A difference between two strains of rats in their liver non-haem iron content and in their response to the porphyrogenic effect of hexachlorobenzene.

Female Agus rats developed hepatic porphyria at a much faster rate than female Porton-Wistar rats when fed a diet containing 0.01% of hexachlorobenzene (HCB). They also showed a greater inhibition of liver uroporphyrinogen decarboxylase [EC 4.1.1.37] activity and a marked stimulation of 5-aminolaevulinate synthetase [EC 2.3.1.37]. The difference between the two strains could not be correlated with differences in the liver concentrations of HCB. However, control Agus rats were found to possess significantly higher levels of total non-haem iron in their livers than the Porton animals. This was particularly apparent after 24 h of starvation and is further evidence for the involvement of iron in the pathogenesis of HCB-induced porphyria. The posterior lobes of the livers from the Agus rats given HCB became porphyric more slowly than the remainder with less severe inhibition of uroporphyrinogen decarboxylase. In contrast to their increased susceptibility to HCB, the Agus rats were less susceptible to another prophyrogenic agent, 3,5-diethoxycarbonyl-1,4-dihydrocollidine.