Ureteric growth in a Goettingen minipig induced by epidermal growth factor. A case report

We have recently discovered that prolonged systemic administration of epidermal growth factor (EGF) induces a remarkable growth of all wall layers of the urinary tract in minipigs. In the present paper, we report the most pronounced changes induced by 4 weeks of systemic EGF challenge in two pigs treated for four weeks with either solvent or EGF (30 micrograms/kg/day), respectively. The EGF treated ureter was longer and thicker with an approximately four fold increase in diameter. All wall layers were enlarged. The urothelium was increased from 5 to 10 cellular rows with basal hyperplasia and an increased number of goblet cells and cells with intracytoplasmic lumina in the luminal half. In the muscular coat, the bundles of hypertrophied cells and intervening connective tissue were enlarged. The present paper suggests a possible in vivo approach to increase the amount of tissue needed in reconstructive surgery of the urinary tract.