title: Alpha lipoic acid treatment improved endothelium-dependent relaxation in diabetic rat aorta.
abstract: 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.
authors.affiliation: Department of Physiology, Meram Faculty of Medicine, Selçuk University, Konya, Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Okudan
authors.forename: K E
authors.initials: KE
authors.lastname: Nurullahoğlu Atalik
authors.forename: H
authors.initials: H
authors.lastname: Gökbel
authors.forename: A
authors.initials: A
authors.lastname: Canbilen
authors.forename: I
authors.initials: I
authors.lastname: Kara
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001011:Aorta / Q000187:drug effects*; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical; D008063:Thioctic Acid / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D008063:Thioctic Acid