RESUMO
Nucleic acids [DNA and RNA] were determined in spleen tissues of four groups of rats: control [normal diet] rat, rat fed on 70% normal diet + 30% soybean, rat fed on normal diet but supplied with drinking water contains nitrosamine, and rat fed on 70% normal diet + 30% soybean and drinking water.contains nitrosamine. The experimental period was 9 months, but the treatment with nitrosamine was for 6 months. Nitrosamine tends to increase RNA amounts after 3 months and increases DNA amount after the same period. The activity of endonuclease, nuclease, RNase A and RNase T1 was increased after 3 months as a result of the stress factor, but after 9 months, all the activities were inhibited in addition to the activities of DNase I. The treatment with nitrosamine for 9 months inhibited the nucleic acid formation. Total proteins in the tissue were reduced as a result of nutrosamine treatment