Drug-induced porphyrin biosynthesis—II simple procedure for screening drugs for porphyria-inducing activity

A series of drugs has been tested for porphyria-inducing activity in the intact chick embryo and in mice and the results compared with those previously obtained in chick embryo liver cells grown on cover slips. The results obtained in the intact chick embryo corresponded in the majority of cases with results obtained with the isolated liver cells. For this reason the intact chick embryo may be used as a rapid and simple procedure for screening drugs for porphyria-inducing activity. Although many of the drugs which induced porphyrin accumulation in the chick embryo liver appear to be inactive in mouse liver, evidence is presented that the results obtained with chickembryo liver allow better prediction of results to be expected in porphyric patients than the results in mouse liver.