A novel device for measuring the effect of cholesterol on the release of oxygen from red blood cells

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 RBCs 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, 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 the myocardium. The natural logarithm of the relative value of the SO₂ at time t compared to 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 effect 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 condition make standard stress testing painful or risky