A Comparative Study Of Ultrasonographic Findings And Pathological Changes Of Rabbit Liver After Tamoxifen And Letrozole Administration

Objective:To observe Ultrasonic characteristics and pathological findings of rabbit liver after administration of tamoxifen and letrozole;to clarify if the pathological changes are the cause of fatty liver diagnosed by ultrasonography after administration of endocrine therapeutics.Methods:20 New Zealand rabbits were randomly divided into 2 groups(group A,group B),10 each group.Group A were given 5.0 mg/kg tamoxifen daily(gavage)+ ordinary fodder for 6 months.Group B were given 1.0mg /kg letrozole daily(gavage)+ ordinary fodder for 6 months.Before administration hepatic function,serum lipids,conventional liver sonogram and acoustic radiation force impulse imaging(ARFI)were obtained.After 6 months of tamoxifen and letrozole administration the above-mentioned laboratories and exams were obtained again,and the findings were analyzed and compared.Finally,rabbits were executed and hepatic samples were fixed and for microscopic observation.Results:Hepatic function: Aspartate Amino transaminase(AST)and Alanine Amino transaminase(ALT)of group A were elevated,there was a statistica l difference between before and after drug use.AST of group B was not elevated,while ALT of group B was elevated,there was a statistical difference between before and after drug use.AST of group A was higher than group B's,there was a statistical difference between group A and group B after drug us.Lipids: Triglyceride(TG)of group A was elevated after drug use,there was a statistical difference between before and after drug use.Total Cholesterol(TC)of group B was mildly elevated,there was a statistical difference between before and after drug use,however the measured values of TC were within normal limit before and after drug use.TG of group B was elevated after drug administration,there was a statistical difference between before and after drug use.The she-er speeds of both group A and group B were mildly elevated,there was a statistical difference between before and after drug administration.The sheer speed of group A was higher than B's,there was a statistical difference between group A and group B.Conventional ultrasound: In both group A and group B,hepatic capsules were not apparently thickened,the masses were not obviously enlarged,the shapes appeared plumpy,and the parenchymas were slightly hyper echogenic,comparatively mild dense,mild heterogeneous.Those sonographic characteristics were more prominent in group A than in group B.Pathology: There were clear lobular structures.Hepatic cells showed mild swelling,cytoplasm loosened.Occasional spotty necroses were seen in some areas.There were some congestion in interlobular vessles and central venules,some acidophilic degeneration,and associated with obvious macro vesicular steatosis in group A and associated with obvious vesicular steatosis in group B.Conclusion:Long-term administration of tamoxifen and letrozole will lead to somewhat hepatic function impairments and serum lipid changes,which reflect the abnormal findings of liver sonogram and pathology.However,these changes may not reach the extent to that a diagnosis of fatty liver sonogram is confirmed.