Cardiac output in four-, five-, and six-week-old broilers, and hemodynamic responses to intravenous injections of epinephrine

Department of Poultry Science, University of Arkansas, Fayetteville 72701, USA. rwideman@comp.uark.edu

Female broilers were evaluated at 4, 5, and 6 wk of age (1.2, 1.8, and 2.3 kg BW, respectively) to assess changes in cardiac output and related hemodynamics associated with BW gain, and to evaluate cardiopulmonary hemodynamic adjustments occurring secondary to i.v. injections of epinephrine (0.1 mg/ kg BW). Cardiac output increased with BW (253, 348, and 434 mL/min at 4, 5, and 6 wk, respectively) due to increases in stroke volume (0.70, 1.03, and 1.33 mL/beat) that more than compensated for reductions in heart rate (362, 337, and 328 bpm). Normalization for BW eliminated the differences in cardiac output and stroke volume. Increases in cardiac output were not associated with age- or BW-related increases in mean systemic arterial pressure (101.5, 108.6, and 108.0 mm Hg) due to corresponding reductions in total peripheral resistance (0.41, 0.32, and 0.26 relative resistance units). Epinephrine initially triggered immediate (within 90 s) threefold increases in total peripheral resistance and pulmonary vascular resistance, which, in turn, increased the systemic arterial pressure and pulmonary arterial pressure in spite of concurrent reductions in cardiac output that were associated with diminished venous return and dependent reductions in stroke volume and heart rate. Within 150 s after epinephrine injection, the systemic and pulmonary vascular resistances returned to preinjection control levels. By 300 s postinjection, stroke volume and heart rate increased, causing cardiac output to rise above preinjection control levels, which, in turn, elicited variable pulmonary arterial pressure responses apparently reflecting individual variability in the capacity for flow-dependent pulmonary vasodilation. These studies demonstrate that chronic (age- and BW-related) and acute (epinephrine-induced) changes in cardiac output in broilers reflect complex interactions among hemodynamic variables that include stroke volume, heart rate, and systemic and pulmonary vascular resistances.

This article has been cited by other articles:

				S. Druyan, D. Shinder, A. Shlosberg, A. Cahaner, and S. Yahav Physiological parameters in broiler lines divergently selected for the incidence of ascites Poult. Sci., September 1, 2009; 88(9): 1984 - 1990. [Abstract] [Full Text] [PDF]

				C. A. Ruiz-Feria Concurrent supplementation of arginine, vitamin E, and vitamin C improve cardiopulmonary performance in broilers chickens Poult. Sci., March 1, 2009; 88(3): 526 - 535. [Abstract] [Full Text] [PDF]

				A. G. Lorenzoni and R. F. Wideman Jr. Intratracheal Administration of Bacterial Lipopolysaccharide Elicits Pulmonary Hypertension in Broilers with Primed Airways Poult. Sci., April 1, 2008; 87(4): 645 - 654. [Abstract] [Full Text] [PDF]

				A. G. Lorenzoni, N. B. Anthony, and R. F. Wideman Jr. Transpulmonary Pressure Gradient Verifies Pulmonary Hypertension is Initiated by Increased Arterial Resistance in Broilers Poult. Sci., January 1, 2008; 87(1): 125 - 132. [Abstract] [Full Text] [PDF]

				S. Stebel and R. F. Wideman Pulmonary Hemodynamic Responses to Intravenous Prostaglandin E2 in Broiler Chickens Poult. Sci., January 1, 2008; 87(1): 138 - 145. [Abstract] [Full Text] [PDF]

				A. G. Lorenzoni and R. F. Wideman Jr. Inhaling One Hundred Percent Oxygen Eliminates the Systemic Arterial Hypoxemic Response of Broilers to Intravenous Microparticle Injections Poult. Sci., January 1, 2008; 87(1): 146 - 154. [Abstract] [Full Text] [PDF]

				R. F. Wideman, M. E. Chapman, K. R. Hamal, O. T. Bowen, A. G. Lorenzoni, G. F. Erf, and N. B. Anthony An Inadequate Pulmonary Vascular Capacity and Susceptibility to Pulmonary Arterial Hypertension in Broilers Poult. Sci., May 1, 2007; 86(5): 984 - 998. [Abstract] [Full Text] [PDF]

				A. G. Lorenzoni and C. A. Ruiz-Feria Effects of Vitamin E and L-Arginine on Cardiopulmonary Function and Ascites Parameters in Broiler Chickens Reared Under Subnormal Temperatures Poult. Sci., December 1, 2006; 85(12): 2241 - 2250. [Abstract] [Full Text] [PDF]

				O. T. Bowen, R. F. Wideman, N. B. Anthony, and G. F. Erf Variation in the Pulmonary Hypertensive Responsiveness of Broilers to Lipopolysaccharide and Innate Variation in Nitric Oxide Production by Mononuclear Cells Poult. Sci., August 1, 2006; 85(8): 1349 - 1363. [Abstract] [Full Text] [PDF]