Franol effect on the labelling of erythrocytes with Tc-99m

The aim of this investigation is to study if franol, is capable to interfere with the binding to technetium-99m (Tc-99m) on blood elements. Blood with heparine was withdraw from Wistar rats were incubated with franol solution (1 hour). Then, Stannous chloride (Sn CL2) solutions in different concentrations were added. After 1 hour Tc-99m (3.7 MBq), was added and the incubation continued for another 10 min. Blood was centrifuged and plasma (P) and blood cells (BC) were isolated. Aliquots of P or BC were precipitated in trichloroacetic acid 5%, centrifuged and soluble (SF) and insoluble fractions (IF) were separated. The % rad in P, BC, IF from BC and P were calculated. Franol altered (i) the % rad in P and BC only to Sn CL2 concentration of 12 ug/ml, the % rad in IF-P only to Sn CL2 concentration of 0.06 ug/mg and (increased the % rad in IF-BC to Sn CL2 concentrations of 1.2 and 12 ug/ml. The franol effect can be explained by an action of these substances (ephedrine and theophylline). (author)