Low-O2 affinity erythrocytes improve performance of ischemic myocardium
2002 (English)In: Journal of applied physiology, ISSN 8750-7587, Vol. 92, no 3, 1267-1276 p.Article in journal (Refereed) Published
O2 transport and O2 diffusion interact in providing O2 to tissue, but the extent to which diffusion may be critical in the heart is unclear. If O2 diffusion limits mitochondrial oxygenation, a change in blood O2 affinity at constant total O2 transport should alter cardiac O2 consumption (VO2) and function. To test this hypothesis, we perfused isolated isovolumically working rabbit hearts with erythrocytes at physiological blood-gas values and P50 (PO2 required to half-saturate hemoglobin) values at Ph of 7.4 of 17 ▒ 1 Torr (2,3-bisphosphoglycerate depletion) and 33 ▒ 5 Torr (inositol hexaphosphate incorporation). When perfused at 40 and 20% of normal coronary flow, mean VO2 decreased from the control value by 37 and 46% (P < 0.001), and function, expressed as cardiac work, decreased by 38 and 52%, respectively (P < 0.001). Perfusion at higher P50 during low-flow ischemia improved VO2 by 20% (P < 0.001) and function by 36% (P < 0.02). There was also modest improvement at basal flow (P < 0.02 and P < 0.002, respectively). The improvement in VO2 and function due to the P50 increase demonstrates the importance of O2 diffusion in this cardiac ischemia model.
Place, publisher, year, edition, pages
2002. Vol. 92, no 3, 1267-1276 p.
blood oxygen affinity, oxygen dissociation curve, inositol hexaphosphate, isolated heart, rabbit
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-26391DOI: 10.1152/japplphysiol.00194.2001Local ID: 10928OAI: oai:DiVA.org:liu-26391DiVA: diva2:246940