Objective   To investigate the role of phospholipase Cβ1 (PLCβ1) in the glucose-stimulated insulin secretion (GSIS).    Methods   ①Glucose at the concentrations of 10

20

40

80 mol/L and 100 mmol/L was used to treat INS-1 cells respectively for 40 min. The content of insulin in the INS-1 supernatant was detected for the optimal concentration of glucose. Then the decided concentration was used to the cells for 20

40

60

80 and 120 min respectively for the optimal time to induce insulin secretion. ②RT-PCR was used to detect the expression of PLCβ1 at the optimal glucose concentration for the optimal time.  ③Eukaryotic expression vector PCMV-HA-PLCβ1 was constrcted and then transiently transfected into INS-1 cells under the optimal concentration and treatment time. The PLCβ1 protein was detected by Western blot analysis.  ④Rat insulin ELISA kit was used to detect the content of insulin in the INS-1 supernatant.    Results   Exposed to INS-1 cells to 40 mmol/L glucose for 60 min

the content of insulin secretion reached the maximum and RT-PCR indicated the expression of PLCβ1 was raised. Compared to the control [(0.740±0.091) ng/ml]

the insulin’s content in the supernatant of INS-1 cells with overexpressed PLCβ1 was raised [(1.906±0.080) ng/ml] (P0.01).    Conclusion   Transient overexpression of PLCβ1 in INS-1 cells improves the insulin secretion

so PLCβ1 probably participates in the signal transduction pathway of GSIS in INS-1 cells.