The source of urinary epidermal growth factor in XXXX .

@entity1 @entity908 @entity1098 @entity1011
To clarify the source of @entity1 urine EGF, we studied EGF renal clearance in 20 healthy, young adult subjects. Immunoreactive EGF was measured hourly in @entity1098 plasma, heparin plasma, serum and urine of 12 males and 8 females during a 3 h study period. Plasma and urine @entity1011 and @entity1011 clearance were measured and calculated hourly. Mean (and SEM) @entity1011 clearance was similar in males and females (118 +/- 12 vs 105 +/- 6 ml/min). EGF was not detectable in plasma, whereas relatively high levels were measured in serum (2.5 +/- 0.25 vs 1.5 +/- 0.18 ng/ml in males and females respectively p less than 0.05). Urine EGF excretion averaged 1641 +/- 233 ng/h in males and 1507 +/- 191 ng/h in females (p greater than 0.05). A significant correlation was observed between urine @entity1011 and urine EGF concentrations in both male (r = 0.98, p less than 0.01) and female (r = 0.94, p less than 0.01) subjects. EGF immunoreactivity in urine and serum eluted from G-75 sephadex columns similarly to recombinant 6000 Mr hEGF. Urine excretion of EGF approximated 1.5 micrograms/h or 25 ng/mg @entity908 . The high concentrations of EGF found in urine in the face of non-detectable levels of EGF in plasma favor the hypothesis that EGF in urine is derived from kidney synthesis and secretion. The significant positive correlation between urine @entity1011 and urine EGF suggests a functional correlation between glomerular filtration and the process of tubular EGF excretion.
