Olfactory transport: A direct route of delivery of inhaled manganese phosphate to the rat brain

Dorman, DC; Brenneman, KA; Mcelveen, AM; Lynch, SE; Roberts, KC; Wong, BA

HERO ID

35199

Reference Type

Journal Article

Year

2002

Language

English

PMID

12396865

HERO ID 35199
In Press No
Year 2002
Title Olfactory transport: A direct route of delivery of inhaled manganese phosphate to the rat brain
Authors Dorman, DC; Brenneman, KA; Mcelveen, AM; Lynch, SE; Roberts, KC; Wong, BA
Journal Journal of Toxicology and Environmental Health, Part A: Current Issues
Volume 65
Issue 20
Page Numbers 1493-1511
Abstract Experiments examining the dosimetry of inhaled manganese generally focus on pulmonary deposition and subsequent delivery of manganese in arterial blood to the brain. Growing evidence suggests that nasal deposition and transport along olfactory neurons represents another route by which inhaled manganese is delivered to certain regions of the rat brain. The purpose of this study was to evaluate the olfactory uptake and direct brain delivery of inhaled manganese phosphate ((54)MnHPO(4)). Male, 8-wk-old, CD rats with either both nostrils patent or the right nostril occluded underwent a single, 90-min, nose-only exposure to a (54)MnHPO(4) aerosol (0.39 mg (54)Mn/m(3); MMAD 1.68 Ám, "small letter sigma"(g) 1.42). The left and right sides of the nose, olfactory pathway, striatum, cerebellum, and rest of the brain were evaluated immediately after the end of the (54)MnHPO(4) exposure and at 1, 2, 4, 8, and 21 d postexposure with gamma spectrometry and autoradiography. Rats with two patent nostrils had equivalent (54)Mn concentrations on both sides of the nose, olfactory bulb, and striatum, while asymmetrical (54)Mn delivery occurred in rats with one occluded nostril. High levels of (54)Mn activity were observed in the olfactory bulb and tubercle on the same side (i.e., ipsilateral) to the open nostril within 1-2 d following (54)MnHPO(4) exposure, while brain and nose samples on the side ipsilateral to the nostril occlusion had negligible levels of (54)Mn activity. Our results demonstrate that the olfactory route contributes to (54)Mn delivery to the rat olfactory bulb and tubercle. However, this pathway does not significantly contribute to striatal (54)Mn concentrations following a single, short-term inhalation exposure to (54)Mn HPO(4).
Doi 10.1080/00984100290071630
Pmid 12396865
Wosid WOS:000178498100002
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English