STRUCTURAL CHANGES IN RATS' LIVER DURING THE FIRST 2 WEEKS FOLLOWING 2/3 PARTIAL HEPATECTOMY

Area of Science:

• Hepatology
• Regenerative Medicine
• Vascular Biology

Background:

• Liver regeneration is a complex process crucial for restoring organ function after injury or resection.
• Understanding the dynamic changes in cellular and vascular architecture post-hepatectomy is vital for assessing recovery completeness.

Purpose of the Study:

• To investigate the temporal changes in hepatocyte morphology and sinusoidal network architecture following 2/3 liver resection in rats over a 2-week period.
• To evaluate the completeness of liver regeneration by analyzing structural and architectural alterations.

Main Methods:

• Histological, immunohistochemical, and morphometrical analyses of liver tissue.
• Electron microscopy of corrosion casts to examine the sinusoidal capillary network architecture.
• Comparative analysis between resected liver portions (control) and regenerated liver tissue at various time points (24h to 2 weeks).

Main Results:

• Hepatocyte size and shape, particularly in acinar zones 1 and 3, altered significantly over time.
• Formation of new intercellular connections, including atypical membrane protrusions, was observed.
• Sinusoidal network remodeling included dilated sinusoids, zigzag patterns, and evidence of vascular sprouting, leading to altered lobule shapes and sizes.

Conclusions:

• Despite restored liver mass, regeneration remains incomplete, characterized by persistent transformation of hepatocytes and the vascular network.
• These cellular and vascular changes fundamentally alter the spatial architecture of the liver lobules.
• The study highlights the dynamic and ongoing nature of liver regeneration beyond simple mass restoration.