title: Myocardial oxygen tension in isolated erythrocyte-perfused rat hearts and comparison with crystalloid media.
abstract: The isolated heart, typically perfused with crystalloid media equilibrated with >/=95% O2 to ensure adequate myocardial oxygen tension, is commonly used to study cardiac function. When hemoglobin is available for oxygen transport, equilibration with 21% O2 is considered adequate to meet metabolic demands. This study presents the measurement of myocardial pO2 in isolated hearts perfused with an erythrocyte suspension. Baseline myocardial pO2 in erythrocyte-perfused hearts was 16.4+/-3.5 mmHg (mean+/-s.e.). When compared to previous measurements of myocardial pO2 in isolated hearts perfused with crystalloid media, the use of erythrocyte suspensions resulted in a 10-fold lower level of myocardial pO2, while avoiding very low and high values. The standard use of 95% oxygen with crystalloid results in myocardial levels of oxygen far above those usually found in the presence of hemoglobin and room air.
authors.affiliation: Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Friedman
authors.forename: O Y
authors.initials: OY
authors.lastname: Grinberg
authors.forename: S A
authors.initials: SA
authors.lastname: Grinberg
authors.forename: H M
authors.initials: HM
authors.lastname: Swartz
mesh_terms: D000818:Animals; D000077324:Crystalloid Solutions; D004912:Erythrocytes / Q000502:physiology*; D066298:In Vitro Techniques; D007552:Isotonic Solutions; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D010477:Perfusion; D010952:Plasma Substitutes / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D010100:Oxygen