title: Glycoconjugate localization with lectin and PA-TCH-SP cytochemistry in rat hypophysis.
abstract: Glycoconjugates were localized by light microscopy with lectin-peroxidase conjugates and by electron microscopy with the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) sequence in immunocytochemically or morphologically identified cell types in rat pituitary. Lectin histochemistry demonstrated sialic acid and glycoconjugates with N-glycosidically linked oligosaccharides in gonadotrophs, thyrotrophs, and corticotrophs. Galactose penultimate to sialic acid was observed mostly in gonadotrophs. The terminal galactose-N-acetylgalactosamine disaccharide was detected in a few gonadotrophs and in a moderate number of mammotrophs. Fucose was localized in only corticotrophs with two fucose-binding lectins and in thyrotrophs with another. Several different monosaccharides were seen in glycoconjugates in melanotrophs and in Herring bodies. Melanotrophs displayed heterogeneous staining with fucose-binding lectins. A small number of nonsecretory cells were also visualized in the pars distalis by virtue of their glycogen content. PA-TCH-SP staining revealed complex carbohydrates in secretory granules and some Golgi cisternae in all types of hormone-producing cells in the pars distalis except for the somatotrophs. Melanotrophs of pars intermedia exhibited stained secretory granules and irregular dense bodies containing a stained meshwork. Corticotrophs of the pars distalis lacked the latter bodies, although they form the same glycoprotein precursor hormone as melanotrophs. Lectin conjugates and the PA-TCH-SP sequence stained some groups of secretion granules in Herring bodies, possibly representing vasopressin-containing granules as well as other cell types in the pars nervosa.
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000032:analysis*; D003366:Cosyntropin / Q000378:metabolism; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D006003:Glycogen / Q000032:analysis / Q000378:metabolism; D006023:Glycoproteins / Q000032:analysis; D006651:Histocytochemistry; D006834:Hydrazines; D007124:Immunoenzyme Techniques; D007202:Indicators and Reagents; D037102:Lectins; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D008543:Melanins / Q000378:metabolism; D008854:Microscopy, Electron; D009844:Oligosaccharides / Q000032:analysis; D010504:Periodic Acid; D010902:Pituitary Gland / Q000032:analysis* / Q000166:cytology; D051381:Rats; D011919:Rats, Inbred Strains; D012836:Silver Proteins; D013972:Thyrotropin / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D002241:Carbohydrates; D006023:Glycoproteins; D006834:Hydrazines; D007202:Indicators and Reagents; D037102:Lectins; D008543:Melanins; D009844:Oligosaccharides; D012836:Silver Proteins; D010504:Periodic Acid; D003366:Cosyntropin; C011368:thiocarbohydrazide; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D006003:Glycogen; C009288:metaperiodate