title: Capsaicin alleviates abnormal intestinal motility through regulation of enteric motor neurons and MLCK activity: Relevance to intestinal motility disorders.
abstract: METHODS
  Capsaicin is an active component of chili peppers, having diverse effects. However, the effects of capsaicin on intestinal motility are still controversial. The present study aimed to investigate the effects of capsaicin on intestinal motility disorder and uncover related mechanisms.
  
  
  RESULTS
  A rat model with intestinal motility disorder was established in vitro through adding different stimuli into tissue bath; in vivo using constipation and diarrhea model, respectively. Capsaicin exerted dual effects on intestinal motility, i.e. the relaxation and contraction of jejunum induced by corresponding stimulus were, respectively, regulated to be normal contraction by capsaicin. The mechanisms underlined capsaicin-induced dual effects were investigated using Western blotting, qRT-PCR, and whole-cell patch clamp, respectively. Results showed that cholinergic excitatory nerves, adrenergic nerves, and neurons containing nitric oxide synthase, which are the main muscle motor neurons in enteric nervous system (ENS), are involved in capsaicin-induced dual effects. The competition for regulation of Ca(2+) influx by capsaicin induced the interaction with components of the ENS. Capsaicin significantly increased myosin light chain kinase (MLCK) expression and myosin phosphorylation extent in jejunal segments of constipation-prominent rats and significantly decreased MLCK expression and myosin phosphorylation extent in jejunal segments of diarrhea-prominent rats.
  
  
  CONCLUSIONS
  In summary, capsaicin alleviates abnormal intestinal motility through regulating enteric motor neurons and MLCK activity, which is beneficial for the treatment of gastrointestinal motility disorders.
authors.affiliation: Department of Pharmacology, Dalian Medical University, Dalian, Liaoning Province, China.|Laboratory Animal Center, Dalian Medical University, Dalian, Liaoning Province, China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Pharmacology, Dalian Medical University, Dalian, Liaoning Province, China.
authors.forename: Yongjian
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Department of Pharmacology, Dalian Medical University, Dalian, Liaoning Province, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Pharmacology, Dalian Medical University, Dalian, Liaoning Province, China.
authors.forename: Zeyao
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Laboratory Animal Center, Dalian Medical University, Dalian, Liaoning Province, China.
authors.forename: Jingyu
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Pharmacology, Dalian Medical University, Dalian, Liaoning Province, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pharmacology, Dalian Medical University, Dalian, Liaoning Province, China.
authors.forename: Jihong
authors.initials: J
authors.lastname: Yao
mesh_terms: D000818:Animals; D020013:Calcium Signaling; D002211:Capsaicin / Q000378:metabolism / Q000627:therapeutic use*; D002478:Cells, Cultured; D003248:Constipation / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D003967:Diarrhea / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D019587:Dietary Supplements; D017615:Enteric Nervous System / Q000378:metabolism* / Q000503:physiopathology; D005765:Gastrointestinal Agents / Q000378:metabolism / Q000627:therapeutic use*; D007413:Intestinal Mucosa / Q000294:innervation / Q000378:metabolism / Q000503:physiopathology; D007583:Jejunum / Q000294:innervation / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009046:Motor Neurons / Q000378:metabolism; D009130:Muscle, Smooth / Q000294:innervation / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009219:Myosin-Light-Chain Kinase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017207:Rats, Sprague-Dawley; D024745:Smooth Muscle Myosins / Q000378:metabolism
chemical_list: D005765:Gastrointestinal Agents; D009219:Myosin-Light-Chain Kinase; D024745:Smooth Muscle Myosins; D002211:Capsaicin
keywords: Capsaicin; Contraction; Enteric nervous system; MLCK; Motility