ADA and infection: Our results show that: (i) under normal conditions, exogenous adenosine contracts longitudinal smooth muscle of intact rat ileum; (ii) in the presence of HSV-1 infection in the ENS, adenosine-mediated contractile response by A1 and A2A receptors is impaired at 1 and 6 weeks post-infection; (iii) latent HSV-1 infection in neurons influences the distribution of CD73, ADA and adenosine receptors in a distinct manner in ileal smooth muscle layers and myenteric plexus.