Promoting action of glycerol in pulmonary tumorigenesis model using a single administration of 4-nitroquinoline 1-oxide in mice.

Abstract

This study was carried out to clarify the promoting effect of glycerol on 4-nitro-quinoline 1-oxide (4NQO) tumorigenesis in the lung. Animals used were 80 ddY male mice, 6 weeks old. 4NQO, dissolved in olive oil-cholesterol (20:1) mixture, was injected subcutaneously at a dose of 10 mg/kg body weight per mouse. Drinking water contained 5% glycerol. Mice were divided into the following 4 groups of 20 animals each: non-treated mice (group I), mice given glycerol alone (group II), mice given 4NQO alone (group III), mice receiving combined administration of 4NQO and glycerol (group IV). The percent of mice having induced pulmonary tumors and the mean number of tumors per mouse were 2 and 0.10 +/- 0.07 (mean +/- SE), 2 and 0.10 +/- 0.07, 9 and 0.45 +/- 0.25, and 58 and 2.90 +/- 0.62, respectively. A significantly higher rate was seen in group IV, as compared with the 4NQO-treated control. This result showed that glycerol has a promoting action on 4NQO-induced pulmonary tumorigenesis in mice.