Chemomechanics of altered perfusion pressure in rat hearts.
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.
Watters
T A
TA
Department of Medicine (Cardiology), University of California, San Francisco.
Botvinick
E
E
Parmley
W W
WW
Wu
S
S
Wikman-Coffelt
J
J
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
D010710:Phosphates; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate