Insulin Influences The Expressions Of Insulin Receptor And G Protein Binding With Insulin Receptor In βTC-3 Cell

Objective:To explore the effects of exogenous insulin on the expression of insulin receptor and G protein (Gαo) binding with insulin receptor in mouse insulinomaβTC-3 cells.Methods:1. The expression of insulin receptors inβTC-3 cells in different incubation time (0 min 30min 60min 120min 240min) exposure to 100μIU/ml insulin was analyzed by immune fluorescence cytochemistry combined with laser scanning confocal microscopy. Semi-quantitative analysis of fluorescence intensity of insulin receptors was determined by Image Pro Plus 6.0 software.2. The expressions of insulin receptors and Gαo protein binding with insulin receptors inβTC-3 cells in different incubation time (0 min 60min 240min) exposure to 100μIU/ml insulin were analyzed by co-immunoprecipitation combined with western blot.Gray scan of insulin receptors and Gαo was determined by Bandscan software.Results:1. The expression of insulin receptors was decreased significantly at 30,60,120 and 240 min compared with that of 0 min after incubated with 100μIU/ml insulin(P﹤0.05).2. The expressions of insulin receptors at 60min and 240min were decreased significantly compared with that of 0 min after incubated with 100μIU/ml insulin(P﹤0.05).The expression of Gαo protein binding with insulin receptors at 60min was increased significantly compared with that of 0 min after incubated with 100μIU/ml insulin(P﹤0.05),but it was decreased obviously at 240 min compared with that of 0 min(P﹤0.05).Conclusions:1. The expression of insulin receptor inβTC3 cells was obviousiy decreased with high concentration insulin incubation, which may be one of the mechanisms of insulin resistance.2. The expressions of insulin receptors inβTC-3 cells were decreased significantly exposure to high level insulin incubation.The expressions of Gαo protein binding with insulin receptors was firstly increased and then decreased significantly exposure to high level insulin incubation. The change of Gαo protein expression may be related to the function regulation of insulin receptor.