The Protective Effect of Insulin and/or Heparin on PAECs Injured by High Glucose. PAECs were treated with glucose (30 mM), glucose plus insulin (1 U/ml), glucose plus heparin (0.5 μ g/ml) and glucose plus insulin plus heparin for seven days. Cell medium was changed and fresh reagents were added every other day. Cells were counted and LDH release to medium was determined 48 hrs after the last addition of reagents. Results are expressed as mean +/- SE of three dishes per group. Significantly different than a, control; b, glucose; c, glucose + heparin; d, glucose + insulin (P < 0.01) (one-way ANOVA).