Immunocytochemical localization of pyrazine-binding protein in bovine nasal mucosa

Polyclonal antibodies have been raised against purified bovine pyrazine-binding protein, a protein that binds the odorant 2-isobutyl-3-methoxypyrazine. These antibodies have been utilized in immunocytochemical experiments to localize the pyrazine-binding protein in bovine nasal mucosa. Tissue fragments, macroscopically identified as olfactory and respiratory mucosa, were fixed in Bouin's fluid and embedded in paraffin. Consecutive serial sections were processed for immunofluorescence studies and restained either with haematoxylin-eosin or with periodic acid Schiff-Alcian Blue. In both olfactory and respiratory mucosa, only seromucous tubulo-acinar glands were specifically labelled. These glands are located in the lamina propria underlying typical respiratory epithelium, even in those tissues that are macroscopically defined as olfactory mucosa.