Serial Irradiation of Mouse Tumours: Some Changes in Histology and Cytology

Abstract

THE method of seriaRy irradiating mouse tumours by transplantation into fresh hosts between each irradiation, enables histological changes to be observed divorced from the direct and indirect local effects of irradiation on the tumour bed. Snellman (1935) (Pearson, 1959a). One irradiated hne of sarcoma 37 received tumour sub-lethal doses of 3000 r at each stage (" B " hne) and one received half-lethal doses of 2000 r (" D " line). Tumour sub-lethal doses were administered at each stage to the homologous spindle-ceRed sarcoma BPI (" F " line) and mammary adenocarcinoma MV212 (" G " line). Tumour material for histological study was obtained from transplanted post-irradiation tumours from each irradiation stage and also from untreated sub-hne passages of the 12th stage of the sarcoma 37 cc B " line.The tumour material was treated with Susa fixative for 2 to 3 hours and embedded in paraffin wax by chloroform substitution from alcohol. Sections were cut at 6 # and stained in haematoxylin and eosin. RESULTSNo marked histological differences were apparent between tumou-rs of the spindle-ceRed sarcoma BPI (Fig. 2 and 3) and adenocarcinoma MV212 and their respective irradiated hnes cc F " and " G ". Small regions in c' G " line tumours