[Uptake and distribution of epidermal growth factor in certain organs of the dog]

Epidermal growth factor (EGF) besides salivary glands and saliva has been lately detected in kidney and urine. The liver was previously considered as the most important place of this peptide's metabolism. A little was known about other places of EGF degradation. In our studies which were performed on anesthetized dogs EGF was administered by intravenous infusion to compare the different places of its degradation. Plasma EGF level was measured in blood samples taken from femoral artery and from cervical, femoral, renal, portal and hepatic vein. Basal plasma EGF level was 8 +/- 2 pg/ml. During exogenous infusion of hEGF in dose of 0.25 and 1.0 micrograms/kg/h arterial plasma levels were increased to 622 +/- 128 pg/ml and 1441 +/- 294 pg/ml respectively. After blood passage by the brain, lower leg, small bowel and liver percent of decrease in plasma EGF level was about 30-40%. In comparison to arterial value, the renal venous plasma level was decreased significantly by about 95%. Amount of EGF detected in urine during i.v. infusion decreased approximately by 30%. Mean half life of EGF was 2.32 +/- 0.5 min. Our study strongly suggests that EGF detected in urine is mostly cleared out by kidneys.