Research Article

Identification of C-Kit-Positive Interstitial Cells in the Dog Lower Urinary Tract and Relationship with Smooth Muscle and Nerves. Hypotheses for a Likely Pacemaker Role.

Figure 1

(a) Dog jejunum, anti-c-kit immunofluorescence. Interstitial cell bodies can be seen distributed in the smooth muscle wall. (b) Dog bladder, anti-c-kit immunofluorescence. A compressed image obtained by confocal microscopy in a thick tissue section shows strong immunoreactivity in the cytoplasm of an interstitial cell, which is distended among a group of smooth muscle cells. (c) Dog bladder, anti-c-kit immunofluorescence, image obtained as in (b). Subtle c-kit-IF interstitial cells can be seen, elongated among smooth muscle cells and branching with long processes, discernible as immunofluorescent bright dots (arrows). (d) Dog bladder, PAS reaction. Reactivity is present in the cytoplasm of few interstitial cells (arrows), elongated among the smooth muscle bundles. Note the similarity of aspect and localization compared to the c-kit-IF cells shown in (b). When transversally cut, ICs show a roundish shape. Nuclei are unstained. (e) Dog bladder, NADPH-d reaction. Reactivity is present in interstitial cells, running parallel to each other, whose aspect and localization are very similar to the c-kit-IF cells shown in (c). (f) Dog bladder, PAS reaction after diastase digestion. PAS-negativity in a serial section confirms the large accumulation of glycogen granules in the cytoplasm of ICC-like cells shown in (d). Scale bars = 25 μm.
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