Objective   To observe the expression of gap junction protein

connexin43 in cultured human renal tubular epithelial cells (HKCs) after the treatment with high glucose and insulin.    Methods   The normal HKCs were divided into 6 groups

that is

normal control group (5.5 mmol/L)

high glucose group (30 mmol/L)

insulin group (10

-9

mmol/L)

high insulin group (insulin 10

-7

mmol/L)

high glucose plus insulin group (glucose 30 mmol/L+ insulin 10

-9

mmol/L) and high glucose plus high insulin group (glucose 30 mmol/L+ insulin 10

-7

mmol/L). the expression of connexin43 protein in HKCs of different groups was detected by Immunofluorescence microscopy and RT-PCR at protein and mRNA

levels.    Results   Single insulin (10

-7

mmol/L

but not 10

-9

mmol/L) or high glucose (5.5 mmol/L) significantly down-regulated the connexin43 expression in HKCs (

P

<

0.05). However

When these two stimulus combined together

the expressions of connexin43 at mRNA and protein levels were obvious enhanced than those of normal control group. And the high glucose plus high insulin group had markedly increased expression in comparison to those of high glucose group.    Conclusion   Both insulin at certain dose and high glucose influence the expression of gap junction protein in HKCs. However

high-dose insulin can attenuate the impairment of gap junction resulting from the stimulation of high glucose.