Gastrin 17 and Gastrin 34, Before and After a Meal, in Newborn Infants

Summary In 89 healthy full‐term newborn infants, we studied the different contribution of gastrin 17 (G17) and gastrin 34 (G34) to neonatal hypergastrinemia and the G17 and G34 response to a meal in the first days of life. Serum concentrations of G17 and G34 were measured by radioimmunoassay specific for the NH2‐terminus of G17 and G34 in 23 newborn infants in the cord blood and in 66 newborn infants before or 20 min after bottle‐feeding. Basal serum G17 and G34 values were also obtained in 38 healthy fasting adults. Mean (±SEM) G17 levels in the cord blood were not different from those of the adult controls (29.28 ± 4.16 versus 31.00 ± 2.62 pg/ml) and increased significantly either at 12 h (48.06 ± 7.32 pg/ml, p < 0.025) or on the 4th day of life (80.56 ± 9.99 pg/ml, p < 0.01). Serum G34 levels in the cord blood were significantly higher than in adult controls (163.22 ± 11.19 versus 126.68 ± 5.57 pg/ml, p < 0.005) and increased at 12 h of life (225.22 ± 25.95 pg/ml, p < 0.02), but no increase was found on the 4th day of life (204.87 ± 18.08 pg/ml). Neither postprandial G17 nor G34 increases were found on the 1st or on the 4th day of postnatal life. The study supports the following conclusions: (a) neonatal hypergastrinemia is mainly due to G34 fraction; (b) the increased levels of gastrin on the 4th day of life are due to G17 fraction; (c) bottle‐feeding does not stimulate either G17 or G34 release in the first 4 days of life.