Short-term toxicity study of 4-dimethylaminoazobenzene in marmosets.

The marmoset, a small non-human primate, has rarely been used in toxicological studies. A short-term toxicity study was performed on common marmosets (BW = 330 +/- 32 g). Fifteen male marmosets received oral administration of DAB at a dose level of 56 mg/kg/day and 4 control animals received corn oil alone for a period of 15 days. Hematological, biochemical, histopathological and bone marrow examinations were carried out on the 5th, 10th and 15th day of treatment. Body weight decreased continuously and two animals died on day 10. Decreases in RBC, Hb and Ht and increases in MCV and WBC were observed. Uric acid and glucose were increased and AlP and LAP were decreased. Aldolase, GOT and GPT were increased by day 10, and thereafter recovery of aldolase to the control level and decreases of GOT and GPT were observed. Relative organ weights of the liver, kidney, spleen and adrenal were increased. Histologically, C-cell hyperplasia of the thyroid and slight changes of the liver were noted. Marrow total cell counts were not changed, but the G/E ratio was reduced. Thus, macrocytic anemia, an increase of marrow erythroblasts due to anemia and changes of biochemical parameters indicating liver injury were observed in marmosets; these findings were similar to those in rats in the previous experiments.