Table of Contents:
After a short discussion about the methods of the blood volume determination and the conventional methods using Cr-51-erythrocytes as well as the homologous rapid method with labelled preserved blood, the development of an autologous rapid method is described. The latter is based upon an ion exchanger and makes it possible to label the patient's own erythrocytes in approximately ten minutes. The first section discussing the determination of Cr-51-ery-vita data indicates the importance of an increased Cr-uptake of aging erythrocytes. The data obtained from centrifuges erythrocytes of different ages display a specific shape Cr-51-vita-curva which is only partly explained by a Cr-51-elution. Different methods of converting the Cr-51-vitas in the erythrocyte's mid life cycle and the nature of these curves are discussed. This report discusses the importance of the model of POLLYCOVE for the investigation of iron metabolism with Fe-59. The difficulties encountered in determination of values are discussed. The slow disappearance rate and the very low specific activity of the plasma iron was therefore determined a few days following the injection of Fe-59 in a 24 hour sample of urine subsequent to an i. v. injection of an iron eliminating substance (desferrioxamine). The curve of utilization is described by an equation which not only permits measurement of the conventional disappearance rate but also the determination of the iron pool of erythroblasts by a routine method. The formulated equations consider the influence of the migration of iron into the RES as well as the fact that – when a strong hemolysis is present – the curve is dependent upon destruction, not production, of erythrocytes. A procedure for the study of erythrokinetics simultaneously using Cr-51-erythrocytes and Fe-59 is discussed. A method is presented, which permits the analysis of previous information which is obtained without knowledge of the plasma iron specific activity. This was accomplished with the aid of the utilization curve according to the model of POLLYCOVE. By improving the method of measurement, only 0.1 ml of blood was required. The advantage of the measurement of low specific activities in urine is demonstrated. Interesting results of a familial hemolytic jaundice are given as an example of the simultaneous surface measurement.