title: Signal transduction of bombesin-induced circular smooth muscle cell contraction in cat esophagus.
abstract: OBJECTIVE
  To investigate the mechanism of bombesin-induced circular smooth muscle cell contraction in cat esophagus.
  
  
  METHODS
  Specific G protein or phospholipase C involved in cat esophagus contraction was identified, muscle cells were permeabilized with saponin. After permeabilization of muscle cells, the Gi3 antibody inhibited bombesin-induced smooth muscle cell contraction.
  
  
  RESULTS
  Incubation of permeabilized circular muscle cells with PLC-beta3 antibody could inhibit bombesin-induced contraction. H-7, chelerythrine (PKC inhibitor) and genistein (protein tyrosine kinase inhibitor) inhibited bombesin-induced contraction, but DAG kinase inhibitor, R59949, could not inhibit it. To examine which mitogen-activated protein kinase (MAPK) was involved in bombesin-induced contraction, the specific MAPK inhibitors (MEK inhibitor, PD98059 and p38 MAPK inhibitor, SB202190) were used. Preincubation of PD98059 blocked the contraction induced by bombesin in a concentration-dependent manner. However, SB202190 had no effects on contraction.
  
  
  CONCLUSIONS
  Bombesin-induced circular muscle cell contraction in cat esophagus is madiated via a PKC or a PTK-dependent pathway or p44/p42 MAPK pathway.
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chung Ang University, Seoul 156-756, Republic of Korea.
authors.forename: Sung-Uk
authors.initials: SU
authors.lastname: Park
authors.forename: Chang-Yell
authors.initials: CY
authors.lastname: Shin
authors.forename: Jung-Su
authors.initials: JS
authors.lastname: Ryu
authors.forename: Hyen-O
authors.initials: HO
authors.lastname: La
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Song
authors.forename: Young-Sil
authors.initials: YS
authors.lastname: Min
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Kim
authors.forename: Uy-Dong
authors.initials: UD
authors.lastname: Sohn
mesh_terms: D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D002415:Cats; D004947:Esophagus / Q000187:drug effects* / Q000502:physiology; D007527:Isoenzymes / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000502:physiology; D054799:Phospholipase C beta; D011493:Protein Kinase C / Q000502:physiology; D043562:Receptors, G-Protein-Coupled / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D010738:Type C Phospholipases / Q000502:physiology
chemical_list: D007527:Isoenzymes; D043562:Receptors, G-Protein-Coupled; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; D054799:Phospholipase C beta; D001839:Bombesin