Neonatal gastric motility in dogs: maturation and response to pentagastrin.

Postnatal changes in the pH of gastric secretions, gastric motility, serum gastrin concentration, and response of the stomach to pentagastrin administration were studied in 15 beagle puppies from birth to 5 wk of age. Motility was monitored manometrically via twin-lumen catheters 3--6 h postprandially. Mean gastric pH was stable at 5.85 until the 7th postnatal day when pH decreased to 3.45; pH then increased to a mean value of 4.95 through the 18th day. Antral contractions increased from 0.2 contractions per min on the day of birth to a maximum 2.3 contractions per min on the 11th day and then gradually declined. Pentagastrin (8.0 microgram/kg sc) had no effect on gastric pH or motility until the 2nd postnatal wk. Pentagastrin inhibited the rate and peak pressure of antral contractions from the 2nd through the 5th wk. Mean serum gastrin concentrations in six puppies were greater than values for adult dogs, attaining a preweaning maximum on the 9th day.