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Updated: May 11, 2026
07:54
Cholesterol Efflux Assay
Published on: March 6, 2012
Excess membrane cholesterol alters human gallbladder muscle contractility and membrane fluidity
1Department of Medicine, Rhode Island Hospital and Brown University School of Medicine, Providence, Rhode Island, USA.
Gastroenterology
|February 25, 1999
Summary
Gallstones alter gallbladder muscle function by increasing membrane cholesterol, reducing fluidity, and impairing contraction. Removing excess cholesterol restores normal muscle contractility.
Area of Science:
- Gastroenterology
- Cell Biology
- Biochemistry
Background:
- Gallstones are common, and their impact on gallbladder muscle function is not fully understood.
- Cholesterol gallstones are the most prevalent type, suggesting a potential role for cholesterol metabolism in disease pathogenesis.
Purpose of the Study:
- To investigate the relationship between muscle contractility, plasma membrane cholesterol, and fluidity in human gallbladders with gallstones.
- To determine if correcting plasma membrane abnormalities can restore normal gallbladder muscle function.
Main Methods:
- Human gallbladder muscle cells were isolated to measure contraction.
- Plasma membranes were purified to quantify cholesterol content and cholesterol/phospholipid mole ratio.
- Membrane fluidity was assessed using fluorescence polarization.
Main Results:
- Gallbladder muscle contractility was significantly reduced in cholesterol gallstones compared to pigment gallstones.
- Cholesterol gallstones exhibited higher membrane cholesterol content and cholesterol/phospholipid mole ratio, indicating decreased membrane fluidity.
- Incubation with cholesterol-free liposomes normalized muscle contraction, membrane composition, and fluidity.
Conclusions:
- Cholesterol gallstones are associated with increased membrane cholesterol and reduced fluidity in gallbladder muscle, leading to impaired contractility.
- These membrane abnormalities and functional deficits are reversible upon cholesterol removal.
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