title: Regional blood flow in Dahl-Iwai salt-sensitive rats and the effects of dietary L-arginine supplementation.
abstract: The purpose of the present study was to determine 1) whether different organs undergo similar increase in vascular resistance in Dahl-Iwai salt-sensitive (S) rats, and 2) the effects of chronic oral L-arginine supplementation on the regional hemodynamics in S rats. Male 6-wk-old S rats and salt-resistant (R) rats were maintained on an 8% NaCl chow for 4 wk. One group (S or R rats) was maintained on tap water and the other group (S/Arg or R/Arg rats) received tap water containing L-arginine at a concentration of 1.5%. Organ blood flow and cardiac output were measured with microspheres in the conscious condition. Mean blood pressure in S, S/Arg, R, and R/Arg rats was 159 +/- 5, 138 +/- 3, 111 +/- 4, and 112 +/- 4 mmHg, respectively. Urinary excretion of protein and albumin in S/Arg rats was significantly suppressed compared with S rats. Concerning regional hemodynamics, the flow rate of the kidney was lower in S rats than in R rats, but there were no differences between S and R rats in the flow rates of the brain, heart, lung, liver, spleen, intestine, skeletal muscle, and skin. Thus the renal blood flow was solely reduced in S rats on a high-salt diet. The flow rate of the kidney in S/Arg rats was maintained at a higher level compared with that of S rats. L-Arginine treatment tended to produce a recovery in the urinary excretion of guanosine 3',5'-cyclic monophosphate in S rats, but had no effect in R rats. Thus the supplementation of L-arginine prevented the increase in blood pressure in S rats on a high-salt diet and normalized the abnormality of renal hemodynamics accompanying salt-induced hypertension.
authors.affiliation: Department of Pharmacology, Kagawa Medical School, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Tomohiro
authors.forename: S
authors.initials: S
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: He
authors.forename: Y
authors.initials: Y
authors.lastname: Fujisawa
authors.forename: A
authors.initials: A
authors.lastname: Nishiyama
authors.forename: K
authors.initials: K
authors.lastname: Kiyomoto
authors.forename: Y
authors.initials: Y
authors.lastname: Aki
authors.forename: T
authors.initials: T
authors.lastname: Tamaki
authors.forename: Y
authors.initials: Y
authors.lastname: Abe
mesh_terms: D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure; D001921:Brain / Q000098:blood supply; D002302:Cardiac Output; D003326:Coronary Circulation; D005527:Food, Fortified; D006339:Heart Rate; D006439:Hemodynamics; D007421:Intestine, Small / Q000098:blood supply; D007668:Kidney / Q000098:blood supply; D008099:Liver / Q000098:blood supply; D008297:Male; D009928:Organ Specificity; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects*; D012982:Sodium, Dietary / Q000494:pharmacology; D013045:Species Specificity; D013737:Testis / Q000098:blood supply; D014655:Vascular Resistance
chemical_list: D012982:Sodium, Dietary; D001120:Arginine