Effects of Light Exposure on the Release of Oxygen from Hemoglobin in a Red Blood Cell Suspension

Abstract

EFFECTS OF LIGHT EXPOSURE ON THE RELEASE OF OXYGEN FROM HEMOGLOBIN IN A RED BLOOD CELL SUSPENSION By: Tanikka D. Toler A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at the Medical College of Virginia Campus, Virginia Commonwealth University Virginia Commonwealth University, 2008 Advisor: Roland N. Pittman, Ph.D. Department of Physiology and Biophysics The main function of the cardiovascular system is to deliver a sufficient quantity of oxygenated blood to the tissues, cells, and organs of the body in order to provide the cells with essential nutrients for metabolism and for the removal of waste products. All cells require and utilize oxygen. Oxygen is transported to various cells and tissues via red blood cells flowing through the microcirculation of an organism. Measurement of oxygen transport in the microcirculation has shown that about ten times more oxygen appears to leave the blood of arterioles than can be accounted for by diffusion. One possibility to explain the high oxygen loss is an increased release of oxygen due to exposure of blood to light. In the present in vitro study the release of oxygen from red blood cells was measured during exposure of the sample to light by monitoring the change in PO2 of the suspension during light exposure. A PO2 electrode was calibrated using PBS solution and utilized to monitor the change in current in the present study. Red blood cell suspensions were made using blood withdrawn from male SpragueDawley rats. The red blood cell suspension was placed in a closed sample chamber and exposed to light for 5 minutes. A method to correct for the drift of the PO2 electrode and