Host: The Japanese Society of Toxicology
Butachlor and Alachlor, chloroacetanilide herbicides, induce glandular stomach tumors in rats. We re-evaluated the pathogenesis and human relevance of the tumors. From the re-evaluation of stomach sections stained with neuron-specific enolase and chromogranin A, all tumors were derived from ECL cells. The tumor formation involved a nongenotoxic threshold MOA initially characterized by mucosal atrophy, leading to hypochlorhydria and hypergastrinemia. The mucosal atrophy with hypergastrinemia stimulated the ECL cell proliferation, resulting in neoplasia. We concluded the tumors developed via a threshold-dependent nongenotoxic MOA, under conditions not relevant to humans.
