Investigation of vascular endothelial growth factor (VEGF) activity in ascites syndrome of meat type chicken

Broilers are susceptible to ascites syndrome, a condition associated with pulmonary hypertension, right ventricular failure, increased central venous pressure, passive congestion of the liver, and accumulation of serous fluids in the abdominal cavity. Vascular Endothelial Growth Factor is a powerful mediator that increases vascular permeability, which has a key role in physiological and pathological angiogenesis and edema formation. This study aimed to investigate by using immunohistochemistry (IHC), and ELISA methods the possible role of VEGF in acute and chronic ascites in broilers induced by hypoxia in a hypobaric chamber as a high altitude model. Immunohistochemistry (IHC) staining showed positive staining in the bronchial epithelium, vascular endothelium, adventitia and the connective tissue around blood vessels also stained positively in the lungs of a limited number of animals. There was strong positivity of IHC staining in the hepatocytes. Myocardial cells and elastic fibers were stained positive in the hearts of almost all animals. Tubular epithelium and glomeruli were stained positively in kidney sections and neurons were stained positively in brain tissue in almost all animals. Using semi-quantitative IHC scoring of VEGF was more intense in the acute form of ascites compared to the control group; stainings were more intense by 3.28 times in the heart, 1.61 times in the lungs, 1.54 times in the kidneys, and 1.39 times in the brain. Compared with the acute phase chronic ascites, showed more intense staining in the kidney by 2.27 times, in the heart 2.02 times, in the lungs 1.81 times, and in the brain 2.41 times. In the ELISA test, it was observed that the mean value of lung tissue lysates of animals with ascites in the chronic period (118.2 pg/ml) was higher than the control (114.8 pg/ml) and acute period (114.9 pg/ml). It was observed that the amount of VEGF in the ascites fluid of the ascites group animals was 4.1 times higher in the acute period (69.5 pg/ml) than in the chronic period (16.8 pg/ml). Accordingly, VEGF appears to be secreted more from somatic cells during ascites (specifically at the acute period of the ascites) and may play a role in the pathogenesis of the disease and edema formation.