Changes of endothelial functions in the coronary artery after chronic nitroarginine feeding.
1. The effects of chronic NG-nitro-L-arginine (LNA) feeding on the endothelial function in isolated coronary arteries from stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar-Kyoto (WKY) rats were studied. 2. A diet containing LNA (0.02%) was given to male SHRSP and WKY at 6 weeks of age and the coronary arteries were dissected on the 10th day of feeding. 3. In the SHRSP and WKY fed the LNA-free diet, acetylcholine (ACh) relaxed the precontracted ring segments of the coronary artery with intact endothelium in a dose-dependent manner. The reactivity was stronger in the WKY than in the SHRSP. However, the ACh-induced relaxation after the LNA-feeding was significantly stronger in the coronary arteries from the WKY than in those from the SHRSP. 4. The relaxation induced by the calcitonin gene-related peptide (CGRP) was endothelium-dependent and endothelium-independent. The degree of the response in the rats fed the LNA-containing diet was not significantly different from that in the rats fed the LNA-free diet. 5. The vasodilator response induced by sodium nitroprusside (SNP) was dose-dependent and similar in the rats fed the LNA containing diet and the LNA-free diet. 6. These findings indicate that chronic LNA feeding markedly impaired the endothelial nitric oxide formation in the coronary artery from young SHRSP.
Kajimoto
N
N
Department of Pharmacology, Kinki University School of Medicine, Osakasayama, Japan.
Ogawa
H
H
Suzuki
A
A
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects* / Q000503:physiopathology; D004032:Diet; D004730:Endothelium, Vascular / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D019335:Nitroarginine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D004791:Enzyme Inhibitors; D019335:Nitroarginine; D019001:Nitric Oxide Synthase