Maturational changes and origin of urinary human epidermal growth factor in the neonatal period

In order to clarify the characteristics of urinary human epidermal growth factor (hEGF) excretion in the newborn period, we examined hEGF in the 41 newborn infants; 12 healthy preterm infants (group A), 10 healthy full-term infants (group B), 12 full-term infants with neonatal asphyxia (group C), 7 full-term infants treated with tobramycin (group D) during the first week of life. Renal function tests, i.e. creatinine clearance (Ccr), and N-acetyl-beta-D-glucosaminidase (NAG) as a parameter of renal tubular damage, were examined in 29 full-term infants. Urinary hEGF excretion showed a linear increase with gestational age. During the first week of life, urinary hEGF excretion in group B increased with age. However, urinary hEGF excretion in group A remained at the constant level through the study period. Ccr in group C was significantly decreased through the study period when compared with that in group B. NAG indices in group C during the first week of life and those in group D on days 5-7 of life were more elevated than those in group B. Urinary hEGF excretion in group C on days 4-7 of life and that in group D on day 7 of life were significantly decreased when compared with that in group B. These results suggest that urinary hEGF excretion is related to the maturation and that the source of urinary hEGF may be renal tubular cells.