Acidosis, cardiac stunning and its prevention by oxygen.
When during aerobic perfusion of the 5 Hz paced rat Langendorff heart, under constant aortic pressure of 8.3 kPa, the pH of the medium is changed from 7.5 to 7.0 a short period of positive inotropy is followed by a dramatic loss of contractility. The hearts, rapidly frozen after 10 min pH 7.0 perfusion, show moderate loss of high-energy phosphates and accumulation of lactate and glycerol-3-phosphate, indicative of tissue anaerobiosis. This can be overcome by including fluorocarbon, an O2 vehicle, in the media. The transient positive inotropy is interpreted as H(+)-induced release of plasmalemma-bound Ca2+ into the cytosol. The accompanying morphologic alterations are as described in this issue by Vandeplassche and Borgers (1990) and by Verkleij et al. (1990).
Hülsmann
W C
WC
Thorax Centre, Erasmus University, Rotterdam, NL.
de Wit
L E
LE
D000138:Acidosis / Q000517:prevention & control*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002304:Cardiac Pacing, Artificial; D002462:Cell Membrane / Q000378:metabolism; D005466:Fluorocarbons / Q000494:pharmacology; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology*; D051381:Rats
D005466:Fluorocarbons; D010100:Oxygen; D002118:Calcium