Figure 6. In vivo sibutramine administration increases the potency of prazosin-induced antagonism of epididymal tension to tyramine.

Concentration-reponse curves to tyramine in the absence and presence of prazosin 10 nM (PZS) in the epididymal cauda from vehicle (A) and sibutramine (B) treated rats. Numbers under the arrows indicate the reduction in the potency of tyramine-induced tension of epididymal segments evaluated at 37% of maximal response of control curves of both groups. Data are mean ± SEM of tissues from 3 rats/group.