Obesity Induced in Mice Injected Intracerebrally with 4-Nitroquinoline 1-Oxide or 4-Hydroxyaminoquinoline 1-Oxide 1

Summary

Obesity was induced in 45 and 36% of mice by intracerebral injection with the carcinogens 4-nitroquinoline 1-oxide (NQO) and 4-hydroxyaminoquinoline 1-oxide (HAQO), respectively, but not with the related noncarcinogens, 4-aminoquinoline 1-oxide, 3-methyl-4-nitroquinoline 1-oxide, and 4-nitropyridine 1-oxide. Food and water intake were markedly increased in the obese mice. While dietary restriction decreased the body weight, release of the restriction caused a conspicuous increase of food intake followed by a gain in body weight. No obesity could be induced with the following 4 local carcinogens: 3, 4-benzpyrene, β-propiolactone, N-ni-trosomethylurea and N-hydroxy-N-2-fluorenylactamide.

The authors thank Mr. T. Yamamoto and Mr. K. Ohno for their technical assistance. We are indebted to Dr. A. Ohta, this institute, Dr. Y. Kawazoe, National Cancer Center Research Institute, and Drs. John and Elizabeth Weisburger, National Cancer Institute, U. S. A., for their generous supply of the carcinogens and related compounds. We are also grateful to Professor Emeritus E. Ochiai, Tokyo University, and Dr. W. Nakahara, National Cancer Center Research Institute, for their interest and encouragement.