Agonists of proteinase-activated receptor 2 excite guinea pig ileal myenteric neurons

The effects of proteinase-activated receptor 2 (PAR2) agonists on the electrical properties of intact guinea pig ileal myenteric neurons were measured with intracellular microelectrodes. Approximately 52% of AH neurons and 41% of S neurons responded to pressure ejection of SLIGRL-NH2 or trypsin with a prolonged depolarization that was often accompanied by increased excitability. When added to the bathing solution, trypsin caused a concentration-dependent depolarization of responding neurons with an estimated EC50 value of 87 nM. Collectively, these novel observations indicate that PAR2 excites a proportion of myenteric neurons, which may contribute to dysmotility during intestinal inflammation. (C) 2001 Elsevier Science B.V. All rights reserved.