Signal Transduction Pathways Mediating Brain-gut Peptides And Cisapride Kinetic Effects On Gastric Smooth Muscle Cell

Gastrointestinal motility is under neural, humoral and myogenic control. Gastrointestinal peptides play the critical roles in the regulation of gastrointestinal motility, in which they act as neurotransmitters, neuromodulators and hormones. The brain-gut peptides, presented both in nervous system and in gastrointestinal system, interact with the specific receptors coupled with the guanine nucleotide-binding protein (G-protein) on the smooth muscle cell surface, activate a cascade of molecular events that mediate smooth muscle contraction and relaxation. The previous studies about the regulation of the brain-gut peptides to gastrointestinal motility were mainly on their effects by central nervous system, enteric nervous system and hormonal substances, but with the improvement of study, the intracellular signal transduction pathway of brain-gut peptides are becoming one of the most interested fields. Identification to signal transduction pathway of brain-gut peptides in gastrointestinal smooth muscle contraction and relaxation is very important both to understand the mechanism and to cure the gastrointestinal motility disorders.This study was to identify the signal transduction pathway of brain-gut peptides in the gastrointestinal smooth muscle cell. Excitatory brain-gut peptides, gastrin, motilin and CCK, and inhibitory brain-gut peptides, secretin and VIP, were involved in this study. The present experiments were mainly on the following aspects to: (1) determine the specific receptor subtypes of those brain-gut peptides. (2) identify the receptor-coupled G-protein. (3) elucidate the signaling cascades of brain-gut peptides in regulating gastric motility. (4)...