Abstract
Background & Aims: Like the heart, intestinal smooth muscles exhibit electrical rhythmicity, which originates in pacemaker cells surrounding the myenteric plexus, called interstitial cells of Cajal (ICC-MY). In large mammals, ICC also line septa (ICC-SEP) between circular muscle (CM) bundles, suggesting they might be necessary for activating muscle bundles. It is important to determine their functional significance, because a loss of ICC in humans is associated with disordered motility. Our aims were therefore to determine the role of ICC-SEP in activating the thick CM in the human jejunum. Methods: The mucosa and submucosa were removed and muscle strips were cut and pinned in cross-section so that the ICC-MY and ICC-SEP networks and the CM could be readily visualized. The ICC networks and CM were loaded with the Ca2+ indicator fluo-4, and pacemaker and muscle activity was recorded at 36.5 ± 0.5°C. Results: Ca2+ imaging revealed that pacemaker activity in human ICC-MY can entrain ICC-SEP to excite CM bundles. Unlike the heart, pacemaker activity in ICC-MY varied in amplitude, propagation distance, and direction, leading to a sporadic activation of ICC-SEP. Conclusions: ICC-SEP form a crucial conduction pathway for spreading excitation deep into muscle bundles of the human jejunum, necessary for motor patterns underlying mixing. A loss of these cells could severely affect motor activity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 907-917 |
| Number of pages | 11 |
| Journal | Gastroenterology |
| Volume | 133 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2007 |
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ASJC Scopus subject areas
- Gastroenterology
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Septal Interstitial Cells of Cajal Conduct Pacemaker Activity to Excite Muscle Bundles in Human Jejunum. / Lee, Hyun Tai; Hennig, Grant W.; Fleming, Neal; Keef, Kathleen D.; Spencer, Nick J.; Ward, Sean M.; Sanders, Kenton M.; Smith, Terence K.
In: Gastroenterology, Vol. 133, No. 3, 09.2007, p. 907-917.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Septal Interstitial Cells of Cajal Conduct Pacemaker Activity to Excite Muscle Bundles in Human Jejunum
AU - Lee, Hyun Tai
AU - Hennig, Grant W.
AU - Fleming, Neal
AU - Keef, Kathleen D.
AU - Spencer, Nick J.
AU - Ward, Sean M.
AU - Sanders, Kenton M.
AU - Smith, Terence K.
PY - 2007/9
Y1 - 2007/9
N2 - Background & Aims: Like the heart, intestinal smooth muscles exhibit electrical rhythmicity, which originates in pacemaker cells surrounding the myenteric plexus, called interstitial cells of Cajal (ICC-MY). In large mammals, ICC also line septa (ICC-SEP) between circular muscle (CM) bundles, suggesting they might be necessary for activating muscle bundles. It is important to determine their functional significance, because a loss of ICC in humans is associated with disordered motility. Our aims were therefore to determine the role of ICC-SEP in activating the thick CM in the human jejunum. Methods: The mucosa and submucosa were removed and muscle strips were cut and pinned in cross-section so that the ICC-MY and ICC-SEP networks and the CM could be readily visualized. The ICC networks and CM were loaded with the Ca2+ indicator fluo-4, and pacemaker and muscle activity was recorded at 36.5 ± 0.5°C. Results: Ca2+ imaging revealed that pacemaker activity in human ICC-MY can entrain ICC-SEP to excite CM bundles. Unlike the heart, pacemaker activity in ICC-MY varied in amplitude, propagation distance, and direction, leading to a sporadic activation of ICC-SEP. Conclusions: ICC-SEP form a crucial conduction pathway for spreading excitation deep into muscle bundles of the human jejunum, necessary for motor patterns underlying mixing. A loss of these cells could severely affect motor activity.
AB - Background & Aims: Like the heart, intestinal smooth muscles exhibit electrical rhythmicity, which originates in pacemaker cells surrounding the myenteric plexus, called interstitial cells of Cajal (ICC-MY). In large mammals, ICC also line septa (ICC-SEP) between circular muscle (CM) bundles, suggesting they might be necessary for activating muscle bundles. It is important to determine their functional significance, because a loss of ICC in humans is associated with disordered motility. Our aims were therefore to determine the role of ICC-SEP in activating the thick CM in the human jejunum. Methods: The mucosa and submucosa were removed and muscle strips were cut and pinned in cross-section so that the ICC-MY and ICC-SEP networks and the CM could be readily visualized. The ICC networks and CM were loaded with the Ca2+ indicator fluo-4, and pacemaker and muscle activity was recorded at 36.5 ± 0.5°C. Results: Ca2+ imaging revealed that pacemaker activity in human ICC-MY can entrain ICC-SEP to excite CM bundles. Unlike the heart, pacemaker activity in ICC-MY varied in amplitude, propagation distance, and direction, leading to a sporadic activation of ICC-SEP. Conclusions: ICC-SEP form a crucial conduction pathway for spreading excitation deep into muscle bundles of the human jejunum, necessary for motor patterns underlying mixing. A loss of these cells could severely affect motor activity.
UR - http://www.scopus.com/inward/record.url?scp=34548475275&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548475275&partnerID=8YFLogxK
U2 - 10.1053/j.gastro.2007.06.024
DO - 10.1053/j.gastro.2007.06.024
M3 - Article
C2 - 17678922
AN - SCOPUS:34548475275
VL - 133
SP - 907
EP - 917
JO - Gastroenterology
JF - Gastroenterology
SN - 0016-5085
IS - 3
ER -