Effects of Gallium on Bilirubin and Aminotransferases in Rats

Background & Objective: Gallium is an element being used in medical imaging and chemotherapy and proved to be accumulated in the liver. Since no reports have been published on the  effects of gallium on hepatic functions (such as bilirubin and aminotransferases), the present study tends to investigate the long-term effects of gallium on hepatic funtions and the involved mechanism.

Materials & Methods: The experimental study carried on 35 rats. They were divided into 7groups each containing 5 rats. The first 3 groups(group A) received intraperitoneal injections of 5, 10 and 15 mg of gallium per kilogram of body weight for 30 days; while the later 3 other groups(group B) received the same amount of gallium for 60 days;  Rats in the control group had physiological saline in the same values. Bilirubin and aminoteransferases in their blood samples were measured.

Results: Analysis of the data showed that in the dose of 15 mg/kg for 30 days the activity of AST and ALT was increased 44.66% and 12.38% respectively. Total and direct bilirubin was also increased. In the rats receiving the same dose of gallium for 60 days. Compairing to control group , the levels of AST, ALT and total bilirubin was increased 301%, 594% and 900% respictively from which the difference of total bilirubin was statistically significant.

Discussion: Gallium accumulation in hepatocytes and its binding with –SH group on Na- K pump inhibits bilirubin secretion and its transport to biliary ducts. Since bilirubin plays a detergenic role, its accumulation in intramembrane spaces results in the destruction of cellular membrane and the release of aminotransferases into serum. Analysis of data showed 301% increase in AST activity as compared with that of the control group. Continuous administration of gallium not only led to the destruction of cellular and mitocondrial memberanes, but also released alanine aminotransferases into serum. The increase of ALT activity was 594.7% in comparison with the control group. Due to the interruption of bilirubin transport to biliary ducts, it’s serum level went up dramatically. Data analysis also indicated a 900% increase in bilirubin level which is attributed to the disruption in its transport to biliary ducts.