Postnatal development of transport function in the pig intestine

Area of Science:

• Gastroenterology
• Neonatal Physiology
• Intestinal Biology

Background:

• Enterocyte development and function are critical for nutrient absorption in newborns.
• The neonatal pig intestine undergoes significant functional changes after birth.
• Understanding these changes is crucial for optimizing nutrition and health in young animals.

Purpose of the Study:

• To investigate the developmental changes in nutrient transport in the neonatal piglet small intestine.
• To examine the effects of specific factors like dexamethasone and EGF on intestinal transport.
• To assess the impact of weaning on intestinal absorptive capabilities.

Main Methods:

• Utilized newborn piglet models to study intestinal enterocyte function.
• Assessed the transport of various nutrients including protein, sodium, glucose, and amino acids.
• Administered dexamethasone and Epidermal Growth Factor (EGF) to evaluate their impact on intestinal functions.
• Analyzed enzyme activities such as sucrase and maltase.

Main Results:

• Prenatally produced enterocytes are primarily responsible for significant protein absorption in newborn pigs.
• A marked decline in the transport of sodium, lysine, lysine-containing dipeptides, and glucose occurs within the first week postnatally.
• Dexamethasone administration doubled the sodium-dependent alanine uptake.
• Postnatal EGF treatment (days 3-6) enhanced sucrase and maltase activity in the distal small intestine.
• Weaning-associated issues do not appear to stem from direct inhibition of intestinal transport properties.

Conclusions:

• Neonatal pig intestinal development involves a rapid decline in nutrient transport capacity after birth.
• Hormonal and growth factor interventions can modulate specific nutrient transport pathways and enzyme activities.
• The findings suggest that weaning problems are unlikely to be caused by a direct impairment of the intestine's transport mechanisms.