Figure 1.

Upper panel: a donor strip is stitched onto the bioassay tissue creating a ‘sandwich’-like layered preparation. Isometric tension is recorded from the bioassay strip and the donor tissue does not directly contribute to the recorded response. Lower panel: acetylcholine-induced contractions only occurred when the donor strip contained endothelium. The experiment was performed in the presence of nitro-l-arginine and tetrahydrobiopterin to optimize the EDCF-mediated response (reproduced from Vanhoutte et al. 2005, with permission).