Potential molecular mechanism of ascites syndrome in broilers

Ascites syndrome in broilers (AS), also known as broiler pulmonary hypertension syndrome (PHS), is a common nutritional and metabolic disease in commercial broilers. It is a disease characterised by a progressive increase in pulmonary artery pressure, followed by right ventricular hypertrophy, right heart failure and ultimately death. Diseased chickens with AS have characteristic lesions including right heart hypertrophy, ascites, pulmonary congestion and pulmonary oedema can be observed after opening the thoracic cavity. Pulmonary arterial hypertension (PAH) is a key link in the development of AS in broilers. Pulmonary artery vasoconstriction and pulmonary artery remodelling promote the development of AS. The AS is commonly influenced by a variety of mechanisms including hypoxia, endothelial dependency regulation, vascular active material imbalance, oxidative stress, inflammation, in situ thrombosis and genetic tendency. This review focuses on the regulation of vasoactive substances, oxidative stress, Hypoxia-inducible factors, immunomodulation and non-epigenetic phenomena on AS. The aim of this study is to review the current understanding of the pathogenesis of AS and to provide insights into the future development of this growing field for the control of AS in broiler chickens.