Cellular Mechanisms of Myogenic Activity in Gastric Smooth Muscle.

• Suzuki Hikaru

  Department of Physiology, Nagoya City University Medical School

抄録

In many regions of the intestine, a thin layer of interstitial cells of Cajal (ICC) lie in the myenteric region, between the circular and longitudinal muscle layers. ICC are connected by gap junctions to surrounding ICC and also with circular and longitudinal smooth muscle cells, forming a large electrical syncytium. Damage of the ICC causes a disorder in the patterns of rhythmic activity. Isolated ICC produce a rhythmic oscillation of the membrane potential. All these observations have led to the suggestion that ICC may be the pacemaker cell responsible for intestinal activity. Gastric smooth muscles generate slow oscillatory membrane potential changes (slow waves) and spike potentials. The activity is considered to be linked to the metabolism in the cell. Three types of cells located in the gastric wall (circular and longitudinal smooth muscle cells and ICC) produce synchronized electrical responses with different shapes. The electrical responses appear to originate in ICC and then spread to the smooth muscle layers, indicating that ICC may also be the pacemaker cells responsible for gastric activity. However, isolated circular smooth muscle tissues spontaneously generate regenerative potentials, suggesting that there are at least two sites for the initiation of spontaneous activity in the stomach. Regenerative potentials persist in the presence of Ca-antagonists and are inhibited by agents which disrupt intracellular Ca²⁺ homeostasis. Depolarization of the membrane elicits regenerative potentials after a long delay and the potentials have long refractory periods. This suggests that an unidentified 2nd messenger may be formed during the delay between membrane depolarization and the initiation of a regenerative potential. In gastric muscles of mutant mice which do not express inositol trisphosphate (InsP₃) receptors, spike potentials but not slow waves are generated, suggesting the possible involvement of InsP₃ in the initiation of spontaneous activity.<br>

収録刊行物

• The Japanese Journal of Physiology

  The Japanese Journal of Physiology 50 (3), 289-301, 2000

  一般社団法人　日本生理学会

キーワード

• gastrointestinal muscle
• slow waves
• myogenic activity
• interstitial cells
• Ca release

詳細情報

• CRID: 1390001205041155456
• NII論文ID: 10008291245
• NII書誌ID: AA00691224
• DOI: 10.2170/jjphysiol.50.289
• COI: 1:CAS:528:DC%2BD3cXntFGju78%3D
• ISSN: 18811396
• ISSN: 0021521X
• ISSN: http://id.crossref.org/issn/0021521X
• NDL書誌ID: 5525733
• PubMed: 11016979
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I5525733
• Web Site: https://search.jamas.or.jp/link/ui/2001092152
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可