Induction de tumeurs mammaires par injections d'extraits acellulaires de leucémies PS à des souriceaux d'autres souches

Abstract

Cell free extracts from 10 leukaemias and 2 passages of leukaemic isografts PS were obtained following Gross's or Moloney's technique. Some of them were submitted to ultracentrifugation on preformed density gradients of potassium citrate. Cell free extracts and the zones collected after untralcentrifugation were injected into new-born and weanling mice of different strains: 101 BALB c , C3 H eB , Swiss and PS mice survived 9 months. The occurrence of mammary tumours was the prominent feature of this study: 62,5 per cent of the BALB c , 66% of the C3 H eB , 23% of the Swiss developed mammary tumours. In the PS strain, the mean age of mammary tumours' development fell from 10,3 months in the controls to 6,4 months in the inoculated mice. These results are discussed. So is the action of polyoma virus and the blood-borne activity of mammary tumour agent. These results are compared with those obtained with other strains of mice carrying both a mammary tumour agent and a leukaemia virus.