Comparative study on external use of mercury-containing preparation Badu Shengji San in sensitive monitoring indicators of induced early renal injury

Abstract

To compare the sensitivity of early renal injury induced by mercury-containing medicine in rats, including urinary N-acetyl-beta-D-glucosdminidase (NAG), beta2-microglobulin (beta2-MG), retinol binding protein (RBP) and clusterin (CLU). Badu Shengji San(BDSJS), a mercury-containing preparation of traditional Chinese medicine, was adopted as the mercury contact drug. The lowest effective toxic dose was used to observe its effect on serum creatinine (SCr), blood urea nitrogen (BUN), and such early renal injury indicators as NAG, RBP, beta2-MG and CLU and compare the sensitivity of tested indicators. Compared to the broken skin group, groups with administration of 60 and 120 mg x kg(-1) doses of BDSJS showed no obvious difference in SCr and BUN when kidney indicators is remarkably increased and obvious pathological changes were found in kidney tubules but with significant increase in the urinary level of CLU and the levels of NAG and RBP. H&E staining of renal tubule showed that exposure of 30 mg x kg(-1) BDSJS had no significant morphological changes, but at the same concentrations, the level of RBP was markedly increased. Urinary beta2-MG levels were markedly decreased in BDSJS 30, 60 mg x kg(-1) group rats, whereas 120 mg x kg(-1) dose group showed no obvious change in urinary beta2-MG levels. Urinary RBP, NAG and CLU were more sensitive than SCr and BUN as indicators for early renal injury in the order of RBP > NAG > CLU, and urinary RBP, NAG would increase earlier than beta2-MG.