Light and electron microscopic investigation of the lectin-binding patternin the oxyntic gland region of bovine abomasum

For the first time the expression of glycoconjugate residues in the oxyntic gland region of bovine abomasum has been investigated by means of lectin h istochemistry. For light microscopic investigations, a battery of ten lecti ns, Con A, PSA, UEA I, WGA, LEA, SNA, RCA(120), MPA, DBA and SEA was used. For electron microscopic examinations, WGA and RCA120 were utilized. The st aining pattern of the lectins in all exocrine cell types of the oxyntic gla nd region is described. Compared to the results of monogastric species our study reveals some similarities, but just as many differences in the compos ition of glycoconjugate residues in bovine exocrine cell types. Typical for surface mucous cells is the amount of L-fucose, N-acetyl glucosamine resid ues and Gal beta1, 4GlcNAc sequences in the secretory granules. SNA could s erve as a marker for surface mucous cells, because this lectin exclusively stains the plasma membrane and the secretory granules of surface mucous cel ls and the extracellular mucus. L-fucose and N-acetyl glucosamine are typic al for the secretory granules of mucous neck cells. In addition, the secret ory granules show the highest amount of N-acetyl galactosamine residues of all exocrine cells, so that DBA and SEA are recommended as marker lectins f or mucous neck cells. Most lectins strongly stain the intracellular membran e system of oxyntic cells. The cocktail of glycoconjugates in the vicinity of the HCl production site provide protection against chemical injury. In c hief cells only the apical plasma membrane is more or less labeled with all lectins apart from SNA. Specific marker lectins for oxyntic cells or chief cells of the bovine have not been characterized.