Iron absorption in the everted chicken intestine

Area of Science:

• Animal Physiology
• Gastrointestinal Physiology
• Nutritional Biochemistry

Background:

• Understanding iron absorption in poultry is crucial for optimizing nutrition.
• The chicken intestine plays a key role in nutrient assimilation.
• Previous research has established methods for studying intestinal transport in vitro.

Purpose of the Study:

• To investigate the kinetics of iron uptake and transfer across the chicken intestinal mucosa.
• To determine the influence of iron concentration on mucosal uptake and serosal transfer.
• To explore potential saturation mechanisms and time-dependent changes in iron transport.

Main Methods:

• Everted intestinal sac technique using chicken intestines from 2-4 week old males.
• Incubation in a glucose-balanced ionic solution with varying iron concentrations (0.01-1 mM) and 59Fe tracer.
• Measurement of mucosal iron uptake and serosal fluid transfer at multiple time points (1-20 min).
• Assessment of intestinal sac viability via manometric oxygen evaluation.

Main Results:

• Mucosal iron uptake demonstrated a direct proportionality to iron concentration.
• Serosal iron transfer exhibited saturation kinetics, consistent in both duodenum and jejunum.
• Iron transfer decreased over time, indicating a possible serosal-to-mucosal reflux.
• Metabolic inhibitors (sodium azide, dinitrophenol) did not affect iron transport.

Conclusions:

• Chicken intestinal iron absorption involves concentration-dependent mucosal uptake and saturable serosal transfer.
• A time-dependent decrease in transfer suggests a potential reflux mechanism.
• Iron transport is not significantly inhibited by the tested metabolic inhibitors, implying passive or facilitated transport pathways.