In vivo dynamic imaging of intestinal motions using diet-related autofluorescence.
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.


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
This simple, but unexplored imaging technique can provide a means to monitor intestinal motility disorders and response to therapeutic agents.
Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX 77030, USA. sunkuk.kwon@uth.tmc.edu
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Kwon
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Davies-Venn
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EM
Sevick-Muraca
D000818:Animals; D002734:Chlorophyll / Q000737:chemistry*; D004032:Diet; D004063:Digestion; D005453:Fluorescence; D005769:Gastrointestinal Motility / Q000502:physiology*; D007421:Intestine, Small / Q000033:anatomy & histology / Q000502:physiology; D007422:Intestines / Q000033:anatomy & histology* / Q000502:physiology*; D007834:Lasers; D051379:Mice; D010528:Peristalsis; D019265:Spectroscopy, Near-Infrared
D002734:Chlorophyll