The effect of chlorinated chemicals on porphyrin metabolism--the synergistic effect with chlorinated chemicals and low concentrations of griseofulvin.

: The synergistic effect of chlorinated chemicals and 0.1% griseofulvin on porphyrin metabolism was investigated. Feeds containing 0.1% 4-chloro-m-cresol, 0.1% cumarone or 0.25% trichloroacetic acid with or without 0.1% griseofulvin were given to dd-y strain mice respectively. The treatments were continued for 10 to 450 days, after which coproporphyrin and protoporphyrin in the erythrocytes and liver were analyzed. In the 0.1% griseofulvin alone group, protoporphyria was induced in 6 of 55 dd-y strain mice, although the other 49 mice did not show any abnormal porphyrin metabolism and the severity of the protoporphyria was mild in the 6 mice. In the 4-chloro-m-cresol group, a slight elevation of erythrocytic porphyrins was seen, but the difference was not statistically significant. Elevation of the hepatic porphyrins was not seen. Trichloroacetic acid and cumarone did not influence porphyrin metabolism, and also there was no synergistic effect of griseofulvin on porphyrinopathy. These results suggest that the three chemicals selected in this study are not capable of inducing porphyrinopathy.