This study was performed for assessing carcinogenicity of Folpet using medium-term carcinogenicity bioassay.
Sprague-Dawley rats aged six weeks divided into four grout´s and were initially given an intraperitoneal injection of diethylnirosamine at 200㎎/㎏ body weight.
Two weeks later, group 1(negative control) was treated with basal diet. A Folpet was given per oral administration to group 2(100 ppm) and goup 3(1,000 ppm).
Group 4 was fed on water containing 0.05% phenobarbital sodium as a promtor for six weeks. At three weeks after beginning of the experiment, partial hepatectomy was performed in all rats.
The tumor-promoting effects were examined by the numbers and areas per ㎠ of induced glutatlaion S-tranferase placetal form(GST-P) positive foci in liver, and silver stained nucleolar organizer regions(AgNORs) which have recently introduced as one of the indicators for the cell proliferative activity.
As the results, Folpet didn´t have tumor-promoting effects on GST-P positive foci developement and AgNORs during promoting stage after initiation, whereas phenobarbital sodium treatment group showed promoting effect.
It was concluded that Folpet didn´t have promoting effect at 500, 1,000 ppm using this midium-term carcinogenicity bioassay model.
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