Pancreatic alpha cell function in the fetal and newborn pig

Area of Science:

• Endocrinology
• Fetal Physiology
• Neonatal Metabolism

Background:

• Glucagon plays a crucial role in glucose homeostasis.
• Understanding fetal and neonatal glucagon regulation is vital for metabolic health.
• Limited data exists on fetal glucagon dynamics in vivo during late gestation.

Purpose of the Study:

• To investigate plasma glucagon concentrations in chronically catheterized fetal pigs during late gestation.
• To assess the responsiveness of fetal alpha cells to stimuli.
• To compare glucagon levels between chronically catheterized and anesthetized fetuses, and to examine glucagon levels at birth in relation to acid-base status.

Main Methods:

• Plasma glucagon levels were measured in chronically catheterized fetal pigs.
• Arginine infusion was used to stimulate glucagon release.
• Glucagon concentrations were compared between catheterized and anesthetized fetuses.
• Glucagon levels in newborn piglets were analyzed in relation to blood pH.

Main Results:

• Plasma glucagon concentrations increased with gestational age in both groups.
• Arginine infusion stimulated glucagon release in late-gestation fetuses.
• Glucagon levels were higher in anesthetized fetuses compared to catheterized fetuses.
• Newborn piglets with acidaemia exhibited significantly higher plasma glucagon levels than those with normal pH.
• A negative correlation was found between blood pH and plasma glucagon at birth.

Conclusions:

• Fetal alpha cells are functional and responsive in utero.
• Plasma glucagon levels are influenced by gestational age and acid-base status at birth.
• These findings provide insights into fetal and neonatal glucagon regulation and its potential role in metabolic adaptation.