Abstract

In an attempt to elucidate the pathological effects of phenol, the present study was undertaken in male Sprague-Dawley rats. The control group of animals was fed a basal diet, and potable underground water. The experimental group of animals was fed a basal diet and potable underground water containing 30ppm, 60ppm, and 1% phenol with once a week administration of dimethylnitrosamine(DMN) 10 mg/kg I.P. Each group of animals was sacrificed on the 3rd, 6th, and 9th month. The liver and gastrointestinal tract were examined light microscopically, along with transmission electron microscopic studies of the liver and scanning electron microscopic studies of the gastric mucosa. The results were as follows: 1) In the acute phenol intoxicated group, the liver showed fatty changes in the hepatocytes with mitochondrial membrane destruction and myelin figure formation. 2) In the chronic phenol intoxicated group, fatty changes in the liver were observed. In addition, there was chronic inflammation in the gastrointestinal tract, with gastric mucosal erosion and central necrosis of the hepatic lobules, especially in the high phenol contaminated water treated group. 3) As a result of the examination under the light microscope, the DMN treated group showed hyperplastic nodules and liver cell dysplasia, the degree of which was proportional to the duration of the experiment, and was more severe in the DMN + phenol treated group. 4) As a result of the examination under the electron microscope, fatty changes in the liver, pleomorphism of the mitochondria and loss or shortness of bile canalicular microvilli in the DMN + phenol treated group were more severe than in the group treated only with DMN. In summary, the results obtained by the present study indicate chronic highly concentrated phenol intoxication induce liver cell necrosis and chronic inflammatory with a hepatotoxin such as DMN.

• Keywords: Phenol toxicity;Dimethylnitrosamine;Liver;Gastrointestine