GRP78 expression at different concentrations of glucose by reverse transcription PCR. a Relative level of GRP78 at different glucose concentrations. In the H/H group, the relative level of GRP78 was higher. *p < 0.01 compared with the other groups. b When merged with the same glucose group, the relative level of GRP78 expression was higher in high glucose groups (H/H, H/M, and H/L). *p < 0.01 compared with the other groups. c When merged with the same glucose culture group, the relative level of GRP78 was higher in high glucose culture groups (H/L, M/L, and L/L).*p < 0.01 compared with the other groups