Lectin-detectable glycoconjugate profile of the tracheal secretions and epithelial glycocalyx in sheep. Effect of muscarinic stimulation.
Reflex mucus secretion in the airways serves a defense function that includes the binding of bacteria to mucus glycoconjugates thereby preventing bacterial adherence to the epithelium. We therefore compared the lectin-detectable glycoconjugate profile of the epithelial glycocalyx and luminal secretions under baseline conditions and after muscarinic receptor stimulation in the sheep trachea. The sheep were intubated with a double-balloon nasotracheal tube to create a tracheal chamber for collection of secretions. After an initial lavage of the chamber to clear it of secretions, the sheep received an intravenous injection of normal saline, 0.5 mg/kg pilocarpine, or 0.5 mg/kg pilocarpine after pretreatment with 0.2 mg/kg atropine. Tracheal lavage was repeated 2 h later, and the sheep were then killed. An enzyme-linked lectin assay and lectin histochemistry were used to characterize glycoconjugate residues in tracheal secretions and in the apical epithelial glycocalyx, respectively. Eight different lectins were used to detect N-acetyl galactosamine, alpha-galactose, alpha-galactose-N-acetyl galactosamine, beta-galactose, beta-galactose-N-acetyl galactosamine, alpha-fucose, alpha-glucose, alpha-mannose and alpha-(2-3)sialyl residues. After normal saline, reactivity was present for all glycoconjugates in secretions and in the glycocalyx.(ABSTRACT TRUNCATED AT 250 WORDS)
Pulmonary Division, University of Miami, Mount Sinai Medical Center, Miami Beach, Florida 33140.
A T
AT
Mariassy
K T
KT
Toussaint
P
P
Guldimann
W M
WM
Abraham
A
A
Wanner
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006001:Glycoconjugates / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006651:Histocytochemistry; D037102:Lectins / Q000378:metabolism; D010862:Pilocarpine / Q000494:pharmacology; D011134:Polysaccharides / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000502:physiology; D012756:Sheep / Q000378:metabolism*; D013268:Stimulation, Chemical; D014132:Trachea / Q000378:metabolism*
D006001:Glycoconjugates; D006023:Glycoproteins; D037102:Lectins; D011134:Polysaccharides; D011976:Receptors, Muscarinic; D010862:Pilocarpine; D001285:Atropine