title: Functional interaction between transforming growth factor alpha and capsaicin-sensitive sensory neurons in the rat stomach.
abstract: OBJECTIVE
  Transforming growth alpha (TGFalpha) and sensory neurons have been shown to promote gastric mucosal protection and healing. Aims were to examine in vitro interactions between gastric sensory neurons, the sensory neuropeptide calcitonin gene-related peptide (CGRP), and TGFalpha.
  
  
  METHODS
  Gastric mucosal/submucosal tissue fragments from Sprague-Dawley (SD) rats were incubated in short-term (30 min) culture. Peptide release into media and TGFalpha tissue content were measured by radioimmunoassay.
  
  
  RESULTS
  TGFalpha (1 x 10(-8) to 1 x 10(-6) M) caused dose-dependent stimulation of CGRP release. Maximal CGRP release (+87%) was observed with 1 x 10(-6) M TGFalpha: 28.6+/-3.8 vs. control of 15.5+/-2.7 pg/g tissue; P<0.05. Both CGRP (1 x 10(-7) to 1 x 10(-5) M) and capsaicin (1 x 10-(8) to 1 x 10(-6)M) significantly inhibited basal TGFalpha release in a dose-dependent fashion that ranged from -20% to -39%. In contrast, capsaicin-induced sensory denervation caused significant increases in both basal TGFalpha release and TGFalpha tissue content.
  
  
  CONCLUSIONS
  Function interactions between TGFalpha and gastric sensory neurons are suggested by the observations that (1) TGFalpha stimulated CGRP release from gastric sensory neurons; (2) CGRP and acute capsaicin treatment inhibited TGFalpha release and; (3) capsaicin-induced sensory denervation caused significant increases in both gastric TGFalpha basal release and tissue content.
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Oklahoma Health Sciences Center and Oklahoma City Department of Veterans Affaris Medical Center, USA.
authors.forename: Verapan
authors.initials: V
authors.lastname: Vongthavaravat
authors.forename: Layth A
authors.initials: LA
authors.lastname: Saymeh
authors.forename: Sikandar A
authors.initials: SA
authors.lastname: Mesiya
authors.forename: S Terence
authors.initials: ST
authors.lastname: Dunn
authors.forename: Richard F
authors.initials: RF
authors.lastname: Harty
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism* / Q000494:pharmacology; D002211:Capsaicin / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000294:innervation / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009475:Neurons, Afferent / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016211:Transforming Growth Factor alpha / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D016211:Transforming Growth Factor alpha; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin