title: Effect of acute volume expansion associated with salt load on the profile of plasma angiotensins in rats.
abstract: We measured the changes produced in renin and the peptide components of the circulating renin-angiotensin system by acute volume expansion alone or associated with salt load in rats. With both maneuvers, there was a decrease of plasma renin activity (PRA) and plasma angiotensin (Ang) concentrations, but the changes were more pronounced in the salt-load group. In contrasting to Ang I and Ang II, plasma Ang-(1-7) concentration decreased significantly only within 60 min of 5.0% NaCl infusion (19.5 +/- 2.9 vs 30.5 +/- 1.9 pg/ml in the control group). As expected, plasma vasopressin increased markedly in the animals submitted to acute salt load (144.0 +/- 42.0 vs 5.0 +/- 0.2 pg/ml in the control group). The dissociation between the changes in plasma Ang-(1-7) and that of other plasma angiotensins is consistent with our previous studies using chronic salt load, and suggests that during acute volume expansion associated with salt load Ang I is preferentially converted to Ang-(1-7). In contrast to vasopressin, however, plasma Ang-(1-7) concentration increased only after chronic salt load, suggesting that this angiotensin may be more involved with long-term mechanisms of control of hydromineral balance.
authors.affiliation: Departamento de Fisiologia and Biofísica, Universidade Federal de Minas, Gerais, Belo Horizonte, MG, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Carvalho
authors.forename: L M
authors.initials: LM
authors.lastname: Botelho
authors.forename: L J
authors.initials: LJ
authors.lastname: Greene
authors.forename: R A
authors.initials: RA
authors.lastname: Santos
mesh_terms: D000803:Angiotensin I / Q000097:blood; D000804:Angiotensin II / Q000097:blood; D000809:Angiotensins / Q000097:blood*; D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood; D008297:Male; D010446:Peptide Fragments / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000502:physiology; D012965:Sodium Chloride / Q000008:administration & dosage; D014882:Water-Electrolyte Balance / Q000502:physiology*
chemical_list: D000809:Angiotensins; D010446:Peptide Fragments; D000804:Angiotensin II; D001127:Arginine Vasopressin; D012965:Sodium Chloride; D000803:Angiotensin I; D012083:Renin; C118790:angiotensin I (1-7)