Survey of atrial natriuretic peptide (ANP) plasma concentration in horses with pulmonic valve regurgitation

Atrial natriuretic peptide (ANP) is secreted by cardiac myocytes and it`s plasma concentration often increases in patients with cardiovascular disease in response to blood volume expansion and stretching of cardiac chambers. Increase in plasma concentration of ANP (CpANP) has been proved in humans with cardiac diseases and horses with left-sided valvular disease. This study aimed to investigate plasma ANP level in horses with pulmonic valve regurgitation and its association with echocardiographic parameters. Clinical and echocardiographic examinations were performed on several jumping horses in the equestrian clubs of Tehran, Iran. 11 horses with pulmonic valve regurgitation were identified by echocardiographic examination and were included in the case group (Group A), and 14 healthy horses were taken as the control group (Group B). Then, B-Mode, M-Mode and doppler echocardiographic parameters were measured and compared between the two groups. Blood samples from jugular vein were collected in tubes and were transferred to laboratory.CpANP was measured by Sandwich ELISA method using a horse specific kit.CpANP of horses in group1 and group2 were 6.39±2.87pg/ml and 4.78±2.45 pg/ml respectively, but no significant differences were observed.Except for right ventricular internal diameter, other echocardiographic parameters were not significantly different between the two groups.CpANP was significantly correlated to systolic right ventricle length and left ventricular width. In conclusion no significant differences were observed between CpANP of healthy horses and horses with pulmonic regurgitation. Based on the Correlation between CpANP and right ventricle length, an elevation in CpANP might be expected in severe pulmonic regurgitation with change in ventricle`s dimensions.