Action

• Angiotensin-converting enzyme (ACE) inhibitors inhibit ACE (present in the endothelia of the small blood vessels of the lungs, kidneys and other tissues).
• ACE converts angiotensin I (a precursor molecule which is mainly inactive) to the hormone angiotensin II.
• ACE catalyses breakdown of bradykinin.
• Angiotensin II has several effects:
  • Contraction of vascular smooth muscle, producing vasoconstriction.
  • Stimulation of aldosterone secretion from the adrenal cortex.
  • Increased sodium reabsorption proximal renal tubuli.
  • Stimulation of hypertrophy of the myocardium and vascular smooth muscle.
  • Stimulation of thirst receptors in the brain.
  • Enhanced sympathetic adrenergic tone and increased release of noradrenaline from sympathetic nerve terminals.
  • Increases endothelin release, which might cause vasoconstriction.
  • Stimulation of vasopressin (antidiuretic hormone) release from posterior pituitary gland.

Effects

ACE Inhibitors available and their use in cats

Ramipril

ACE inhibitors and renal function

Use of diuretics with ACE inhibitors

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• MacDonald K, Kittleson M D, Larson R F et al (2006) The effect of Rampril on left ventricular mass, myocardial fibrosis, diastolic function, and plasma neurohormones in Maine Coon cats with familial hypertrophic cardiomyopathy without heart failure. JVIM 20 (5), 1093-1105 PubMed.
• Sturgess K (2004) The role of ACE inhibitors in the management of acquired heart disease in cats. UK Vet 9, 51-60.
• Davidson G, Horeish C (1999) Enalapril maleate. Comp Contin Educ Pract Vet 21 (12), 1118-1121 VetMedResource.
• Boswood A (1998) Rationale for the use of drugs in the treatment of cardiovascular disease. 2. Vasodilators. In Practice 20 (2), 55-63 VetMedResource.
• Rush J E, Freeman L M, Brown D J et al (1998) The use of enalapril in the treatment of feline hypertrophic cardiomyopathy. JAAHA 34 (1), 38-41 PubMed.
• Boswood A (1996) Rationale for the use of drugs in the treatment of cardiovascular disease. 1. Diuretics. In Practice 18 (10), 469-476 VetMedResource.

Other sources of information

• Bishop Y M (1996) Ed The Veterinary Formulary. Handbook of Medicines used in Veterinary Practice. 3rd edn. London: Royal Pharmaceutical Society of Great Britain and British Veterinary Association. pp 201-202. ISBN 0 85369 345 5.
• Wotton P R & Gruffydd-Jones T J (1994) The cardiovascular system. In: Feline Medicine and Therapeutics. 2nd edn. Eds E A Chandler, C J Gaskell & R M Gaskell. Oxford: Blackwell Scientific Publications. pp 412-413. ISBN 0 632 03361 4.