Effect of inflammation of enteric nerves. Cytokine-induced changes in neurotransmitter content and release.

The results of our previously published work provide evidence of inflammation-induced functional disturbances in the enteric nervous system. Data presented in this paper describe our preliminary results indicating that the altered function in enteric nerves in the nematode-infected rat model of intestinal inflammation is mediated by interleukin-1. This is based on the ability of the exogenous cytokine to mimic changes observed in the model, and on the ability of a specific IL-1 antagonist to attenuate these changes. In addition, we have identified mechanisms underlying the actions of IL-1 in the myenteric plexus. Our data are consistent with a direct interaction between the cytokine and neural membranes. In addition, the delayed effect of IL-1 beta on neurotransmitter release appears to be due to the release of endogenous IL-1, most likely from macrophage-like cells in the myenteric plexus (Fig. 3). If such cells possess receptors for neuropeptides, as has been found with macrophages elsewhere in the gut, a neuroimmune axis would exist in the myenteric plexus. Thus, the finding of a source of IL-1 in the plexus of the noninflamed intestine invites speculation on a neuromodulatory role of the cytokine within the enteric nervous system.