(A) Chromatograms of tissue superfusates collected before (control) and during nAChR stimulation with epibatidine (500 μM, 30 s) in WM and CM preparations of monkey colon. Small amounts of ATP and β-NAD+ were present in WM and CM superfusates in the absence of agonist. Epibatidine evoked release of ATP and β-NAD+ in WM preparations, but not in CM preparations. Scale applies to all chromatograms. LU, luminescence units. (B) Averaged data are means ± SEM, showing epibatidine-evoked release of ATP (left) and β-NAD+ (right) from monkey WM and CM preparations. Overflow (femtomoles per milligram of tissue) is the overflow during nAChR activation less spontaneous overflow. Overflow of ATP and β-NAD+ was significantly less in CM preparations. Asterisks denote significant differences from WM release (*P < 0.05, **P < 0.01); number of experiments in parenthesis.