Tamoxifen administration alters gastrointestinal motility in mice

Abstract

Background Tamoxifen is widely used for Cre‐estrogen receptor‐mediated genomic recombination in transgenic mouse models to mark cells for lineage tracing and to study gene function. However, recent studies have highlighted off‐target effects of tamoxifen in various tissues and cell types when used for induction of Cre recombination. Despite the widespread use of these transgenic Cre models to assess gastrointestinal (GI) function, the effect of tamoxifen exposure on GI motility has not been described. Methods We examined the effects of tamoxifen on GI motility by measuring total GI transit, gastric emptying, small intestinal transit, and colonic contractility in wild‐type adult mice. Key Results We observed a significant delay in total GI transit in tamoxifen‐treated mice, with unaltered gastric emptying, accelerated small intestinal transit, and abnormal colonic motility. Conclusion Our findings highlight the importance of considering GI motility alterations induced by tamoxifen when designing protocols that utilize tamoxifen as a Cre‐driver for studying GI function.

An Optogenetics-based Approach to Regulate Colonic Contractions by Modulating the Activity of the Interstitial Cells of Cajal in Mice

“…A recent study showed that TAM administration induced changes in contractility in isolated colons in mice, especially an increase in the number of short contractions. 33 TAM was used in both groups in our study. However, we did not compare LFHA contractions in animals that were treated with TAM and that were untreated, as both Kit-ChR2(+) and Kit-ChR2(–) mice received the same TAM injection, which ensured comparable results in isometric force recordings between the 2 groups.…”

Enteric glia as friends and foes of the intestinal epithelial barrier function

“…This indicates that tamoxifen co-administration via chow can exacerbate tissue damage and increase gut dysfunction. Indeed, tamoxifen administration in mice and humans showed altered gastrointestinal motility ( 45 ) and tamoxifen-induced intestinal epithelial barrier damage ( 46 ), respectively. Therefore, tamoxifen administration should be controlled for the off-target effects of tamoxifen treatment in GI.…”