Sumei Liu

Jackie D Wood21
Hong-Zhen Hu18
Guo-Du Wang10
21Jackie D Wood
18Hong-Zhen Hu
10Guo-Du Wang
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BACKGROUND & AIMS Serine proteases are postulated to influence gastrointestinal function by stimulating protease-activated receptors (PARs). This study identified the effects on myenteric neurons of activating PARs and investigated underlying mechanisms of action. METHODS Intracellular electrophysiologic methods were used to study the effects of proteases(More)
Reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiological recording, and intraneuronal injection of the neuronal tracer biocytin were integrated in a study of the functional expression of corticotropin-releasing factor (CRF) receptors in the guinea pig enteric nervous system. RT-PCR revealed expression of CRF1(More)
BACKGROUND AND PURPOSE Urocortins (Ucns) 1, 2 and 3 are corticotropin-releasing factor (CRF)-related neuropeptides and may be involved in neural regulation of colonic motor functions. Nevertheless, details of the neural mechanism of action for Ucns have been unclear. We have, here, tested the hypothesis that Ucns act in the enteric nervous system (ENS) to(More)
Immunofluorescence was used to study immunoreactivity (IR) for corticotropin-releasing factor (CRF) in the guinea pig enteric nervous system. CRF-IR was expressed in both the myenteric and the submucosal plexuses of all regions of the large and small intestine and the myenteric plexus of the stomach. CRF-IR nerve fibers were present in the myenteric and(More)
Lubiprostone activates ClC-2 chloride channels in epithelia. It is approved for treatment of chronic idiopathic constipation in adults and constipation-predominate irritable bowel syndrome in women. We tested a hypothesis that lubiprostone can reverse the constipating action of morphine and investigated the mechanism of action. Short-circuit current (Isc)(More)
We tested the hypothesis that ATP is an enteric neurotransmitter that acts at P2Y1 excitatory purinergic receptors on intestinal secretomotor neurons to evoke neurogenic mucosal secretion in the guinea pig. Ussing chamber methods for studying neurogenic intestinal secretion were used to test the hypothesis. Application of ATP evoked concentration-dependent(More)
Mast cells express the substance P (SP) neurokinin 1 receptor and the calcitonin gene-related peptide (CGRP) receptor in guinea pig and human small intestine. Enzyme-linked immunoassay showed that activation of intramural afferents by antidromic electrical stimulation or by capsaicin released SP and CGRP from human and guinea pig intestinal segments.(More)
BACKGROUND/AIMS Functional gastrointestinal disorders are those in which no abnormal metabolic or physical processes, which can account for the symptoms, can be identified. The irritable bowel syndrome (IBS) is a significant functional disorder, which affects 10-20 percent of the population worldwide. Predominant symptoms of IBS are abnormal defecation(More)
ATP is a putative inhibitory neurotransmitter responsible for inhibitory junction potentials (IJPs) at neuromuscular junctions (IJPs) in the intestine. This study tested the hypothesis that the purinergic P2Y(1) receptor subtype mediates the IJPs. IJPs were evoked by focal electrical stimulation in the myenteric plexus and recorded with "sharp"(More)