Fig. 4. Glucose induces VSMC contraction through inhibition of MLCP.

A The effects of glucose (30 mM) and Glu-Ins on intracellular Ca²⁺ in VSMCs. n = 5. B The effects of FCCP, nigericin, CH₃COO^- and NH₄⁺ on intracellular Ca²⁺ in VSMCs. n = 5. C The effects of Glu-Ins on vascular constriction in isolated aortas preincubated with either thapsigargin (TG) or BAPTA-AM. n = 5. D The effects of glucose (30 mM) on MLC phosphorylation in cultured VSMCs preincubated with either TG or BAPTA-AM. n = 5. E The effects of glucose (30 mM) on MLC phosphorylation in cultured VSMCs preincubated with either Y27632 or Fasudil. n = 5. F Glucose (30 mM) increased phosphorylation of MYPT1 and CPI-17 in cultured VSMCs. n = 5. G Nigericin and NH₄⁺ increased MYPT1 phosphorylation and FCCP and CH₃CHOO^- decreased MYPT1 phosphorylation in cultured VSMCs. n = 5. H Glucose (30 mM) showed little effects on both RhoA expression and activity in cultured VSMCs. n = 4. I Knockdown of RhoA did not block the effects of glucose (30 mM) on phosphorylation of MLC and MYPT1 in cultured VSMCs. n = 5. J Knockdown of MYPT1 impaired the effects of glucose (30 mM) on MLC phosphorylation in cultured VSMCs. n = 5. K The effects of TEMPO, mitoTEMPO, and α-CCA pretreatments on glucose influx-induced phosphorylation of MYPT1 and MLC in VSMCs. n = 5. Error bars represent SEM. ^*P < 0.05. ^**P < 0.01.