Immunological evaluation of blood contamination in tissue distribution studies

An original, simple and economical method allowing the evaluation of blood contamination in tissue distribution studies is described. This method is based on the immunochemical determination of the amount of serum albumin present in tissue samples as a quantitative measurement of blood contamination, using a single radial immunodiffusion technique according to Mancina et al. Two pharmacokinetic studies we have performed in mice for different research purposes illustrate the crucial importance of the correction for blood contamination in the exact interpretation of the tissue uptake of a given compound. We have indeed clearly demonstrated first in the development of drug-carrier complexes in targeted cancer chemotherapy and second in the study of receptor-mediated clearance of glycoproteins from the plasma that the blood contamination, if not taken into account, can greatly alter the data of uptake by target organs. Our method is thus particularly useful in in vivo pharmacokinetic studies and is moreover not restricted to one animal species.