title: L-arginine prevents corticotropin-induced increases in blood pressure in the rat.
abstract: In this study we examined whether L-arginine treatment could prevent corticotropin (ACTH)-induced increases in blood pressure in the Sprague-Dawley rat. Sixty rats were randomly divided into six groups (n = 10): sham injection, ACTH injection (0.5 mg/kg per day in divided doses), L-arginine (0.6%) in food plus sham injection, L-arginine plus ACTH treatment, D-arginine (0.6%) in food plus sham injection, and D-arginine plus ACTH. Systolic pressure, water intake, urine volume, body weight, plasma and urinary electrolytes, and serum corticosterone concentrations were measured. ACTH increased systolic pressure (from 127 +/- 2 to 165 +/- 6 mm Hg, P < .001), water intake, and urine volume and decreased body weight body weight. L-Arginine reduced ACTH-induced blood pressure rises (130 +/- 3 mm Hg, P < .001) but had no effect on blood pressure in sham-treated rats. D-Arginine did not affect blood pressure in sham-treated rats, and systolic pressure in D-arginine+ACTH-treated rats was similar to that of ACTH-treated rats. L-Arginine decreased serum corticosterone concentrations in sham-treated rats (424 +/- 42 versus 238 +/- 25 ng/mL, P < .01), but D-arginine had no effect. However, both drugs decreased serum corticosterone concentrations in ACTH-treated rats (1071 +/- 117 versus 739 +/- 95 and 695 +/- 72 ng/mL for L- and D-arginine, respectively; both P < .05). As L-arginine but not D-arginine prevented ACTH-induced increases in blood pressure in Sprague-Dawley rats and both L- and D-arginine reduced serum corticosterone concentrations in ACTH-treated rats, the effects of L-arginine in preventing ACTH-induced hypertension were not simply a consequence of decreased corticosterone secretion.
authors.affiliation: Department of Medicine, St George Hospital, University of New South Wales, Sydney, Australia.
authors.forename: S W
authors.initials: SW
authors.lastname: Turner
authors.forename: C
authors.initials: C
authors.lastname: Wen
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: J A
authors.initials: JA
authors.lastname: Whitworth
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects; D000324:Adrenocorticotropic Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D006321:Heart / Q000187:drug effects; D006973:Hypertension / Q000139:chemically induced / Q000517:prevention & control*; D007668:Kidney / Q000187:drug effects; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011188:Potassium / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012964:Sodium / Q000097:blood; D013997:Time Factors
chemical_list: D000324:Adrenocorticotropic Hormone; D001120:Arginine; D012964:Sodium; D011188:Potassium