title: Effects of L-arginine on systemic and renal haemodynamics in conscious dogs.
abstract: 1. The effects of L-arginine on systemic and renal haemodynamics were investigated in conscious dogs. L-Arginine was administered intravenously at doses of 15 and 75 mumol min-1 kg-1 for 20 min. 2. Mean arterial blood pressure, heart rate and cardiac output were not changed significantly by L-arginine infusion. However, L-arginine infusion induced a significant elevation of renal blood flow from 50 +/- 3 to 94 +/- 12 ml/min (means +/- SEM, P less than 0.01). 3. Simultaneous infusion of NG-monomethyl-L-arginine (0.5 mumol min-1 kg-1) significantly inhibited the increase in renal blood flow produced by L-arginine (15 mumol min-1 kg-1) without significant changes in mean arterial blood pressure or heart rate. 4. Pretreatment with atropine completely inhibited the L-arginine-induced increase in renal blood flow, whereas pretreatment with indomethacin attenuated it (63 +/- 4 versus 82 +/- 10 ml/min, P less than 0.05). 5. A continuous infusion of L-arginine increased renal blood flow in the intact kidney (55 +/- 3 versus 85 +/- 9 ml/min, P less than 0.05), but not in the contralateral denervated kidney (58 +/- 3 versus 56 +/- 4 ml/min, P greater than 0.05). 6. These results suggest that intravenously administered L-arginine produces an elevation of renal blood flow, which may be mediated by facilitation of endogenous acetylcholine-induced release of endothelium-derived relaxing factor and vasodilatory prostaglandins.
authors.affiliation: Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Murakami
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: A
authors.initials: A
authors.lastname: Ichihara
authors.forename: M
authors.initials: M
authors.lastname: Naitoh
authors.forename: H
authors.initials: H
authors.lastname: Nakamoto
authors.forename: T
authors.initials: T
authors.lastname: Saruta
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007213:Indomethacin / Q000494:pharmacology; D007668:Kidney / Q000098:blood supply / Q000187:drug effects* / Q000294:innervation; D008297:Male; D012039:Regional Blood Flow / Q000187:drug effects; D019323:omega-N-Methylarginine
chemical_list: D019323:omega-N-Methylarginine; D001285:Atropine; D001120:Arginine; D007213:Indomethacin