Increased PIT1 and PIT2 Expression in Streptozotocin (STZ)-induced Diabetic Mice Contributes to Uptake of iAs(V)

Objective This study aimed to investigate the susceptibility of mice with streptozotocin(STZ)-induced diabetes mellitus (TIDM) to the uptake of pentavalent inorganic arsenic (iAs V ) and the possible molecular mechanism. Methods TIDM was induced in mice by STZ. TIDM and normal mice were treated with 15.0 mg/kg Na 2 HAsO 4 ·12H 2 O by intragastric administration. Then, the concentrations of arsenic in various tissues were measured by atomic fluorescence spectrometry. The gene expression levels of Pit1 and Pit2 were quantified by real-time RT-PCR, and their protein levels were detected by Western blotting in mouse heart, kidney, and liver tissues. Results The concentrations of arsenic in STZ-induced TIDM mouse tissues were higher at 2 h after intragastric administration of Na 2 HAsO 4 ·12H 2 O. Compared with the levels in normal mice, PIT1 and PIT2, which play a role in the uptake of iAs V , were upregulated in the livers and hearts of TIDM mice. PIT1 but not PIT2 was higher in TIDM mouse kidneys. The upregulation of Pit1 and Pit2 expression could be reversed by insulin treatment. Conclusion The increased uptake of iAs V in TIDM mouse tissues may be associated with increased PIT1 and/or PIT2 expression.