Distribution and changes of glycoconjugates in rat colonic mucosa during development

Abstract

A study was made of the modifications of glycoconjugates in rat colonic mucosa during development. Sections of the caecum, and proximal and distal portions of the colon from Sprague Dawley rats at different stages of development (embryos, fetuses, suckling, weaning and adult rats) were examined. The sections were incubated with a battery of eight fluoresceinated lectins: DBA, SBA, WGA, LFA, PNA, GS-I, UEA-I and Con A. Some sections were treated with neuraminidase, and others were submitted to sequential saponification-neuraminidase treatment prior to incubation with the lectin (WGA, PNA or LFA). The intensity of the fluorescence was evaluated and graded from absent (-) to very positive (4+). Gradual and progressive changes were seen in colonic glycoconjugates during development. These changes revealed a unique developmental pattern for each lectin, which was independent for each cellular compartment (goblet cells, luminal surface and supranuclear region). Local and regional differences, observed between the different colonic sections, were already present from early stages of development. Moreover, our study showed that for several glycoconjugates, the differentiation process in colonic mucosa began in the distal region and continued through to the proximal region, the former being the first to reach the adult pattern. In the caecum, some lectins maintained a fetal pattern throughout all the periods of development up to the adult stage.

A Histochemical Study on Glycoconjugates in Epithelial Cells in the Distal Colonic Mucosa of Adult and Developing Mice.

“…It has been demonstrated by a variety of carbohydrate stainings that goblet cells of the distal colon elaborate sulfated glycoconjugates in different animals (SHEAHAN and JERVIS, 1976;PODDAR and JACOB, 1981;TSUYAMA et al, 1983). The reaction of non-sulfonic acidic groups of glycoconjugates is obscured by the strong reaction of sulf onic groups in these carbohydrate stainings, and the presence of sialyl residues in goblet cells has been revealed by lectin histochemistry (FREEMAN et al, 1980, CALDERO et al,1988; the present study). Different results have been reported on the binding of UEA-I in goblet cells of the distal colon.…”

“…Different results have been reported on the binding of UEA-I in goblet cells of the distal colon. In rats, which have been the most extensively studied, some authors have reported negative reactions (ESSNER et al, 1978;TSUYAMA et al,1983;COLONY and STEELY, 1987), whereas others have noted variable reactivities depending on the sites of the cells or ontogenetic stages (FREEMAN et al, 1980;CALDERO et al, 1988). In the mouse distal colon, goblet cells bind UEA-I and are thus considered to have fucosylated glycoconjugates (BOLAND and AHNEN,1985; the present study).…”

“…To our knowledge, the only histochemical study to distinguish vacuolated cells from goblet cells has been carried out in the colon of adult rats, where staining patterns of mucins of these two types of cells were apparently different from each other (TSUYAMA et al, 1983). Although many histochemical studies on glycoconjugates during the course of colonic development have been carried out, no special statement has been made as to vacuolated cells (ESSNER et al,1978;FREEMAN et al, 1980;PODDAR and JACOB, 1981;BOLAND and AHNEN, 1985;COLONY and STEELY, 1987;PONGCHAIRERKS et a1., 1987;CALDERO et al, 1988).…”

N- andO-linked Oligosaccharides in the Secretory Granules of Rat Paneth Cells: An Ultrastructural Cytochemical Study

“…Oligosaccharide composition of the glycoproteins of the intestinal epithelial cells has been investigated by lectin histochemistry, with special attention to goblet and absorptive cells (Brinck et al 1995;Madrid et al 1989;Calderó et al 1988;Skutelsky et al 1987;Etzler and Branstrator 1974). Although Paneth cells share ultrastructural characteristics typical of serous cells (large apical secretory granules and abundant basal rough endoplasmic reticulum), early histochemical studies revealed that they contain a mucoid material (Herzog 1937).…”

Changes in Lectin-Binding Patterns during Late Fetal Development of the Rat Colon

“…There is lack of con cordance among reports on the lectin-binding patterns during morphogenesis of the rodent colon, as many of the lectin studies on the developing colon considered the stages of late fetal development as a single phase. Although profound differences were demonstrated between prenatal and postnatal glycoprotein expression [11,12], critical changes during the immediate prenatal period have been overlooked. We needed to know more about events during late fetal development of the mam malian colon, prior to the neonatal phase of cell differen tiation which is our main interest.…”