Olfactory and hepatic changes following inhalation of 3-trifluoromethyl pyridine in rats

Gaskell, Barbara A.; Hext, Paul M.; Pigott, G. H.; Hodge, Michael C.H.; Tinston, D.J.

doi:10.1016/0300-483x(88)90121-7

Cited by 35 publications

(14 citation statements)

References 12 publications

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“…Some nuclei of sustentacular cells (Plate 14) were observed to be approximately two to three times normal size when rats were exposed to 50 ppm 3FMP for 13 weeks (35). This is a personal observation and there does not appear to be any other record of this lesion in the literature.…”

Section: Sustentacular Cell Karyomegalymentioning

confidence: 64%

“…Sensory cells (Plate 13) have been described in rats 35,70, and 157 days after a single 50-ppm exposure of 3FMP (unpublished data) and when rats were exposed to 10 ppm 3FMP 6 hr/day, 5 days/week for 13 weeks (35). It was also seen when hamsters were exposed to furfuraldehyde (22,23).…”

Section: Sensory Cells In the Lamina Propriamentioning

confidence: 88%

“…Frequently, damaged epithelium regenerates, but there is not complete resolution, as it does so in a disorganized fashion with atypical arrangements of the neural elements. Occasionally large bundles of axons are present within the epithelium (42) (Plate 6), and pseudoglandlike structures (35), possibly formed by infolding of the surface epithelium (Plate 7), may also be present. Early stages of regeneration must not be confused with squamous metaplasia that it superficially resembles.…”

Section: Regeneration/repairmentioning

confidence: 99%

“…Early stages of regeneration must not be confused with squamous metaplasia that it superficially resembles. The regenerative process is described in more detail below where studies with 3FMP (35) are reported.…”

Section: Regeneration/repairmentioning

confidence: 99%

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Nonneoplastic Changes in the Olfactory Epithelium. Experimental Studies

Gaskell¹

1990

Environmental Health Perspectives

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Interest in the olfactory mucosa has increased in recent years, since it has been shown to possess a considerable amount of cytochrome P-450-dependent monooxygenase activity and a wide variety of chemicals have been identified as olfactory toxins. Many chemicals induce lesions of a general nature in the olfactory mucosa, i.e., inflammation, degeneration, regeneration, and proliferation, whereas others cause more specific effects.Changes in the olfactory mucosa with reference to chemicals that initiate them are reviewed in this paper. Studies with 3-trifluoromethyl pyridine (3FMP) illustrate some of these general changes and show the importance of examining the olfactory mucosa at early time periods. The earliest damage seen by light microscopy was 6 hr after a single inhalation exposure to 3FMP, and by day 3, early regenerative changes were observed. Changes were seen by electron microscopy 30 min after an oral dose, and the primary site of toxicity appeared to be the Bowman's glands.Although atrophy of nerve bundles in the lamina propria would be the expected consequence of severe necrosis of the sensory cells, this is not always the case. Exposure to irritants such as acetaldehyde, formaldehyde, and dimethylamine results in nerve bundle atrophy, but with chemicals such as 3FMP, 3-methylindole, and 3-methylfuran-which are activated by mixed-function oxidases-the nerve bundles remain intact. Future work, including metabolism studies, will provide more information on the mode of action of these chemicals.

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Section: Sustentacular Cell Karyomegalymentioning

confidence: 64%

Section: Sensory Cells In the Lamina Propriamentioning

confidence: 88%

Section: Regeneration/repairmentioning

confidence: 99%

Section: Regeneration/repairmentioning

confidence: 99%

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Nonneoplastic Changes in the Olfactory Epithelium. Experimental Studies

Gaskell¹

1990

Environmental Health Perspectives

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“…Many studies that evaluate damage to the respiratory tract, specially to the nasal cavity, report inflammation, glandular atrophy, focal hyperplasia of basal cells and squamous metaplasia of the nasal cavity epithelium 1,11,13 . MMA effects on olfactory tissue show a pattern of regeneration during continuous exposure and degeneration that originates disorganization and an apparent resolution 7 , also noticeable in exposure to other chemical agents 6,10 . Only Tansy et al 20,21 (1980, 1979) studied injuries to the tracheal epithelium.…”

Section: Discussionmentioning

confidence: 97%

Assessment of methyl methacrylate vapor toxicity on the rat tracheal epithelium

Parizi¹,

Nai²,

Batalha³

et al. 2005

Braz. oral res.

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ABSTRACT:Methyl methacrylate (MMA) is a monomer that is polymerized into resin by light and heat, producing a clear, resistant, durable and relatively inert plastic material. Because of these characteristics, MMA is largely used in Medicine as bone cement and in Dentistry, in dental braces and prostheses, thus generating continuous interest in its toxicity. Experimental and clinical studies have documented that monomers may cause a wide range of adverse health effects. The most important occupational exposure route of MMA is by inhalation. This study aims to evaluate the toxicity of MMA to the tracheal epithelium, according to the time of exposure. For this purpose, two experimental groups of rats were exposed to MMA by inhalation under poor ventilation: one group (n = 36) was exposed permanently, and the other (n = 36) was exposed during 8 hours per day, without water and food supply during the exposure period. A control group (n = 8) received normal air supply. Twelve animals of each study group were sacrificed after 5, 8 and 10 days of exposure together with two or four control animals. Twenty-nine (80.5%) of the rats continuously exposed to MMA developed inflammation on the tracheal epithelium, as well as 58.33% (n = 21) of those exposed 8 h/day and 87.5% (n = 7) of the control rats. No association was observed between the inflammatory process and MMA exposure; no significant alterations in the tracheal epithelium thickness were observed. Further studies on longer exposure times and analysis of other parameters will have to be conducted to exclude the possibility of tracheal damage by vapors of MMA. DESCRIPTORS: Methylmethacrylate; Trachea; Toxicity. RESUMO:O metil metacrilato (MMA) é um monômero que se polimeriza em resina pela ação da luz e do calor, transformando-se em plástico claro, resistente e durável, relativamente inerte. Por apresentar tais características, o MMA tem sido muito usado na Medicina, como cimento ósseo, e na Odontologia, em aparelhos e próteses dentais, o que tem suscitado interesse na avaliação de sua toxicidade. Estudos experimentais e clínicos têm mostrado que os monômeros podem causar uma gama de efeitos adversos. A principal via de exposição ocupacional ao MMA é a inalatória. Este trabalho visa a avaliar a ação tóxica do MMA sobre o epitélio traqueal em relação ao tempo de exposição. Para isso, dois grupos experimentais de ratos foram expostos ao MMA por inalação, com restrição de ventilação: um grupo (n = 36) foi exposto continuamente, e outro (n = 36) foi exposto durante oito horas diárias, sem água e comida durante o período de exposição. Um grupo controle (n = 8) recebeu ar normal. Doze animais de cada grupo de estudo foram sacrificados com 5, 8 e 10 dias de exposição, junto com dois ou quatro animais do grupo controle. Vinte e nove (80,5%) dos ratos expostos continuamente ao MMA apresentaram inflamação do epitélio traqueal, assim como 58,33% (n = 21) daqueles expostos 8 horas/dia e 87,5% (n = 7) dos controles. Não se observou associação entre o processo inflamatório e a expos...

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