CHRONIC TREATMENT WITH EPIDERMAL GROWTH-FACTOR STIMULATES GROWTH OF THE URINARY-TRACT IN THE RAT

Twenty-four male Wistar rats, 8 weeks old, were allocated into three g roups and treated with human recombinant epidermal growth factor (EGF) administered subcutaneously in doses of 0, 30, and 150 mu g/kg per da y for 4 weeks, Blood sampling was done every 2nd week and urine sampli ng was done for 2 consecutive days every week. The most striking findi ng was that the ureters were dose dependently enlarged, due to growth of all layers of the ureteric wall. The urothelium of the bladder show ed considerable hyperplasticity with a widening of the basal prolifera tive compartment and a normal differentiation pattern as observed by t he expression of carbohydrate epitopes, characterized with lectinohist ochemistry. Blood examination revealed a decrease in blood haemoglobin concentration and a slight increase in serum creatinine concentration in the high-dose group. There were no effects of EGF on the urinary e xcretion of electrolytes, proteins, and endogenous EGF.