The Role of Hepatic Stellate Cells and Angiogenesis in Liver Regeneration Following Partial Hepatectomy in Adult Male Albino Rats: Histological and Immunohistochemical Study

Abstract

Introduction: Partial hepatectomy is indicated as the main curative approach for traumatic rupture of the hepatic parenchyma, and hepatocellular carcinoma. Hepatic stellate cells (HSCs) are vital and have a significant importance in their emerging role in hepatic regeneration.Aim of the Work: Study the role of hepatic stellate cells and angiogenesis in liver regeneration after 70% partial hepatectomy in adult male albino rats.Materials and Methods: Forty adult male albino rats(4-6months) weighing 150-200 gm were randomized into 5 groups of eight rats each; group I was the sham control group, and the animals were subjected to 70% partial hepatectomy in groups II, III, IV and V in which they were postoperatively sacrificed 3, 7, 14 and 21 days respectively. At the time of scarification specimens were taken for histological and immunohistochemical studies. H and E and immunohistochemical staining for proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF) and α-smooth muscle actin (α- SMA) were done. Image analysis and statistical analysis of the obtained results were performed.Results: The liver showed disturbed histological architecture with distortion of the neatly arranged hepatocyte plates in group II which was restored in the following groups. Wide distribution of Kupffer cells, was also noted in group II and continued in group III. The PCNA and VEGF activity showed significant positive reaction in groups II and III , insignificant positive immunoreaction was reported in groups IV and V . The α- SMA showed significant positive reaction in group II, insignificant immunoreaction was reported in the remaining other groups.Conclusion: Partial hepatectomy stimulated liver regeneration in the remaining liver lobes with reconstitution of most of the liver mass 21 days postoperatively. This regenerative process was associated with angiogenesis and HSCs activation as denoted by VEGF expression and α- SMA expression respectively.