Fig. 5.
Cx40-specific inhibitor abolishes EDR in diabetic CAs but does not affect EDR in control CAs at the same concentration. A: representative record of vascular relaxation in CAs after application of a scramble peptide (left, indicated by S) or 40GAP27 (right, indicated by G). Each symbol indicates as follows: P, PGF2α; 9, 10−9 M ACh (same manner for 4∼8); N, sodium nitroprusside (SNP); W, wash. The concentration of 300 μM 40GAP27 exhibits no inhibitory effect on EDR, whereas 600 μM 40GAP27 starts to affect EDR in control CAs. However, 300 μM 40GAP27 is sufficient to inhibit EDR in diabetic CAs. B: dose-response curves of ACh-induced vasodilatation in control (n = 5) and diabetic (n = 5) CA rings treated with 300 μM scramble peptide and 300 μM 40GAP27. Data are expressed as means ± SE. *P < 0.05 vs. scramble peptide.