STUDIES ON THE METABOLIC ACTIVITIES OF THE BLADDER TUMORS

I. STUDIES ON THE NUCLEIC ACID METABOLISM OF THE BLADDER TUMORS

Abstract

Nucleic acid metabolism was studied to observe the metabolic activities of bladder tumors. Surgically obtained specimens were subjected to this study. Radio-active nucleic acid precursors; C¹⁴-formate, which was incorporated into nucleic acids via de novo synthetic pathway, and C¹⁴-8-adenine, which was also incorporated via salvage pathway, were used. These radio-active substances were incorporated into nucleic acids, so that the incorporation rates were expressed as relative specific activities. The results were as follows:
1. C¹⁴-formate incorporation was higher in grade 2, 3, and 4 of bladder tumors than in the control. Also it was highest in stage B2 bladder tumors. Among the purine bases RSA of thymine was the highest. There were no great differences between the other purines and pyrimidines.
2. C¹⁴-8-adenine was also incorporated into nucleic acid bases of the bladder tumors. It was assumed that the higher the grades and stages, the higher the incorporation rates. It was considered that in bladder tumors there was salvage pathway, which had not been described in the literatures.
3. Comparison between de novo synthesis and salvage pathway; Concerning the incorporation rates, salvage pathway was more active than de novo synthesis in bladder tumors.