Studies on the effect of aurintricarboxylic acid (ATA) on cell proliferation of renewable epithelial tissues in the mouse.

The effect of a three-week treatment regimen with 2, 4 or 6 mg aurintricarboxylic acid (ATA) per kg body weight on the cell proliferation of jejunal crypts and dorsal epidermis of the nude mouse was studied using standard autoradiographic methods after in vivo pulse labelling with 3H-thymidine. ATA was slightly toxic to the animals in a dose-dependent manner (p < 0.01), as measured by the decrease of the rate of weight gain of the treated animals. In the small intestine, ATA led to a shrinkage of crypt length by a factor of 10-15% (p < 0.05), mainly by inhibiting cell proliferation in a dose-dependent manner (p < 0.05) and only secondarily and at higher doses by additionally increasing the cell loss. On the contrary, both the 3H-thymidine labelling index and the mitotic index of the basal cell layer of the epidermis are found to be increased under treatment with ATA. Thus, the present findings indicate that ATA may differentially affect the tissue homeostasis of different renewable epithelia in vivo.