Figure 3

Up-regulation of SP gene expression in regenerative mucosa after induced antral ulceration in the rat. A, In situ hybridization using antisense rat SP riboprobe, darkfield view, of normal rat gastric antrum. mRNA expression is restricted to the region of the gastric gland between the base and midgland. L, lumen; original magnification, ×100. B, In situ hybridization to rat SP in regenerative (day 12) epithelium, darkfield view, showing increase in both signal intensity and distribution of SP mRNA, contrasting with tissue from the opposite antral wall. Original magnification, ×100. C, Brightfield view of B, showing that the tissue with increased SP mRNA expression consists of elongated glands with SP mRNA expression along the length of these glands, in contrast to the glands of normal height on the opposite gastric wall. L, lumen; original magnification, ×100. D, SP immunohistochemistry in regenerative (day 12) gastric epithelium. SP immunoreactivity is present along the length of the elongated gastric glands (black arrow). Tortuous and elongated glands with cystic dilation, also showing SP immunoreactivity, are seen to the right of the field (white arrow). Original magnification, ×200. E, proliferating cell nuclear antigen (PCNA) immunohistochemistry in a serial section corresponding to D. Arrowheads mark dilated glands with frequent PCNA-immunoreactive nuclei. F, Mucin histochemistry (periodic acid-Schiff (PAS)/alcian blue) in a serial section corresponding to D.