Objective To study the effects of benzyl propionate nandrolone (BPN ) on the nicotinamide phosphoribosyl transferase (Nampt), insulin receptor substeate-2 (IRS-2 )and pancreatic duodenal homeobox-1 (PDX-1)expressions, cell cycle changes as well as insulin secretion in pancreatic islet cell NIT-1 lines, and to explore the influence of BPN in the Nampte xpression in NIT-1 cells and insulin signaling molecules in high glucose oxidation stress.Methods The NIT-1 cells were cultured with different concentrations (5.6,11.1,16.7,and 27.6 mmol·L-1)of glucose,then they were treated with 10 mg·L-1 BPN for 48 h with no BPN treatment as corresponding control groups.The expression levels of Nampt,IRS-2,and PDX-1 were tested by Western blotting assay.The changes of cell cycle were determined by FCM and the cell insulin secretion levels were measured with radioimmunoassay.Results Compared with corresponding control groups,the expression levels of Nampt,IRS-2, and PDX-1 proteins in the NIT-1 cells in various BPM groups were increased (P<0.05 or P<0.01).The G0/G1 phase arrest was relieved (P<0.01)when the cells was cultured in low glucose (5.6 mmol·L-1 )condition,and the G2/M block was remitted significantly in high glucose (27.6 mmol·L-1 )condition (P<0.01),furthermore, the cell insulin secretion was promoted compared with control groups except 1 1.1 mmol· L-1 glucose group (P<0.01).Conclusion BPN can promote the expression levels of Nampt,ISR-2 and PDX-1 proteins in NIT-1 cells. There is close relationship between the Nampt expression in NIT-1 cells and insulin signaling pathway and BPN prevents the cells from insulin resistance.