[Pharmacokinetics of angiographic contrast media]

The pharmaco-kinetics of angiographic contrast media in the extravascular space, which are largely unknown, were investigated experimentally in dogs. As part of a basic study, using radio-active contrast media, it was possible to determine the concentration and rate of elimination in practically all organs and tissues. Measurements were carried out first after prolonged infusion of the contrast under conditions of balanced flow, and secondly six hours after the end of the infusion. It was therefore possible to determine the inflow and loss of contrast medium in various organs or organ systems. The most commonly used angiographic contrast media in Germany were investigated. Their kinetic behaviour is largely identical, their pattern of distribution and elimination depended principally on the organ or tissue. In another study injections were carried out through angiographic catheters in a "physiological angiographic" manner. Measurements obtained show that distribution and excretion of the contrast medium are independent of the site of injection. The kinetics of the contrast within an organ do not differ, whether it is injected selectively or not. The presence of an entero-hepatic circulation of angiographic contrast media has been demonstrated, but quantitatively it is of little importance.