Immunohistochemical and morphometric study of hepatocyte proliferation in 18-days old infant rats after a mechanical trauma being administered «Suvar» biologically active substance

Aim. Morphometric and immunohistochemical study of hepatocyte proliferative activity in 18-days-old infant rates after a mechanical trauma of the liver.

Methods. After an artificial mechanical injury of the liver with a steel needle in 18-days old infant rats, a biologically active substance «Suvar» in a dose of 50 mg/kg (n=36) was administered to animals. After animals were withdrawn from the experiment, a morphometric study (where the number of mitoses of hepatocytes for every 7000 cells were calculated) and immunohistochemistry of liver tissue were performed. For the immunohistochemistry, two commercially available monoclonal antibodies kits (manufactured by «Santa Cruz») were used: (1) proliferative activity marker Ki-67; (2) apoptosis marker bcl-2. Immunohistochemistry was performed according to standard protocol. Thirty-six operated infant rats, in whom the biologically active substance was not administered, were analyzed as the controls.

Results. The number of ki-67 positive hepatocytes in experimental animals on the 3rd, 5th,7th and the 9th day after the operation was significantly higher compared to controls. This was in accordance with the changes of the number of mitoses in hepatocytes, where the greatest number of mitoses was also registered on 3rd, 5th,7th and the 9th day. Both in experimental and in control infant rats, only single cells marked bcl-2 antibodies were found. The gained results support the opinion of the majority of the researchers that the liver regenerates mainly due to hepatocyte proliferation.

Conclusion. Morphometric study and immunohistochemistry confirmed that biologically active substance «Suvar» stimulates hepatocyte proliferation of hepatic cells, allowing better healing of liver injury compared to control animals.