caa a22 4500 397569041 CHVBK 20180308164836.0 cr unu---uuuuu 161202e199612 xx s 000 0 eng 10.3382/ps.0751587 doi (NATIONALLICENCE)oxford-10.3382/ps.0751587 Cardio-Pulmonary Function During Acute Unilateral Occlusion of the Pulmonary Artery in Broilers Fed Diets Containing Normal or High Levels of Arginine-HCl [Elektronische Daten] [ROBERT F. WIDEMAN, YVONNE KOCHERA KIRBY, CAYE D. TACKETT, NATHAN E. MARSON, RONALD W. MCNEW] Cardio-pulmonary function was measured in male broilers reared on diets formulated to contain 1.5% arginine (NORMAL group) or 2.5% arginine (ARGININE group). A snare placed around the right pulmonary artery permitted acute shunting of the entire cardiac output (CO) through the left pulmonary artery, resulting in sustained increases in blood flow (BF) through the left lung in both groups. The unilateral increase in BF was accompanied by sustained increases in pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) in the NORMAL group. However, following initial transient increases in PAP and PVR in the ARGININE group, subsequent pulmonary vasodilation gradually reduced PVR, and thus PAP, in spite of the ongoing elevation in BF through the left lung. The capacity of the pulmonary vasculature in the ARGININE group to accommodate an increased BF at a normal PAP accounts for the previously reported lower incidence of pulmonary hypertension syndrome (PHS, ascites) in cold-stressed broilers fed supplemental dietary arginine. Hypoxemia and respiratory acidosis ensued rapidly in both groups after tightening the pulmonary artery snare, in spite of a compensatory increase in the respiratory rate. The gradual return of PVR and PAP to presnare levels in the ARGININE group did not eliminate the concurrent ventilation-perfusion mismatch caused by the increased rate of BF through the left lung. Tightening the pulmonary artery snare caused mean systemic arterial pressure (MAP) to drop from control levels of approximately 98 mm Hg to sustained hypotensive levels of approximately 65 mm Hg in both groups. This systemic hypotension was caused by decreases in CO and total peripheral resistance (TPR). The reductions in CO were caused by reductions in stroke volume (SV) rather than heart rate (HR), suggesting that acutely tightening the pulmonary artery snare increased PVR sufficiently to impede left ventricular filling. Accordingly, the maximum increment in PAP attainable by the right ventricle during acute increases in PVR apparently was inadequate to propel the entire CO through the pulmonary vasculature, setting the stage for the congestive right-sided pooling of blood routinely associated with PHS in broilers. © 1996 Poultry Science Association, Inc. Physiology and Reproduction nationallicence ascites nationallicence pulmonary hypertension nationallicence respiration nationallicence cardiovascular physiology nationallicence arginine nationallicence WIDEMAN ROBERT F. Department of Poultry Science and aut KIRBY YVONNE KOCHERA Department of Poultry Science and aut TACKETT CAYE D. Department of Poultry Science and aut MARSON NATHAN E. Department of Poultry Science and aut MCNEW RONALD W. Agricultural Statistics Laboratory, University of Arkansas, Fayetteville, Arkansas 72701 aut Poultry Science Oxford University Press 75/12(1996-12), 1587-1602 0032-5791 75:12<1587 1996 75 ps https://doi.org/10.3382/ps.0751587 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.3382/ps.0751587 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- WIDEMAN ROBERT F. Department of Poultry Science and aut NATIONALLICENCE 700 1- KIRBY YVONNE KOCHERA Department of Poultry Science and aut NATIONALLICENCE 700 1- TACKETT CAYE D. Department of Poultry Science and aut NATIONALLICENCE 700 1- MARSON NATHAN E. Department of Poultry Science and aut NATIONALLICENCE 700 1- MCNEW RONALD W. Agricultural Statistics Laboratory, University of Arkansas, Fayetteville, Arkansas 72701 aut NATIONALLICENCE 773 0- Poultry Science Oxford University Press 75/12(1996-12), 1587-1602 0032-5791 75:12<1587 1996 75 ps Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford