A novel device for measuring the effect of cholesterol on the release of oxygen from red blood cells into myocardial tissue.
A novel method has been devised to measure the effect of cholesterol on the release of oxygen (O2) from the red blood cell (RBC) into a tailored environment, which can be made to mimic myocardial tissue. Cholesterol affects the cell membrane of the RBC and thus the release of O2 into tissue. While this is true of all tissue, the myocardium is especially sensitive because of its critical nature, its high O2 requirements, and the shortness of time that arterial blood spends in the muscle. Calculations are presented that show that the release time for O2 from RBCs is close to the residence time of the RBC in the coronary system. Sequential measurements of blood oxygen saturation (SO2) are made when oxygenated blood is subjected to conditions similar to those in the myocardium. The natural logarithm of the relative value of the SO2 at time t compared with the initial value of the SO2 can be fitted to a straight line whose slope is proportional to the parameters of the RBC membrane, the sample size, the hematocrit, and the diffusion parameters of the apparatus. This value is used to estimate the effects of cholesterol-lowering treatments on O2 release. This test will serve as a valuable adjunct to or replacement for stress tests in the evaluation of coronary artery disease, especially in patients whose physical conditions make standard stress testing painful or risky.
O'Dea
T
T
Department of Diagnostic Radiology Medical Physics Section, University of Minnesota, Mineapolis 55455, USA. odeat@msn.com
Menchaca
H
H
Shudy
J
J
Rohde
T
T
Michalek
V
V
Fuller
C
C
Buchwald
H
H
D000465:Algorithms; D000924:Anticholesteremic Agents / Q000494:pharmacology; D001698:Biomedical Engineering / Q000295:instrumentation*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002784:Cholesterol / Q000502:physiology*; D003327:Coronary Disease / Q000175:diagnosis; D004058:Diffusion; D004867:Equipment Design; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006400:Hematocrit; D006801:Humans; D008954:Models, Biological; D008955:Models, Cardiovascular; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010949:Plasma; D018401:Sample Size; D013997:Time Factors
D000924:Anticholesteremic Agents; D002784:Cholesterol; D010100:Oxygen