Biphasic development of pentagastrin sensitivity in rat stomach

Area of Science:

• Developmental Biology
• Gastroenterology
• Physiology

Background:

• Gastric acid secretion is vital for digestion and protection.
• Pentagastrin is a key stimulant of gastric acid production.
• Understanding the developmental timeline of gastric function is important.

Purpose of the Study:

• To investigate the development of rat stomach sensitivity to pentagastrin.
• To determine the onset and disappearance of pentagastrin-stimulated acid secretion.
• To correlate pentagastrin sensitivity with serum gastrin levels and gastric permeability.

Main Methods:

• In vivo and in vitro studies on fetal (days 19-21) and newborn (5-day-old) rat stomach preparations.
• Gastric acidification measured by pH in vivo and H+ fluxes in vitro using an Ussing chamber.
• Quantification of fetal serum immunoreactive gastrin levels.

Main Results:

• Rat stomach first responded to pentagastrin on day 20 of gestation.
• Dose-dependent H+ secretion observed in vitro between 10(-8) and 10(-6) M pentagastrin.
• Pentagastrin sensitivity diminished significantly in 5-day-old pups.
• Immunoreactive gastrin was present from day 16, but stimulation occurred later.

Conclusions:

• Rat stomach acid secretion becomes sensitive to pentagastrin around day 20, coinciding with decreased permeability.
• Pentagastrin sensitivity is transient, disappearing in early postnatal life.
• The development of pentagastrin sensitivity in the rat stomach is a biphasic process.