Gastrin concentration in plasma of the neonate at birth and after the first feeding.

Plasma gastrin was determined simultaneously in 19 newborn infants and their respective mothers shortly after birth and in ten neonates before and after the first feeding. The gastrin concentrations in the umbilical vein plasma of the newborn infants were significantly higher than in the peripheral vein plasma of their mothers. The values were statistically not different from those obtained in the neonates before the first feeding. There was an increase in gastrin concentrations after the first feeding. From these results it is suggested that gastrin is produced in the neonate independently from the mother. It is already secreted after the first feeding. Experiments in rats showed that 125I-gastrin is not transported through the placenta. From these findings we assume that most likely the gastrin measured in plasma of newborn infants is of neonatal origin.