Effects of chronic nicotine ingestion on pressor response to Nomega-Nitro-L-arginine methyl ester and ex vivo concentration and relaxation response of aorta to L-arginine.
Effects of nitric oxide synthase inhibition on blood vessels were studied in nicotine-treated rats. Male Sprague-Dawley rats drank a nicotine solution with a concentration of 25 or 50 microg/ml for 15 days. The blood pressure and heart rate of chloralose-anaesthetized rats and isolated aortic strip contractions were measured. NomegaNitro-L-arginine methyl ester (L-NAME)-induced hypertension was significantly reduced after chronic nicotine treatment. The Emax of contractions of isolated aortic strips to noradrenaline were dose-dependently enhanced by nicotine and the potentiation was abolished by L-arginine. The relaxation of aortic strips to acetylcholine was significantly decreased in nicotine-treated rats, whereas L-arginine, but not D-arginine, reversed this action. Neither nicotine nor L-NAME affected the heart rate. The results show that chronic nicotine treatment reduced the pressor response of L-NAME.
Hui
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S
Studies in Biomedical and Health Science, School of Professional and Continuing Education, University of Hong Kong, Pokfulam Road, Hong Kong, China.
Mei
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Q
Qiu
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B
D000109:Acetylcholine / Q000494:pharmacology; D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D001120:Arginine; D001794:Blood Pressure / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004326:Drinking; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology*; D009569:Nitric Oxide / Q000096:biosynthesis; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D004791:Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D009569:Nitric Oxide; D009538:Nicotine; D001120:Arginine; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine