Expression And Significance Of Bmp-2and Bmp-4in Regenerated Liver Of Exogenous Noggin Model Rats

Obiective By the interference of exogenous Noggin, studying the effects of BMP-2and BMP-4on the process of liver regeneration after partial hepatectomy(PH) in wistar rats.Methods Eighty healthy and male Wistar rats were randomly divided into4groups.Taking8rats as normal control(NC) group,another72majority male Wistar rats were performed Partial hepatectomy according to Higgins classical method.It was confirmed that PH was successfully formed.PH model rats were divided into three groups:normal sodium group(NS, n=24), low dose Noggin group(NL, n=24),high dose Noggin group(NH, n=24).To observe the change of liver regeneration rate by measuring the preoperative and postoperative(12h、48h、72h) rats weight and muting liver weight after partial hepatectomy (12,48and72h).To study the expression of BMP-2and BMP-4in the regenerated liver by the method of immunohistochemistry at different time points(0h、12h、48h、72h).Results1.Liver regeneration rate in all groups were significantly increased gradually during0-72h than NC group after PH (P<0.01).Liver regeneration rate in NL、NH groups were significantly decreased than NS group at12h after PH (P<0.01). There were no significantly differences among three groups at48、72h after PH (P>0.05).2.The expression of BMP-2in the hepatic tissue with each model rat group all presented at eaqual pace at Oh point, NS、NL、NH groups were significantly decreased at12h after PH(P<0.01), the expression of BMP-2in NL、NH groups were significantly decreased than NS group at12h after PH (P<0.01) and it in NH groups were significantly decreased than NL group, the difference has statistical significance (P<0.01).The expression of BMP-2in each model rat group at48h were significantly increased than they at12h but there were lower than they at72h, the difference has statistical significance (P<0.01); At this time, the expression of BMP-2in NS group were significantly increased than NL group and NH group, the difference among three groups has statistical significance (P<0.01), but the difference between NL group and NH group has no statistical significance (P>0.05).The expression of BMP-2in each model rat group at72h were highest in three time points but it still lower than NC group, the difference has statistical significance (P<0.01);At this time, the expression of BMP-2in NS group were significantly increased than NL group and NH group, it has statistical significance among three groups (P<0.01), the difference between NL group and NH group has no statistical significance (P>0.05). 3. The expression of BMP-4in the hepatic tissue with each model rat group all presented at eaqual pace at Oh point, they all begin to decrease at12h after PH and drop to the lowest at48h and start to upswing; The expression of BMP-4continue to upswing at72h but they were lower than normal control group.It has statistical significance among NS, NL and NH group at each time point(12、48、72h)(P<0.05)4. There is negative correlation between liver regeneration rate and the gray value of BMP-2in each group (rNS=-0.853,P<0.01;rNL=-0.780,P<0.01;rNH=-0.872,P<0.01).5.There has no correlation between liver regeneration rate and the gray value of BMP-4in each group (rNS=0.169,P>0.05; rNL=0.350,P>0.05;rNH=0.218,P>0.05).Conclusions1. BMP-2is a negative regulator of hepatocyte proliferation downregulated in the regenerated liver. The sharply decrease of BMP-2in the initial stage of liver regeneration in order to decrease the inhibition of liver regeneration. But along with the progression of liver regeneration, BMP-2begin to upswing in order to inhibit the eteral proliferation of hepatocyte.2.The negative regulator of BMP-2on liver regeneration may be concerned with the density of BMP-2, it may have the limitation or scope both of the dose and density.3.BMP-4regulate the process of liver regeneration,it may participate the process of the formation of liver nonparenchymal cell and hepatic cord,and it may participate the process of liver contour.