The relationship of particle size to olfactory nerve uptake of a non-soluble form of manganese into brain

被引:60
作者
Fechter, LD
Johnson, DL
Lynch, RA
机构
[1] Univ Oklahoma, Hlth Sci Ctr, Coll Pharm, Oklahoma Ctr Toxicol,Dept Occupat & Environm Hlth, Oklahoma City, OK 73190 USA
[2] Univ Oklahoma, Hlth Sci Ctr, Coll Pharm, Oklahoma Ctr Toxicol,Dept Pharmaceut Sci, Oklahoma City, OK 73190 USA
关键词
manganese; inhalation exposure; olfactory nerve transport; rats;
D O I
10.1016/S0161-813X(02)00013-X
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
The essential element, manganese, can produce chronic neuromotor impairment related to basal ganglia (BG) damage when it is presented in excessive quantities. The uptake and elimination patterns of manganese following ingestion have been well studied and, under normal conditions, excretion appears to keep manganese levels under tight. control. Less is known about inhalation exposure, but it has been proposed that the lung might serve as a long-tern reservoir for manganese transport into blood. Recent data suggest that a third route of exposure, transport by the olfactory nerve directly to the brain, might have importance in toxicology since such a route would bypass liver uptake and biliary excretion of manganese. In this study, we sought to determine how particle size and the use of a poorly soluble form of manganese might influence net systemic absorption of manganese dust and the potential role of the olfactory nerve in transport of manganese dioxide. Rats were exposed in nose-only exposure chambers to manganese dioxide (MnO2) aerosols of 1.3 and 18 mum mass median aerodynamic diameter (MMAD). The concentration of aerosols was kept constant at 3 mg/m(3); as Mn. Following 15 days of exposure (fire times per week for 3 weeks), rats were euthanized and tissues harvested for manganese determination carried out by graphite furnace atomic absorption spectroscopy. Small-particle MnO2 exposure resulted in an elevation in olfactory, bulb manganese concentration, presumably through uptake by the olfactory nerve, but the effect was highly variable. While small increases in cortical and neostriatal manganese levels were also observed in these rats, they did not reach statistical significance. By contrast, there was no evidence of olfactory nerve MnO2 uptake in rats receiving the large-particle exposure. (C) 2002 Elsevier Science Inc. All rights reserved.
引用
收藏
页码:177 / 183
页数:7
相关论文
共 23 条
[1]   Direct olfactory transport of inhaled manganese (54MnCl2) to the rat brain:: Toxicokinetic investigations in a unilateral nasal occlusion model [J].
Brenneman, KA ;
Wong, BA ;
Buccellato, MA ;
Costa, ER ;
Gross, EA ;
Dorman, DC .
TOXICOLOGY AND APPLIED PHARMACOLOGY, 2000, 169 (03) :238-248
[2]   DEPENDENCE OF MANGANESE TURNOVER ON INTAKE [J].
BRITTON, AA ;
COTZIAS, GC .
AMERICAN JOURNAL OF PHYSIOLOGY, 1966, 211 (01) :203-+
[3]   MANGANESE IN HEALTH AND DISEASE [J].
COTZIAS, GC .
PHYSIOLOGICAL REVIEWS, 1958, 38 (03) :503-532
[4]   INTERACTIONS BETWEEN MANGANESE AND BRAIN DOPAMINE [J].
COTZIAS, GC ;
MILLER, ST ;
PAPAVASILIOU, PS ;
TANG, LC .
MEDICAL CLINICS OF NORTH AMERICA, 1976, 60 (04) :729-738
[5]   Ultrastructural characteristics and conduction velocity of olfactory receptor neuron axons in the olfactory marker protein-null mouse [J].
Griff, ER ;
Greer, CA ;
Margolis, F ;
Ennis, M ;
Shipley, MT .
BRAIN RESEARCH, 2000, 866 (1-2) :227-236
[6]  
Kim YH, 1999, NEUROTOXICOLOGY, V20, P249
[7]   Dosimetry modeling of inhaled formaldehyde: Comparisons of local flux predictions in the rat, monkey, and human nasal passages [J].
Kimbell, JS ;
Subramaniam, RP ;
Gross, EA ;
Schlosser, PM ;
Morgan, KT .
TOXICOLOGICAL SCIENCES, 2001, 64 (01) :100-110
[8]   Dosimetry modeling of inhaled formaldehyde: Binning nasal flux predictions for quantitative risk assessment [J].
Kimbell, JS ;
Overton, JH ;
Subramaniam, RP ;
Schlosser, PM ;
Morgan, KT ;
Conolly, RB ;
Miller, FJ .
TOXICOLOGICAL SCIENCES, 2001, 64 (01) :111-121
[9]  
MAY KR, 1973, AEROSOL SCI, V4, P235
[10]   PARTICLE INHALABILITY CURVES FOR HUMANS AND SMALL LABORATORY-ANIMALS [J].
MENACHE, MG ;
MILLER, FJ ;
RAABE, OG .
ANNALS OF OCCUPATIONAL HYGIENE, 1995, 39 (03) :317-328