Figure 3.

(a) A first addition of capsaicin (CAP 1, 1 μM) induced relaxation of bovine intraocular long posterior ciliary artery rings that was transient in nature. When the response had completely resolved, a second addition of capsaicin (CAP 2) failed to elicit relaxation, but produced a slight contraction. Furthermore, pretreatment with the CGRP₁ antagonist, CGRP_8–37 (1 μM), inhibited the relaxant response to a first addition of capsaicin. (b) CGRP (0.1–300 nM) induced concentration-dependent relaxation and this was inhibited following pretreatment with the CGRP₁ antagonist, CGRP_8–37 (1 and 5 μM). Data are mean±s.e.m.; n⩾8; ^*P<0.05 indicates difference from control.