Tamoxifen administration alters gastrointestinal motility in mice

Area of Science:

• Gastroenterology
• Molecular Biology
• Pharmacology

Background:

• Tamoxifen is a key inducer for Cre-estrogen receptor-mediated genomic recombination in transgenic mouse models.
• Its use in lineage tracing and gene function studies is widespread, particularly in assessing gastrointestinal (GI) function.
• Off-target effects of tamoxifen have been noted in various tissues, but its impact on GI motility remained undescribed.

Purpose of the Study:

• To investigate the direct effects of tamoxifen exposure on gastrointestinal motility in wild-type mice.
• To determine if tamoxifen influences key parameters of GI transit and function.

Main Methods:

• Wild-type adult mice were administered tamoxifen.
• Measurements included total GI transit time, gastric emptying rate, small intestinal transit speed, and colonic contractility.

Main Results:

• Tamoxifen treatment resulted in a significant delay in overall GI transit.
• Gastric emptying remained unchanged, while small intestinal transit was accelerated.
• Colonic motility exhibited abnormal patterns following tamoxifen exposure.

Conclusions:

• Tamoxifen administration induces significant alterations in GI motility, affecting transit time and colonic function.
• These findings underscore the necessity of accounting for tamoxifen's prokinetic or inhibitory effects when employing it for Cre-driven studies in the GI tract.
• Researchers using tamoxifen for Cre-mediated recombination in GI studies should consider these motility alterations in their experimental design and interpretation.