Subchronic toxicity of chlorpropham (CIPC) in ICR mice

Male and female ICR mice were given 0, 1875, 7500 or 30,000 ppm of chlorpropham (CIPC) in the diet for 13 weeks. Methemoglobin levels of male and female mice in the 7500 and 30,000 ppm groups were significantly elevated. Hemoglobin concentration, packed cell volume, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and white blood cell count of male and female mice in the 30,000 ppm group were significantly increased. Dose-dependent splenomegaly was observed in male and female mice in the 7500 and 30,000 ppm group. Congestion, increased hemosiderin deposition and increased extramedullary hematopoiesis in the spleen, hematopoietic cell hyperplasia and hemosiderin deposition in bone marrow was observed dose dependently in male and female mice in the 7500 or 30,000 ppm group. Eosinophilic granular cytoplasm of hepatocytes, sinusoidal dilatation, hemosiderin deposition, extramedullary hematopoiesis and necrosis of hepatocytes were observed in the liver of male and female mice in the 30,000 ppm group. Hemosiderin deposition was increased in the kidney of male and female mice in the 30,000 ppm group. Administration of CIPC in diet for 13 weeks caused methemoglobinemia and splenomegaly in ICR mice.