Endothelium-derived hyperpolarizing factor does not contribute to the decrease in endothelium-dependent relaxation in the aorta of streptozotocin-induced diabetic rats.
1. We examined the contribution of endothelium-derived hyperpolarizing factor (EDHF) to the impairment of endothelium-dependent relaxation caused by acetylcholine (ACh) in the aorta of streptozotocin-induced diabetic rats, by using N omega-L-nitro-arginine methylester (L-NAME) and tetraethylammonium chloride (TEA) to inhibit nitric oxide (NO) and EDHF, respectively. 2. ACh-induced relaxation of the aorta decreased in diabetic rats. In contrast, sodium nitroprusside-induced relaxation was the same in diabetic rats and control rats. 3. Treatment with 5 x 10(-7) M L-NAME resulted in a right shift of the dose-response curves of ACh-induced relaxation in the aorta. The shift was greater in the control aorta. 4. Treatment with 5 x 10(-4) M TEA resulted in a similar right shift in both the control and diabetic aorta. 5. Therefore, while endothelium-derived NO appears to contribute to the impairment of ACh-induced endothelium-dependent relaxation in the aorta of diabetic rats, EDHF does not.
Endo
K
K
Biology Laboratory, Yamasa Corporation, Chiba, Japan.
Abiru
T
T
Machida
H
H
Kasuya
Y
Y
Kamata
K
K
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000503:physiopathology; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001685:Biological Factors / Q000502:physiology*; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D014664:Vasodilation
D001685:Biological Factors; D001786:Blood Glucose; D013757:Tetraethylammonium Compounds; C067410:endothelium-dependent hyperpolarization factor; D009569:Nitric Oxide; D013311:Streptozocin; D001120:Arginine; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester