Effects of chronic diabetes on vascular responses of basilar artery and aorta from rabbits with alloxan-induced diabetes.
The influences of chronically diabetic states on contraction and relaxation responses of the isolated basilar artery and aorta to various vasoactive agents were examined in alloxan-induced diabetic rabbits with 2 years duration. There were no significant differences in the reactivities of basilar artery to norepinephrine (NE), 5-hydroxytryptamine (5-HT) and KCl between age-matched control and diabetic rabbits. Maximal contractions of aorta with endothelium in response to NE and 5-HT were significantly enhanced in case concentration-response curves for NE and 5-HT-induced contractions in the aorta without endothelium from diabetic rabbits were not different from those from age-matched control rabbits. Acetylcholine-induced relaxations in both the basilar artery and aorta from diabetic rabbits were significantly attenuated compared with those from age-matched control rabbits. However, no differences were observed in concentration-response curves for sodiumnitroprusside-induced relaxations in both the basilar artery and aorta between diabetic rabbits and age-matched control rabbits. These results indicate that chronic diabetes induces an specific enhancement in the contractile responses to NE and 5-HT in aorta and an attenuation in the endothelium-dependent relaxation in both the basilar artery and aorta. These results further demonstrated that the cerebral artery is resistant to diabetes of 2 years duration as compared with the peripheral artery.
Abiru
T
T
Biology Laboratory, Yamasa Shoyu Co., Ltd., Choshi, Japan.
Kamata
K
K
Kasuya
Y
Y
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000503:physiopathology; D001488:Basilar Artery / Q000187:drug effects* / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D012701:Serotonin / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
D009599:Nitroprusside; D012701:Serotonin; D011189:Potassium Chloride; D000109:Acetylcholine; D009638:Norepinephrine