Fasting and postprandial serum gastrin in neonatal swine, and changes following antrectomy

Postprandial serum gastrin concentrations in normal foals

Postprandial gastrin concentrations were assayed in serum samples from a group of six foals at one day, one week, one month and three months of age. Before sampling, each foal was prevented from feeding for 2 h and was then allowed to suck for 15 mins. Blood samples were taken at the start of the meal and at 30 min intervals for the next 3 h. Feeding increased serum gastrin concentrations at one day, one week and one month, with the greatest increases detected at one day. Mean pre-feeding gastrin concentrations were 25.2 +/- 2.3 pg/ml at one day, 22.8 +/- 3.9 pg/ml at one week, 15.2 +/- 2.3 pg/ml at one month and 15.6 +/- 7.5 pg/ml at three months. Highest mean post prandial concentrations were at 60 mins on Day one (47.4 +/- 15.2 pg/ml) and one month (25.2 +/- 4.1 pg/ml) old foals. There was no apparent post prandial increase in serum gastrin concentrations in foals at three months of age. Precise reasons for changes in postprandial serum gastrin concentrations remain unknown. Factors that could be important include maturation of G cell function, alterations in gastrin metabolism and excretion, and changes in gastrointestinal motility with increasing age.

The effect of antral acidification on serum gastrin levels in neonatal pigs

The cause of the physiologic hypochlorhydria and hypergastrinemia of the newborn is not understood. The effect of antral acidification on basal serum gastrin was studied in 32 anesthetized Landrace piglets divided into four groups of eight animals each: Group A, 1 to 7 days old; Group B, 8 to 15 days old; Group C, 16 to 24 days old; and Group D, 25 to 48 days old. After a 2-hr fast, halothane anesthesia was administered. Inflow and outflow cannulae were inserted into the gastric lumen to create an intact isolated gastric antrum. HCl in saline (pH 2.5) was infused (10 cc/min) for 15 min and drained by continuous suction. The effluent was confirmed to be pH 2.5. Portal venous blood samples were obtained at basal levels and at 5, 10, and 15 min and assayed for gastrin. All groups had markedly elevated serum gastrin levels, as compared to normal adult values, in the basal state. Basal gastrin levels declined with increasing age to approach adult values by 7 weeks. Following antral acidification in Groups A, B, and C, there was a significant reduction in serum gastrin. All suppressed values remained significantly higher than adult basal, however. There was no significant change in gastrin levels in Group D with acidification.(ABSTRACT TRUNCATED AT 250 WORDS)

Physiology of serum gastrin production in neonates and infants

Conflicting data exist regarding the physiology of serum gastrin production in neonates and infants, and the response of the neonatal gastric antrum to feeding. Normal neonates and infants underwent serial determination of fasting and postprandial serum gastrin levels from birth to 4 months of age. The mean fasting serum gastrin levels in newborns and infants up to 4 months remained considerably higher than the mean maternal levels, the elevations being statistically significant until 2 months of age. In addition, in the first 2 months of life, there was no evidence of postprandial stimulation of serum gastrin levels 30 minutes following normal feeds consisting of breast milk or commercial formula. At 3 and 4 months of age, the response appears to revert to an adult pattern with statistically significant postprandial elevations following normal feeds (p = 0.003 and p = 0.02, respectively). This study confirms the presence of neonatal hypergastrinemia and reveals a persistence of elevated serum gastrin levels through early infancy. A maturation of the antral gastrin release response with postprandial elevations of serum gastrin levels occurs at approximately 3 months of age.