SUPPRESSION OF LIVER ALLOGRAFT-REJECTION BY ADMINISTRATION OF 15-DEOXYSPERGUALIN - COMPARISON OF ADMINISTRATION VIA THE HEPATIC-ARTERY, PORTAL-VEIN, OR SYSTEMIC CIRCULATION

In this experiment, the effect of the administration route - the hepat ic artery, portal vein, or systemic circulation - of the immunosuppres sive drug 15-deoxyspergualin (DSG) on the suppression of liver allogra ft rejection is investigated. A 3-day injection of DSG at a dose of 0. 32-1.28 mg/kg per day into the systemic circulation of a rat that had received a liver transplant was not effective in prolonging liver graf t survival (14.3 +/- 2.9 days vs. 14.1 +/- 2.5 days for controls). How ever, the administration of DSG into the portal vein following liver t ransplantation markedly prolonged survival for up to 24.9 +/- 10.0 day s. Survival times were prolonged even more when the DSG was administer ed via the hepatic artery for 3 successive days after liver grafting ( 30.9 +/- 9.6 days). The concentration of DSG in the blood following th e one-shot injection of DSG was highest when DSG was administered via the hepatic artery, intermediate when injected into the portal vein, a nd lowest when injected into the systemic vein. In conclusion, DSG can inhibit liver graft rejection more effectively via the hepatic arteri al route than via the portal vein or systemic circulation.