Acinar cell responsiveness to urecholine in the rat pancreas during fetal and early postnatal growth

Area of Science:

• Gastroenterology
• Developmental Biology
• Pharmacology

Background:

• Pancreatic acinar cells are crucial for digestion, secreting enzymes like amylase, lipase, and chymotrypsin.
• Cholinergic stimulation plays a role in regulating pancreatic exocrine secretion.
• Understanding the developmental timeline of this response is key to pediatric gastroenterology.

Purpose of the Study:

• To determine the developmental stage at which rat pancreatic acinar cells acquire cholinergic responsiveness.
• To characterize the ontogeny of enzyme release in response to cholinergic agonists during fetal and postnatal life.

Main Methods:

• In vitro measurement of amylase, lipase, and chymotrypsin release from rat pancreas.
• Stimulation with urecholine (a cholinergic drug) at various postnatal ages.
• Comparison of responses in fetal, newborn, and juvenile rats to adult controls.

Main Results:

• Fetal and newborn rat pancreas showed no response to urecholine.
• A detectable response emerged by day 3 of postnatal life.
• Pancreatic sensitivity to urecholine increased progressively from day 3, with peak responsiveness observed between days 15 and 21.

Conclusions:

• Rat exocrine pancreas acquires responsiveness to cholinergic stimulation around the 3rd day of postnatal life.
• The sensitivity to cholinergic drugs increases significantly during the first three weeks after birth.
• These findings highlight a critical window for the development of pancreatic secretory function.