Postischemic liver damage in rats: amino acid analysis and morphometric studies

Area of Science:

• Hepatology
• Biochemistry
• Surgical Research

Background:

• Normothermic liver ischemia is a critical factor in liver transplantation and surgery.
• Understanding the biochemical and cellular changes during ischemia-reperfusion is vital for improving outcomes.

Purpose of the Study:

• To investigate the effects of varying durations of normothermic total liver ischemia and subsequent reperfusion on amino acid profiles and hepatocyte integrity.
• To evaluate the impact of ischemia-reperfusion on animal survival rates.

Main Methods:

• Induction of normothermic total liver ischemia with transient portal decompression and venous bypass in an animal model.
• Measurement of total and individual amino acids in liver tissue and plasma.
• Assessment of organelle disintegration via electron microscopy.
• Monitoring of animal survival rates post-ischemia and reperfusion.

Main Results:

• Liver amino acids increased after >120 min ischemia without reperfusion; they decreased after ischemia with reperfusion.
• Plasma amino acids significantly increased after >120 min ischemia, with altered patterns depending on reperfusion.
• Organelle damage (mitochondrial degradation, autophagic vacuoles) steeply increased after >120 min ischemia.
• Survival rates decreased with longer ischemia durations (35% at 60 min, 27% at 90 min, 25% at 120 min).

Conclusions:

• Hepatocyte necrosis and protein degradation begin around 2 hours of ischemia, correlating with low survival rates.
• Amino acids are released from the liver into the plasma during ischemia-reperfusion, altering plasma amino acid patterns.
• Reperfusion partially restores plasma amino acid balance, but significant cellular damage limits overall recovery and survival.