Figure 2.

The time course and mechanism of recovery of responsiveness to trypsin (0.1 u ml⁻¹) following desensitization with thermolysin (0.01–1 u ml⁻¹, 20 min) in U46619-contracted rings of pig coronary artery. (a) Endothelium-dependent relaxations to trypsin (0.1 u ml⁻¹) were determined in matched time control and thermolysin-treated arteries at the times indicated after thermolysin washout. (b) Relaxations to trypsin (0.1 u ml⁻¹) 150 min after treatment washout, in artery preparations treated with actinomycin D (ActD; 2 μM), brefeldin A (BrefA; 10 μM) or cycloheximide (Cyclo; 100 μM) alone or after prior treatment with thermolysin (Therm; 0.01–1 u ml⁻¹, 20 min). Data are mean±s.e.mean from 4–6 experiments and are expressed as percentages of the maximum relaxation to isoprenaline (1 μM). ^*P<0.05 (ANOVA) vs thermolysin control group.