[Rate of gluconeogenesis in the hepatocytes of the developing chick embryo]

Area of Science:

• Biochemistry
• Developmental Biology
• Cellular Metabolism

Background:

• Gluconeogenesis is a vital metabolic pathway for glucose homeostasis.
• Understanding the developmental regulation of gluconeogenesis is crucial for avian physiology.
• Hepatocytes are the primary site of gluconeogenesis in the liver.

Purpose of the Study:

• To investigate the developmental changes in the rate of gluconeogenesis from lactate in chick embryo and post-hatch chicken hepatocytes.
• To compare gluconeogenesis rates using lactate as a precursor across different developmental stages.

Main Methods:

• Isolation of hepatocytes from developing chick embryos (various stages) and one-day-old chickens.
• Measurement of the rate of glucose formation from lactate in isolated hepatocytes.
• Analysis of gluconeogenesis rates at different developmental time points.

Main Results:

• The maximum rate of gluconeogenesis was observed in hepatocytes from 16-17 day old chick embryos.
• A significant decrease in gluconeogenesis rate was detected in hepatocytes from embryos just before hatching.
• Further reduction in gluconeogenesis rate was noted in one-day-old chickens, with similar patterns for endogenous precursors and lactate.

Conclusions:

• Hepatocyte gluconeogenesis from lactate exhibits a distinct developmental pattern in chick embryos, peaking before hatching.
• The transition to post-hatch life is associated with a marked decline in the capacity for gluconeogenesis.
• These findings highlight critical developmental shifts in avian glucose metabolism.