The carcinogenicity of polycyclic hydrocarbon epoxides in newborn mice.

P L Grover,B C Mitchley,F J Roe,P Sims

doi:10.1038/bjc.1975.24

Abstract

Benz(a)anthracene injected subcutaneously during the first 3 days of life caused a dose related increase in the incidence of liver and lung tumours in Swiss mice but over a similar dose range, the K region epoxide of benz(a)anthracene was less effective. Neonatally injected 7-methylbenz(a) was considerably more active than its K region epoxide in increasing the incidence of liver tumours in males. Both the parent compound and the epoxide slightly raised the incidence of lung tumours. Both chrysene and its K region epoxide increased liver tumour incidence but not lung tumour incidence. The K region epoxides of dibenz(a,h)-anthracene and 3-methylcholanthrene were without apparent effect on the incidence of liver, lung or other tumours despite indications from previously reported studies that the parent hydrocarbons are active at the same dose levels. The K region epoxide of phenanthrene had no effect on the incidence of any kind of neoplasm.

Highlights

Summary.-Benz(a)anthracene injected subcutaneously during the first 3 days of life caused a dose related increase in the incidence of liver and lung tumours in
In all groups treated with benz(a)anthracene the incidence of both lung and liver tumours was higher than in mice exposed to the vehicle, polyethylene glycol (PEG) 400, only (Group G)
K region epoxides derived from polycyclic hydrocarbons has been tested in newborn mice partly because of the conflicting results that have previously been obtained from tests in adult animals and from in vitro malignant transformation systems

Summary

Introduction

Summary.-Benz(a)anthracene injected subcutaneously during the first 3 days of life caused a dose related increase in the incidence of liver and lung tumours in. Injected 7-methylbenz(a)anthracene was considerably more active than its K region epoxide in increasing the incidence of liver tumours in males. Both the parent compound and the epoxide slightly raised the incidence of lung tumours. The K region epoxides of dibenz(a,h) anthracene and 3-methylcholanthrene were without apparent effect on the incidence of liver, lung or other tumours despite indications from previously reported studies that the parent hydrocarbons are active at the same dose levels. We have tested the K region epoxides derived from phenanthrene, benz(a)anthracene, 7-methylbenz(a)anthracene, dibenz(a,h)anthracene, chrysene and 3-methylcholanthrene, together with some of the CARCINOGENICITY OF POLYCYCLIC HYDROCARBON EPOXIDES IN MICE parent hydrocarbons, for carcinogenicity using newborn mice. This paper presents the results that were obtained in these experiments

Methods

Results

Conclusion