Glycoconjugates of the gastric mucosa in cold-treated chipmunks

The effect of hibernation on the morphology and histochemistry of the intestine of the greater mouse-eared bat, Myotis myotis

Seasonal variations in morphometry and histochemistry of the intestine have been examined in the active and hibernating greater mouse-eared bat, Myotis myotis, using histological and histochemical techniques. The results of morphometric analyses indicated that hibernation affected the villus height, villus width, crypt depth and crypt width of the duodenum, jejunum and ileum. Histochemical analysis showed that goblet cells of the small and large intestine contain acidic and neutral mucosubstances. According to the results obtained with Alcian Blue (pH 5.8)/PAS staining, hyaluronic acid is dominant in the goblet cells of the small and large intestine during both the hibernation and active periods. Chondroitin sulfate and dermatan sulfate, which are sulfated GAGs, were dominant, and very little heparan sulfate, heparin and keratan sulfate were present. Moreover, sulfated glycoproteins were also detected in the goblet cells of the small intestine in the active animals. The present study demonstrates that hibernation altered the examined morphometric and histochemical parameters of the intestine.

Seasonal variation in glycoconjugates of the pedal glandular system of the rayed Mediterranean limpet, Patella caerulea (Gastropoda: Patellidae)

Glycoconjugates secreted by the pedal system of the rayed limpet, Patella caerulea, were characterised in situ by histochemical and lectin-histochemical methods in individuals collected around the annual cycle, in November, March, and June. Stainings with periodic acid-Schiff (PAS), Alcian blue pH 2.5 (AB pH 2.5), Alcian blue pH 1.0 (AB pH 1.0), high-iron diamine-Alcian blue pH 2.5 and lectin binding assays with 9 lectins (Con A, WGA, succinylated-WGA, PNA, DBA, SBA, AAA, UEA-I, LTA) were performed. Four secreting cell types were observed in the sole, one in the peripheric region, and two in the sidewall. Glycoconjugate composition varied among cell types and also in one and the same cell type throughout the year. β-Elimination followed by PAS and AB pH 2.5 stainings indicated that most saccharidic chains were O-linked to the protein backbone. Secretion by sole and peripheric region was acidic, carboxylated and/or sulfated, whereas that of the sidewall was neutral. Glucosaminylated and 1,4-fucosylated residuals were predominant in the cell types along the year, 1,2-fucosylated residuals being observed only in the sidewall cells in June. Mannosylated and/or glycosylated residuals were observed in all cells mostly in November. Galactosylated/galactosaminylated residuals were present mostly in the sidewall cells and in the sole subepidermal mucocytes in June. Mannosylated and/or glycosylated residuals in November are probably linked to gonad maturation or to higher locomotion and foraging activity, whereas galactosaminylation in the sole cells and 1,2-fucosylation and glucosaminylation in the sidewall cells in June are linked to a prolonged stationary state, increasing water adsorption to counteract dehydration and/or to modulate microbial interactions.