Related Experiment Videos
Postprandial hemodynamics and oxygenation in developing piglet intestine.
1Department of Pediatrics, Louisiana State University Medical Center, Shreveport 71130.
The American Journal of Physiology
|June 1, 1991
Summary
Newborn piglets show unique intestinal responses to feeding. While oxygen uptake increases similarly across ages, never-nursed newborns rely solely on oxygen extraction, risking tissue hypoxia.
Area of Science:
- Physiology
- Neonatal Medicine
- Gastroenterology
Background:
- The intestinal response to feeding is crucial for nutrient absorption and growth.
- Understanding age-related changes in intestinal hemodynamics is vital for neonatal care.
- Previous research has not fully elucidated the specific hemodynamic and oxygenation patterns in response to feeding across early life stages.
Purpose of the Study:
- To investigate age-dependent differences in intestinal blood flow and oxygenation following a milk feeding in piglets.
- To compare the compensatory mechanisms for increased oxygen demand during feeding in neonatal and older piglets.
- To identify potential risks for intestinal injury in newborns due to feeding-induced hemodynamic changes.
Main Methods:
- Utilized an isolated jejunoileum loop in piglets of varying ages (1-day to 1-month-old).
- Measured intestinal blood flow, arteriovenous oxygen difference, venous pressure, and capillary pressure.
- Employed radioactive microspheres for fractionated blood flow analysis and calculated oxygen uptake and vascular resistance.
Main Results:
- Postprandial oxygen uptake increased similarly in all age groups after milk formula instillation.
- Never-nursed newborns increased oxygen uptake via enhanced oxygen extraction without altering total blood flow.
- Older piglets (3-day, 2-wk, 1-mo) increased oxygen uptake through a combination of increased blood flow and oxygen extraction.
- Mucosal blood flow increased similarly across all ages, but in never-nursed newborns, this occurred at the expense of blood flow to other intestinal layers.
Conclusions:
- Newborn intestinal oxygen extraction and mucosal blood flow may be near maximal during feeding alone.
- Never-nursed newborns are at a higher risk of intestinal tissue hypoxia and mucosal injury when facing additional cardiovascular stress.
- These findings highlight the vulnerability of the neonatal gut and the importance of adequate circulatory support during feeding.