Effects of ioxaglate to blood rheology

Almen and Aspelin have shown that the use of non-ionic radio contrast media allows to increase the iodine concentration (which is desirable because of its effect on radio opacity) without a very large increase in osmolarity (which is undesirable because it impaires the fluidity of erythrocytes). This latter effect can also be diminished by reducing the osmolarity of a dimeric contrast medium as it has been achieved by incorporating more iodine atoms into the molecule in the case of Ioxaglate (Hexabrix). In various microrheological test systems, the fluidity of packed red cell suspension, the corrected filtration rate though 5 μm pores and the relative apparent viscosity of blood - contrast media mixtures (1 to 50% concentration) were determined in experiments comparing this compound with Urografin 76 of the same iodine content. In all systems, the former showed lesser rheological effects. In whole blood viscometry, this can be detected only after appropriate corrections for the effects of the two contrast media on hematocrit and plasma viscosity. Owing to a more pronounced water shift from the cells to the plasma, Urografin tends to reduce the viscosity of the plasma-contrast media mixture. The concomitant reduction in MCV and hematocrit level tends to screen the macrorheological effect of the dehydrated cells becomes immediately obvious when the viscometric data are corrected for hematocrit value and plasma viscosity effects. (orig.)