J Vet Intern Med. 2026 May 4;40(3):aalag079. doi: 10.1093/jvimsj/aalag079.
ABSTRACT
BACKGROUND: Information on the classical and alternative circulating renin-angiotensin-aldosterone systems (RAAS) in cats with non-hypertensive chronic kidney disease (NHT-CKD) or systemic arterial hypertension (SAH) is limited. Age and diet affect the RAAS.
HYPOTHESIS/OBJECTIVES: To compare serum equilibrium concentrations of angiotensin peptides and aldosterone in healthy cats and cats with NHT-CKD or untreated SAH, and to evaluate changes in these concentrations in hypertensive cats administered amlodipine.
ANIMALS: Client-owned cats with NHT-CKD (serum creatinine ≥ 1.6 mg/dL, systolic blood pressure [SBP] < 160 mmHg; n = 17), SAH (SBP ≥ 160 mmHg or ≥ 150 mmHg with hypertensive ocular lesions; n = 6), or normal SBP (<140 mmHg) and kidney function (n = 17).
METHODS: Prospective, single-center, observational study. Cats underwent indirect SBP measurement and clinicopathologic analyses. Serum was obtained contemporaneously in all cats, and after 2-4 weeks of amlodipine therapy in hypertensive cats, for evaluation of angiotensin I, II, III, IV, 1-5, and 1-7, and aldosterone.
RESULTS: Adjusting for diet, age, or both modified the conclusions of statistical comparisons for several variables. Mean serum angiotensin I, II, and III concentrations were lower in cats with untreated SAH vs healthy controls across unadjusted and diet-, age-, or both diet- and age-adjusted linear mixed models (geometric mean [95% CI] angiotensin I, 9.02 [3.05-26.62] vs 29.78 [21.15-41.94] pmol/L; angiotensin II, 33.63 [12.25-92.26] vs 124.24 [90.52-170.51] pmol/L; angiotensin III, 1.56 [0.88-2.79] vs 7.96 [5.35-11.86] pmol/L; all P ≤ .038). Controlling for diet but not age, angiotensin II (P = .043) and III (P = .019) were also lower in cats with NHT-CKD vs controls. All angiotensin peptides, except for angiotensin IV, significantly increased in hypertensive cats during amlodipine therapy. Serum aldosterone did not differ between groups, or before and after amlodipine in hypertensive cats.
CONCLUSIONS AND CLINICAL IMPORTANCE: Evidence of circulating RAAS activation in cats with NHT-CKD or untreated SAH was not found.
PMID:42117720 | DOI:10.1093/jvimsj/aalag079