Double-staining immunohistochemistry showing the distribution of P2X7 receptors (green) and the neuronal marker HuC/D (red) in the myenteric plexus of colonic cryosections from control (A; normal) or DNBS-treated (B; colitis) rats.

<p>Nuclei were stained with TOTO-3. Scale bar: 21 µm. Enlarged view of HuC/D⁺ and P2X7⁺ cells in the myenteric ganglia of normal and colitis rats from boxed area in overlay (scale bar = 10 µm). LM, longitudinal muscle; CM, circular muscle; MG, myenteric ganglia. Isotype fluorescent image was obtained by labeling with streptavidin conjugated with Alexa Fluor 555 in presence of normal mouse antiserum instead of the primary antibody.</p

Effects of A804598 (0.01µM) on contractions evoked by sES (0.5 ms, 10 Hz, 30 mA, 10 s) in colonic longitudinal muscle preparations maintained in Krebs solution added with apyrase (10 U/ml).

<p>Each column represents the mean±SEM obtained from 6 experiments. *P<0.05, versus control.</p

Double immunostaining showing the expression of P2X7 receptors (green) and the glial marker GFAP (red) in myenteric plexus of colonic cryosections from control (A; normal) and DNBS-treated (B; colitis) rats.

<p>Nuclei were stained with TOTO-3. Scale bar: 21 µm. Enlarged view of GFAP⁺ and P2X7⁺ cells in the myenteric ganglia of normal and colitis rats from boxed area in overlay (scale bar = 10 µm). LM, longitudinal muscle; CM, circular muscle; MG, myenteric ganglia. Isotype fluorescent image was obtained by labeling with Alexa Fluor 555 conjugated secondary antibody in presence of normal mouse antiserum instead of the primary antibody.</p

Levels of fluorescence intensity of HuC/D⁺ neurons (A) or P2X7 receptors⁺ cells (B), expressed as arbitrary units (AU), in the myenteric ganglia or the colonic neuromuscular layer (MG, myenteric ganglia; LM, longitudinal muscle; CM, circular muscle), either in the absence (normal) or in the presence of colitis, respectively.

<p>*P<0.01 versus colitis.</p

Preparations of longitudinal smooth muscle isolated from normal (A) or DNBS-treated rats (colitis) (B).

<p>Effects of increasing concentrations of A804598 (0.001–10 µM) on contractions evoked by sES (0.5 ms, 10 Hz, 30 mA, 10 s) in preparations maintained in standard Krebs solution. Each column represents the mean±SEM obtained from 6 experiments. *P<0.05, versus control (CON).</p

Column graphs showing the effects of BzATP (1 µM) on contractions evoked by carbachol (1 µM) in colonic preparations obtained from normal or inflamed rats (colitis) maintained in Krebs solution containing tetrodotoxin (1 µM).

<p>Each column represents the mean±SEM value obtained from eight experiments. CARB, carbachol.</p