Spontaneous porphyria of the Long-Evans Cinnamon rat: An animal model of Wilson's disease

To confirm and extend our previous microspectrophotometric observations of 30-week-old male Long-Evans Cinnamon (LEC) rats, an animal model of human W ilson's disease, we analyzed the porphyrin patterns of the organs, urine, a nd plasma of LEC rats. Abnormal accumulation of porphyrins, especially high ly carboxylated porphyrins (uro- and heptaporphyrin), in the kidneys and li ver was seen in male and female LEC rats aged 30 weeks and also in 10-week- old rats, before the onset of spontaneous hepatic dysfunction, Accumulation of copper and iron in the kidneys was not observed in the 10-week-old rats . Massive accumulation of porphyrins was observed only in the kidneys of th e 30-week-old male LEC rat, indicating that this symptom is related to sex and age. Renal accumulation of porphyrins was reflected in the rate Of urin ary porphyrin excretion. Hepatic accumulation of porphyrins appeared to be independent of sex and age. These results indicate that neither renal nor h epatic porphyrin accumulation is the result of renal deposition of metals o r of spontaneous hepatic dysfunction and that porphyrinuria in the LEC rat is closely related to the renal accumulation of porphyrins. In contrast to these organs, a reduction in the porphyrin levels was observed in the brain of the LEC rat, This was independent of sex and age. The present work stre sses the existence of an abnormal heme metabolism in the LEC rat, and thus, the necessity to study the heme metabolism in human Wilson's disease is st rongly suggested. (C) 2000 Academic Press.