Electrical behaviour of interleukin-1 beta (IL-1 beta) and prostaglandin-E2 (PGE2) on colonic myenteric neurones.
Abstract Intracellular recordings were used to examine the effects on electrical and synaptic behaviour of interleukin (IL)-1beta and prostaglandin E2(PGE2) on myenteric neurones of the guinea-pig colon. Application of IL-1beta and PGE2resulted in a concentration-dependent slow depolarization with enhanced spike discharge in, respectively, 45% (21/47) and 83% (33/41) of the impaled colonic neurones. Administration of IL-1beta in three neurones (6%) elicited a hyperpolarization. Responses remained during tetrodotoxin application, indicative of a direct effect of both substances on the impaled neurones. The effects of IL-1beta remained in the presence of indomethacine, a prostaglandin synthase inhibitor. Responses were seen in both nitric oxide synthase- and choline acetyl transferase-immunoreactive neurones. IL-1beta evoked a 26% reduction of the fast excitatory postsynaptic potential. These results indicate that the application of IL-1beta and PGE2evoke direct excitatory actions on a subset of myenteric neurones. For IL-1beta, direct inhibition and presynaptic inhibition of the fast excitatory postsynaptic potential has also been found. In the distal colon, responses to IL-1beta are not mediated through PGE2pathways.
Kelles
A
A
Center for G.I. Research K.U. Leuven, Belgium., University of Leuven, Leuven, Belgium.
Janssens
J
J
Tack
J
J
D000818:Animals; D003106:Colon / Q000187:drug effects / Q000502:physiology*; D015232:Dinoprostone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000494:pharmacology*; D009197:Myenteric Plexus / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*
D007375:Interleukin-1; D015232:Dinoprostone