Experimental trypsin-induced urothelial cell separation in vivo.

A morphological study of the effects of different concentrations of trypsin on the normal rat bladder in vivo is described. A low concentration (5000 u/ml) of the pure enzyme caused extensive urothelial cell separation following intravesical instillation via a catheter for 30 min. Urothelial regeneration commenced within 12 h and the appearance of the bladder was normal within 3 months. However, the development of submucosal haemorrhage and ulceration, partly as a result of infection, indicates that further experimental work is required before trypsin can be evaluated clinically for removing in situ carcinoma or reducing tumour bulk. The enzyme might also be used to produce more cellular material for cytological examination.