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Updated: Jul 18, 2026
10:20
In vitro Measurements of Tracheal Constriction Using Mice
Published on: June 25, 2012
Acetylcholine-induced asynchronous calcium waves in intact human bronchial muscle bundle
Jiazhen M Dai1, Kuo-Hsing Kuo, Joyce M Leo
1The James Hogg iCAPTURE Center for Cardiovascular and Pulmonary Research, University of British Columbia, and St. Paul's Hospital, Room 166, 1081 Burrard Street, Vancouver, BC, V6Z 1Y6 Canada.
American Journal of Respiratory Cell and Molecular Biology
|December 16, 2006
Summary
Acetylcholine triggers asynchronous calcium waves (ACW) in human airway smooth muscle cells, preceding contraction. Force generation depends on recruiting cells for ACW initiation and increasing ACW frequency.
Area of Science:
- Physiology
- Cell Biology
- Pharmacology
Background:
- Calcium ions (Ca2+) are critical for airway smooth muscle (ASM) contraction.
- Agonist-induced Ca2+ signaling is well-understood in animal ASM but not in adult human ASM.
Purpose of the Study:
- To investigate the Ca2+ signal elicited by acetylcholine (ACh) in human ASM cells.
- To correlate Ca2+ signaling with muscle contraction in intact human bronchial muscle strips.
Main Methods:
- Studied Ca2+ signals in intact human bronchial smooth muscle strips from surgical specimens.
- Measured ACh concentration-dependent tissue contraction and Ca2+ wave parameters.
- Utilized pharmacological agents to characterize Ca2+ wave mechanisms.
Main Results:
- ACh induces asynchronous Ca2+ waves (ACW) in individual human ASM cells, preceding force development.
- Graded muscle contraction is achieved by recruiting cells to initiate ACW and increasing ACW frequency.
- ACW involve sarcoplasmic reticulum Ca2+ release (ryanodine-sensitive) and reuptake (SERCA), sustained by extracellular Ca2+ influx.
Conclusions:
- Demonstrates the occurrence of ACW in adult human ASM for the first time.
- Establishes the role of ACW in excitation-contraction coupling in human ASM.
- Highlights the distinct mechanisms of Ca2+ signaling in human ASM compared to animal models.
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