Figure 5.

The effect of pre-incubation with insulin on H₂O₂ constriction is dependent on BKCa channels. Chorionic vein rings were pre-incubated (30 min, 5%CO₂, 37°C) in absence (control) or presence of 10 nM insulin and/or 1 mM tetraethylammonium (TEA; A), 100 nM iberiotoxin (IbTx; B), or 30 nM wortmannin (C). After these treatments, vessels were exposed to hydrogen peroxide (H₂O₂). In (D) the effects are shown of treatments on maximal constriction induced by 100 μM (1 × 10⁻⁴ M) H₂O₂. ^*P < 0.05, ^**P < 0.01 vs. values in the absence of insulin. ^†P < 0.05 vs. values in insulin treated vessels. Values are mean ± S.E.M. (n = 5–7).