Figure 7.
En face confocal microscopy and phosphotyrosine immunolabeling of native rabbit aortic endothelial cells fixed at different levels of vessel precontraction. Rabbit aortic rings under passive tension of 2 g (A) were contracted under isometric conditions with PGF2α to 15% (B), 30% (C), and 40% (D–F) of the maximum phenylephrine-induced contraction. Experiments were performed in the absence and presence of 5 μM herbimycin A (E) and 100 μM genistein (F). Once a stable contraction was achieved, rings were fixed and prepared as described in Materials and Methods. Identical results were obtained in three additional experimental series. (Bar = 10 μm.)