Histochemical similarities of mucins produced by Brunner's glands and pyloric glands: A comparative study

Abstract

Mucins of the gastroduodenal junction are secreted by the mucous surface and mucusproducing glandular cells in the stomach, and by goblet cells and Brunner's glands in the duodenum. Developmental studies have demonstrated that Brunner's glands can arise from undifferentiated gastric epithelium and/or intestinal epithelium in the proximal duodenum. The aim of this study was to investigate the carbohydrate composition of mucins from this region and compare it with that of mucins from Brunner's glands to evaluate the probable evolution of mucins from these glands. Toward that end, paraffin sections from 13 mammalian species were stained by classic carbohydrate histochemistry and treated with 13 lectins. In general, the mucous surface cells of the stomach, pyloric glands, duodenal goblet cells, and Brunner's glands secretory epithelium had different lectin-binding patterns. However, the lectin-binding profile of the secretory epithelium of Brunner's glands resembled that of pyloric glands more closely than that of duodenal goblet cells and mucous surface cells of the stomach. Mucins from Brunner's glands and pyloric glands showed a greater terminal carbohydrate residue diversity than those of gastric mucous surface cells or duodenal goblet cells. The lectin-binding profile argues for the evolution of similar mucins from the epithelia of Brunner's glands and pyloric glands. The greater diversity of carbohydrate residues in mucins secreted by Brunner's glands suggests that their mucus is more adaptable. This may explain why Brunner's glands metaplasia rather than goblet cell metaplasia is seen in the mucosa adjacent to chronic intestinal ulcers. Anat Rec Part A 278A:540 -550, 2004. Key words: Brunner's glands; carbohydrate histochemistry; comparative anatomy; gastroduodenal junction; histogenesis; lectin; mucinThe epithelial cells that line the gastrointestinal tract of mammals are protected in part from the somewhat harsh environment of acid, proteolytic enzymes, and abrasives in the lumen by a mucus layer. In the stomach the mucus layer, which is several microns thick, is secreted by both the epithelium lining the gastric mucosa and mucus-producing cells of the gastric glands, while in the duodenum it is secreted by goblet cells and Brunner's glands, which are located in the submucosa. Mucus is a highly hydrated gel that consists of about 95% water, 5% mucins, and minor components, such as electrolytes (Allen, 1981;Neutra and Forstner, 1987). Mucins are high-molecularweight glycoproteins that have gel-forming properties which are highly glycosylated and which in turn are responsible for their protective function.A particular morphological feature of the duodenal submucosa is the presence of Brunner's glands. Brunner's glands are specific to mammals and have been observed in all mammals examined to date (Krause, 1988). They are

The distribution of mucous secreting cells in the gastrointestinal tracts of three small rodents from Saudi Arabia: Acomys dimidiatus , Meriones rex and Meriones libycus

“…In contrast, mixed mucins were the predominant type in the Brunner's glands in the three species under study. The Brunner's glands of both Meriones species indicated a small number of mixed acid (sulfo-and sialo) type mucin secreting cells (Table 5), similar to Schumacher et al (2004) who reported both sulfated and sialomucin secreting goblet cells in the bison, deer, guinea pig, vole and rabbit (Table 5). Both Schumacher et al (2004) and Kotzé and Coetzee (1994) found exclusively acid mucins to be more abundant than neutral mucins in the Brunner's glands of herbivorous species.…”

Lectin Binding Pattern of Gastric Mucosa of Pacific White-Sided Dolphin, Lagenorhynchus obliquidens

“…The different staining patterns of lectins between them are possible to be result from the different kind of secretion between them. The same staining pattern has been observed in human, rat, Japanese macaque, domestic cat, and camel stomachs [2][3][4]23]. In some animals, the bottom portion contains neutral, acidic sulphated, and acidic carboxylated mucins [23].…”

“…Although GSL-I, DBA, SBA and RCA-I all recognize the N-acetylgalactosamine (GalNAc) residue, SBA and RCA-I labelled the basal layer of the cornified stratified squamous epithelium, but GSL-I and DBA did not. This difference in binding specificity was not surprising, given that lectin reactivity is affected by the stage of cell migration [23]. The superficial layer cells differentiate from the basal cells during migration to the luminal surface, where reactivity with the lectins may change [17].…”

The unfolded protein response is activated in Helicobacter-induced gastric carcinogenesis in a non-cell autonomous manner

“…This region of the gastric gland also stained positively with AB at pH 2.5, consistent with previous reports in rodents but not in humans. 26 An intact UPR is required for normal innate 27,28 and adaptive immunity in metazoans and activation of innate immunity induces the UPR. 29 High constitutive expression of Hspa5 in the normal gastric mucosa might, therefore, be associated with the indigenous gastric microflora of conventionally raised coprophagic mice.…”