FERRITIN ACCUMULATION AND UROPORPHYRIN CRYSTAL-FORMATION IN HEPATOCYTES OF C57BL 10 MICE - A TIME-COURSE STUDY/

To establish the time-sequence relationship between ferritin accumulat ion and uroporphyrin crystal formation in livers of C57BL/10 mice, a b iochemical, morphological and morphometrical study was performed. Urop orphyria was induced by the intraperitoneal administration of hexachlo robenzene plus iron dextran and of iron dextran alone. Uroporphyrin cr ystal formation started in hepatocytes of mice treated with hexachloro benzene plus iron dextran at 2 weeks and in mice treated with iron dex tran alone at 9 weeks. In the course of time, uroporphyrin crystals gr adually increased in size. Uroporphyrin crystals were initially formed in hepatocytes in the periportal areas of the liver, in which also fe rric iron staining was first detected. The amount and the distribution of the main storage form of iron in hepatocytes, ferritin, did not di ffer between the two treatment groups. Ferritin accumulation preceded the formation of uroporphyrin crystals in hepatocytes in both treatmen t groups. Moreover, uroporphyrin crystals were nearly always found clo se to ferritin iron. We conclude that uroporphyrin crystals are only f ormed in hepatocytes in which also iron (ferritin) accumulates. Hexach lorobenzene accelerates the effects of iron in porphyrin metabolism, b ut does not influence the accumulation of iron into the liver.