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)
Mariassy
A T
AT
Pulmonary Division, University of Miami, Mount Sinai Medical Center, Miami Beach, Florida 33140.
Toussaint
K T
KT
Guldimann
P
P
Abraham
W M
WM
Wanner
A
A
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