Fig. 7.

a Log concentration–response relaxation curves to 5′-N-ethylcarboxamidoadenosine (NECA), on 1 μM noradrenaline (NA)- (control, open circle) or 60 mM K⁺ rich physiological saline solution (KPSS)-precontracted pig prostatic small arteries, in the absence (closed circle) and presence (closed square) of N^G-nitro-l-arginine (l-NOARG, 100 μM). Concentration–response relaxation curves to NECA in the absence (open circle) and presence (closed circle) of iberiotoxin (IbTX, 100 nM) (b), 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM 34, 20 nM) (c), or apamin (0.5 μM) (d), on 1 μM NA-precontracted rings. Results are expressed as a percentage of the NA-induced contraction and represent mean ± s.e.m. of six to seven arteries. *^,#P < 0.05 versus control and KPSS, respectively (paired t test for paired observations and analysis of variance and an a posteriori Bonferroni method for multiple comparisons)