Background: Tissue background autofluorescence induced by standard murine diets containing chlorophyll is a significant problem for fluorescence whole-body imaging. However, as red chlorophyll autofluorescence delineates the gastrointestinal (GI) tract in the abdomen of the mouse, it should be possible to dynamically and non-invasively image intestinal motions. Herein, we non-invasively imaged for the first time intestinal motions, such as peristaltic and segmental motions, without an exogenous imaging agent, using red chlorophyll fluorescence.
Methods: Mice were illuminated with 660-nm light from a laser diode and autofluorescence at 710 nm was acquired dynamically for 5 min with 200-ms exposure time. Fluorescent imaging data were analyzed to generate a three-dimensional spatiotemporal map to quantitate intestinal motions.
Key results: Peristaltic and segmental motions were observed in vivo in mice. Our quantification showed that the frequency and propagation velocity of peristaltic contractile waves in the small intestine were measured to be 28.6 cycles per min and 1.82 ± 0.56 cm s(-1), respectively.
Conclusions & inferences: This simple, but unexplored imaging technique can provide a means to monitor intestinal motility disorders and response to therapeutic agents.
© 2012 Blackwell Publishing Ltd.