[Some parameters of Guerin cancer growth after exposure to Pielik (sodium salt of 2,4-dichlorophenoxyacetate)].

Herbicide Pielik (sodium 2,4-dichlorophenoxyacetate) was tested with the aid of Guerin cancer animal model in 129 Wistar rats. An effect of this herbicide on the cancer growth dynamic (size and weight of the tumor), its malignancy (lymphatic nodes involvement), tumor-dependent animal cachexia (real body weight), and survival of rats depending on exposure period have been analysed. Aqueous solution of the herbicide was administered to animals of groups II, IV, V, and VI in the dose of 200 mg/kg body weight daily (1/3 LD50). Young rats were exposed to the herbicide during pre- and postnatal period till the death (groups III, IV and VI in the 80th day of life. Exposure to the herbicide was continued. Rats of all groups were sacrificed in the 16th, 20th, and 42nd day after implantation of Guerin cancer. Eight animals of each group were kept alive to assess survival. Accelerated growth of the tumor was noted in the animals exposed to the herbicide for the prolonged period of time (before and after birth). The same daily dose administered to the animals after weaning and continued to the 16th, 20th, and 42nd day of tumor development (group IV) has not significant effect on tumor growth rate. An increase in the incidence as well as earlier onset of metastases to auxillary and groin lymphatic nodes were seen in group VI in comparison with the control animals (group III).