[Serum concentration and distribution in the liver, lung, heart and kidney of platinum after hepatic arterial injection in the form of cis-diammine dichloroplatinum microcapsule in rabbits].

After injection into the hepatic artery of New Zealand rabbits of microencapsulated CDDP (CDDPmc,group A) and non-encapsulated CDDP (group B), the platinum concentrations in sera and in the liver, lung, heart and renal tissues were determined and the hepatic and renal function monitored at various time intervals. The serum platinum concentration in group A increased slowly following administration of CDDPmc and gradually decreased after reaching its highest level. In contrast, it reached the maximum level immediately after the injection of CDDP and then decreased rapidly in group B, with the peak concentration being 4.5 times as high as that in group A. The hepatic tissues maintained a high level of the platinum for at least 21 days after the injection in group A, but for only a short period of time in group B. The platinum level was found to be low in the lung and heart tissues and high in the renal tissues in both groups, with the renal concentration being much higher in group B than in group A. The animals of both groups suffered some extent of hepatic and renal disfunction, but again, it was much more severe for animals in group B. The above results demonstrated that drug concentration in target tissues could be kept at a higher level, and in circulating blood at a lower level by the microcapsule technique than by the conventional administration technique, raising hopes that the therapeutic effect might be enhanced and the general side effects of CDDP reduced.