PHYSIOLOGY AND REPRODUCTION Taurine, Cardiopulmonary Hemodynamics, and Pulmonary Hypertension Syndrome in Broilers

ABSTRACT Previous studies have suggested cardiac taurine is released into the plasma in response to hypo-xemia (low blood oxygen levels) during the pathogenesis of pulmonary hypertension syndrome (PHS, ascites). In the present study, broilers reared under cool temperature conditions (16 C) were provided tap water (control group), tap water supplemented with taurine, or tap wa-ter supplemented with the taurine transport antagonist β-alanine. When compared with control values, taurine supplementation consistently elevated free taurine con-centrations in the plasma but not in cardiac tissues, whereas β-alanine supplementation consistently reduced free taurine concentrations in cardiac tissues but not in the plasma. Neither the incidence of PHS nor specific predictors of PHS susceptibility (electrocardiogram Lead II S-wave amplitude, % saturation of hemoglobin with oxygen, heart rate, right to total ventricular weight ratio) were affected by taurine or β-alanine supplementation. Cardiopulmonary hemodynamic evaluations were con-ducted to compare control and β-alanine supplemented broilers breathing room air or air containing 12 % oxygen (low oxygen challenge). While breathing room air, the β-alanine-supplemented broilers had higher baseline values for cardiac output (186.2 vs. 146.9 mL/min/kg BW) and pulmonary arterial pressure (27.4 vs. 22.4 mm Hg), similar values for mean systemic arterial pressure (100 vs. 10