DiI Staining of Fine Branches of Bonghan Ducts on Surface of Rat Abdominal Organs

Labeling of rat organ surface Bonghan ducts (BHDs) with DiI. (A) Photomicrograph of abdominal surface showing organ surface Bonghan corpuscles (BHC) and needle (arrowhead) used for DiI injection. The two BHDs (a, b) emanating from BHC (two circles) on organ surface (solid line) and deep abdominal region (dotted line) 12 hours after DiI injection. (B) Fluorescence images of organ surface BHC and attached BHDs (a, b) as shown in A, branches of the BHD (b) (white arrowheads) and blood vessels (asterisks) are shown. Bright signals (white arrows) in lower right part not attributable to DiI fluorescence but to reflection of white light required to locate target object.

A DiI-labeled organ surface BHD in rat deep abdomen. (A) Labeled BHD shown in Figure 1A at 12 hours after DiI injection, branches of BHD (arrowheads) ran parallel to blood vessel (dark lines) and crossed by smaller branches of blood vessels. (B) Enlarged view of boxed region in A showing network-like structures of BHD terminals embedded in membranous tissues (a, b) with nearby fat tissues, branching points (arrows) and blood vessels (asterisks). Images obtained in partially darkened conditions.

Confocal imaging of a BHD containing DiI (red fluorescence; arrows) on rat abdominal organ surface. Optical sections (2.4 μm) from A to D reveal short (solid arrows) and long (open arrows) DiI particles around the BHD sinuses; DNA particles, (green fluorescence) in BHD were stained with acridine orange; sinuses in BHD [3] appeared as dark areas (asterisks) in each panel. The scale bar is 20 μm.