title: Chemomechanics of altered perfusion pressure in rat hearts.
abstract: In an apex-ejecting isolated perfused working rat heart, as well as isovolumic preparations of rat hearts, perfusion pressure was studied independent of afterload. A decrease in perfusion pressure caused an immediate decrease in developed pressure (10s). There was a significant increase in free Pi and the phosphorylation potential after 20-30 min of perfusion at a reduced coronary flow induced by a reduction in perfusion pressure. Developed pressure decreased prior to the phosphorylation potential and inorganic phosphate; however, the phosphorylation set a limit to maximum work performance. At a perfusion pressure of 140 cm H2O and an afterload of 140 cm H2O, work imposed on the heart was maximum; there was no further increase in work.
authors: Department of Medicine (Cardiology), University of California, San Francisco.
authors: T A
authors: TA
authors: Watters
authors: E
authors: E
authors: Botvinick
authors: W W
authors: WW
authors: Parmley
authors: S
authors: S
authors: Wu
authors: J
authors: J
authors: Wikman-Coffelt
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003326:Coronary Circulation; D004734:Energy Metabolism; D006321:Heart / Q000502:physiology*; D009682:Magnetic Resonance Spectroscopy; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D010477:Perfusion; D010710:Phosphates / Q000378:metabolism; D011312:Pressure; D051381:Rats; D013318:Stroke Volume
chemical_list: D010710:Phosphates; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate