[In vitro and in vivo studies of RNAse of Bacillus intermedius]

Cytotoxicity of RNAase from Bacillus intermedius was studied in vitro and in vivo. It was shown that the enzyme had slightly pronounced cytotoxicity according to the tests with inhibition of cell proliferation and biosynthesis of cell nucleic acids. The RNAase was also shown to impair the vital staining by neutral red. The efficiency of the impairment much more depended on the enzyme catalytic activity than on the proliferation and biosynthesis of nucleic acids. In vivo toxicity of RNAase from B. intermedius was 3-5 times higher than that of pancreatic RNAase. Possible mechanisms of the different toxicity of the enzymes are discussed.