title: A large-scale quantitative EM study on activation of olfactory glands shows no effect of cholinergic agents.
abstract: Little is known about olfactory glands' regulation despite their presumed importance for normal functioning of the cilia of olfactory neurons. The aim of this study was to establish an assay for olfactory gland activation by using large-scale quantitative electron microscopy (EM). In addition we wanted to test the hypothesis that cholinergic drugs activate the olfactory glands, by using our newly established EM assay. In total, over 70 000 secretory gland vesicles were quantified in over 3000 cells. Olfactory gland cell size (40.8 µm2± 2.0 SD), vesicle diameter (812 nm ± 57 SD) and vesicles per cell (21.6 ± 4.2 SD) were also quantified. The vesicle percentage of the cell area varied between 24% and 30%. In a blinded study we found no significant effects of cholinergic agents on parameters of vesicle number or vesicle diameter. Unexpectedly, pilocarpine treatment increased olfactory gland size, probably by inducing cell swelling. In conclusion, we have established a quantitative EM assay for olfactory gland activation and provided new data on basic olfactory gland cell characteristics. By using the EM assay, olfactory glands are shown not to be activated by cholinergic agents, which indicates an alternative regulation pathway or constitutive secretion from olfactory glands.
authors.affiliation: Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Yuchuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital - The Norwegian Radium Hospital, Oslo, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Nina P
authors.initials: NP
authors.lastname: Hessvik
authors.affiliation: Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Niels C
authors.initials: NC
authors.lastname: Danbolt
authors.affiliation: Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway torgeir.holen@medisin.uio.no.
authors.forename: Torgeir
authors.initials: T
authors.lastname: Holen
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D018679:Cholinergic Agonists / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron / Q000379:methods*; D018721:Muscarinic Agonists / Q000494:pharmacology*; D009831:Olfactory Mucosa / Q000187:drug effects* / Q000648:ultrastructure*; D009832:Olfactory Nerve / Q000502:physiology; D010862:Pilocarpine / Q000494:pharmacology*; D012469:Salivary Glands / Q000187:drug effects / Q000502:physiology
chemical_list: D018679:Cholinergic Agonists; D018721:Muscarinic Agonists; D010862:Pilocarpine; D000109:Acetylcholine
keywords: laser microdissection; olfactory glands; olfactory mucosa