Atrial Natriuretic Peptide and Cardiovascular Diseases in Dogs and Cats

The term biomarker encompasses various biological indicators that objectively reflect a patient's medical status with precision and reproducibility. These indicators range from basic measurements like pulse and blood pressure to more intricate laboratory tests. Cardiac markers are crucial for accurate and prompt diagnosis of heart diseases in animals. Given the challenge of diagnosing cardiac diseases in small animals due to nonspecific clinical signs, cardiac markers provide quantitative indicators of biological processes. These markers include cardiac troponins for myocardial injury, natriuretic peptides for myocardial function, lipoproteins for serum homeostasis, and markers for inflammation of the cardiovascular system. Among natriuretic peptides, atrial natriuretic peptide (ANP) has emerged as a significant tool in diagnosing and monitoring cardiac diseases. ANP, primarily synthesized in cardiac atria, regulates salt and fluid excretion, counteracts vasoconstriction, and inhibits the renin-angiotensin-aldosterone system, contributing to the maintenance of cardiovascular homeostasis. Additionally, it functions as a biomarker for ventricular hypertrophy and congestive heart failure (CHF) in animals. Furthermore, it protects against hypertension and cardiac remodeling by demonstrating antagonism to the same system. This review addresses the definition of biomarkers within the context of molecular biology, elucidates their multifaceted functions in the animal organism in light of integrative physiology, and explores the pathologies correlated with ANP, with an emphasis on its etiopathogenesis and clinical manifestations.