Radiological detection and sequential observation of experimentally induced bladder tumours in the European hamster.

FOUR GROUPS OF EUROPEAN HAMSTERS (STRAIN MHH: EPH) were treated subcutaneously once weekly for life with 1/20 or 1/40 the LD(50) of DBN while another 2 groups served as controls. Three animals of each group were x-rayed every 2 weeks after i.v. injection of the contrast agent Urographin. By means of cystograms tumours of the urinary bladder were detected between the 20th and 26th weeks after beginning treatment when they had reached a diameter of 1-2 mm; their development was subsequently observed by periodical x-ray examinations. The technique described is simple and provides a valuable means for obtaining additional in vivo information concerning latency period, growth rate and identity of experimentally induced primary urinary bladder tumours in the European hamster.