Open AccessThe Renin‐Angiotensin‐Aldosterone System in Greyhounds and Non‐Greyhound Dogs
Author(s) -
Martinez J.,
Kellogg C.,
Iazbik M.C.,
Couto C.G.,
Pressler B.M.,
Hoepf T.M.,
Radin M.J.
Publication year - 2017
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.14720
Subject(s) - medicine , aldosterone , endocrinology , plasma renin activity , blood pressure , radioimmunoassay , renin–angiotensin system , creatinine , urine
Background The renin‐angiotensin‐aldosterone system ( RAAS ) regulates blood pressure, electrolyte homeostasis, and renal function. Blood pressure, serum sodium concentrations, and urinary albumin excretion are higher in Greyhounds than other purebred and mixed‐breed dogs. Hypothesis Alterations in the RAAS in Greyhounds are associated with hemodynamic and clinicopathologic differences observed in the breed. Animals Clinically healthy Greyhound and non‐Greyhound dogs consecutively enrolled as blood donors (n = 20/group). Methods Prospective study. Standard chemical analysis was performed on serum and urine. Serum angiotensin‐converting enzyme ( ACE ) activity was determined by fluorometric assay. All other RAAS hormones were determined by radioimmunoassay. Symmetric dimethylarginine ( SDMA ) was measured by immunoassay. Measurements were compared to blood pressure and urine albumin concentration. Data are presented as mean ± SD or median, range. Results Serum creatinine (1.5 ± 0.2 vs 1.0 ± 0.1 mg/ dL , P < .001), sodium (149, 147–152 vs 148, 146–150 mE q/L, P = .017), and SDMA (16.1 ± 2.9 vs 12.2 ± 1.8 μg/ dL , P < .001) were significantly higher in Greyhounds versus non‐Greyhounds, respectively. Plasma renin activity (0.69, 0.10–1.93 vs 0.65, 0.27–2.93 ng/ mL /h, P = .60) and ACE activity (4.5, 2.1–8.5 vs 4.6, 2.1–11.4 activity/ mL ; P = .77) were similar between groups and did not correlate with higher systolic pressures and albuminuria in Greyhounds. Plasma aldosterone concentration was significantly lower in Greyhounds versus non‐Greyhounds (11, 11–52 vs 15, 11–56 pg/ mL , respectively, P = .002). Conclusions and clinical importance Basal RAAS activation did not differ between healthy Greyhounds and non‐Greyhounds. Lower aldosterone concentration in Greyhounds is an appropriate physiologic response to higher serum sodium concentration and blood pressure, suggesting that angiotensin II effects in the renal tubule predominate over those of aldosterone.