EXPERIMENTAL STUDIES ON JAPANESE B ENCEPHALITIS WITH THE RADIOACTIVE P³²

2. INVESTIGATION OF NUCLEIC ACID METABOLISM BY STHMIDT AND THANNHAUSER'S METHOD IN THE ORGANS, BRAIN AND LIVER, OF MICE INOCULATED INTRAPERITONEALLY WITH JAPANESE B ENCEPHALITIS VIRUS

Abstract

Nucleic acid metabolism in brain and liver of mice inoculated intraperitoneally with Japanese B Encephalitis Virus was investigated by Schmidt and Thannhauser's method. P³² was used chiefly as the tracer throughout this investigation.
P³² was intraperitoneally injected 66 and 138 hours after the mice were inoculated with the virus.
After 6 hours, certain quantities of brain and liver were collected to be fractionated by Schmidt and Thannhauser's method into DNA- and RNA-fractions.
The P³² activity and quantities of these nucleic acid fractions were investigated in this experiment.
As the control objects, the healthy mice injected intraperitoneallywith P³² were used.
In the incubation period, an increase of the P³² activity in liver was recognized both in the DNA- and the RNA-fractions, especially in the latter.
This fact shows that, the nucleic acid metabolism of the liver suffers a marked change in the incubation period.
On the other hand, at the acme stage of infection, an increase of the P³² activity was observed in the DNA fraction of the brain. And then, quantitatively, during the incubation period, a marked change was not seen in the DNA-P and the RNA-P, but at the acme stage of infection, both the DNA-P and the RNA-P increased; while no increase was observed in the fraction of control objects.
It is quite interesting that the results of this investigation was the same as those of investigation made by the mice inoculated intracerebrally with Japanese B Encephalitis Virus.