Urinary excretion of epidermal growth factor and transforming growth factor-alpha in breast-fed and formula-fed infants.
Urinary epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) concentrations were determined by radioimmunoassay in a longitudinal study analyzing 348 24-h urine specimens of 32 infants (16 breast-fed, 16 formula-fed) during the first 16 weeks of life. EGF excretion showed a statistically significant increase from 6.0 +/- 2.5 to 14.1 +/- 4.9 micrograms/g creatinine (mean +/- 1 SD) during the investigation period. TGF-alpha levels were fairly constant throughout this period. Comparing breast-fed infants, with more than 100-fold higher ingestion of EGF and TGF-alpha, with formula-fed infants, no significant differences in urinary EGF and TGF-alpha excretion were observed. These results do not rule out a systemic effect of EGF and TGF-alpha after intestinal absorption in breast-fed infants. The results suggest, however, that urinary EGF and TGF-alpha originate mainly from sources other than intestinal absorption.
Santer
R
R
Department of Pediatrics, Christian-Albrechts-University, Kiel, Germany.
Borlinghaus
P
P
Sievers
E
E
Segura
E
E
Lamerz
R
R
D001903:Bottle Feeding; D001942:Breast Feeding; D004815:Epidermal Growth Factor / Q000652:urine*; D006801:Humans; D007223:Infant; D007225:Infant Food; D007408:Intestinal Absorption; D008137:Longitudinal Studies; D016211:Transforming Growth Factor alpha / Q000652:urine*
D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor