Fig. 3.
Phorbol 12,13-dibutyrate-induced contraction of coronary artery is inhibited by PKC and NADPH oxidase inhibitors. PKC activator phorbol 12,13-dibutyrate (PDBu; 10 μM) increased force generation in isolated BCA (n = 25–30) in a time-dependent manner. Pretreatment of BCA with PKC inhibitors chelerythrine (Chel; A), staurosporine (Stauro; B), and calphostin C (Cal; C) decreased the force generation evoked by PDBu. Contraction evoked by PDBu is not attenuated by superoxide scavengers tiron or peg-superoxide dismutase (300 U/ml SOD; D) but decreased significantly by hydrogen peroxide scavengers ebselen (10 μM Eb; E) and peg-catalase (150 U/ml peg-Cat; E), and by NADPH oxidase inhibitors diphenyleneiodonium (10 μM DPI; F) and gp91ds-tat (50 μM; F). Vehicle control has no effect on PDBu-induced contraction of coronary artery (G).