对照大鼠相比血糖升高。在糖尿病大鼠的主动脉环中，ACh和ISO诱导的舒张受损，而对硝普钠（SNP）的非内皮依赖性舒张未受影响。ALA（100 mg/kg/天）处理5周增强了糖尿病主动脉中ACh和ISO诱导的舒张。这种恢复作用是通过一氧化氮（NO）实现的，因为用N⁰-硝基-L-精氨酸甲酯（L-NAME，一种一氧化氮合酶抑制剂）孵育血管可阻止这种作用。可以推测，体内ALA处理可预防STZ诱导的糖尿病大鼠血管反应性受损。
