RESUMEN

We analyzed 4,352 participant- and staff-collected respiratory specimens from 2,796 subjects in the Oregon Child Absenteeism due to Respiratory Disease Study. Trained staff collected oropharyngeal specimens from school-aged children with acute respiratory illness while household participants of all ages collected their own midturbinate nasal specimens in year one and anterior nasal specimens in year two. Human ribonuclease P levels were measured using RT-PCR for all staff- and participant-collected specimens to determine adequacy, defined as Cycle threshold less than 38. Overall, staff- and participant-collected specimens were 99.9% and 96.4% adequate, respectively. Participant-collected midturbinate specimens were 95.2% adequate in year one, increasing to 97.2% in year two with anterior nasal collection. The mean human ribonuclease P Cycle threshold for participant-collected specimens was 31.18 in year one and 28.48 in year two. The results from this study suggest that community-based participant collection of respiratory specimens is comparable to staff-collected oropharyngeal specimens, is feasible, and may be optimal with anterior nasal collection.

Asunto(s)

Cavidad Nasal/enzimología , Orofaringe/enzimología , Ribonucleasa P/genética , Ribonucleasa P/aislamiento & purificación , Manejo de Especímenes/métodos , Adolescente , Adulto , Niño , Preescolar , Servicios de Salud Comunitaria , Femenino , Humanos , Gripe Humana/diagnóstico , Gripe Humana/virología , Masculino , Persona de Mediana Edad , Cavidad Nasal/virología , Orofaringe/virología , Participación del Paciente/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Manejo de Especímenes/instrumentación , Wisconsin , Adulto Joven

RESUMEN

BACKGROUND: Intranasal agents play a critical role in the management of sinonasal disorders. There are ongoing efforts to develop new intranasal medications to combat sinonasal disease. Some intranasal agents, however, can have cytotoxic effects on human sinonasal tissue. In order to facilitate safe drug discovery, we developed a simple and reliable in vitro screening assay using human sinonasal explants to measure the cytotoxic profiles of intranasal agents. METHODS: We obtained sinonasal tissues from several regions of the nasal cavity from 12 patients undergoing endoscopic sinonasal surgery. These tissues were cultured on polytetrafluoroethylene membrane in serum-free growth medium. We determined the biochemical properties of these explants by measuring extracellular lactate dehydrogenase (LDH) levels and performing histological analyses over a period of 1 to 2 weeks. We then examined the cytotoxic profiles of 13 intranasal agents by measuring extracellular LDH levels using the human sinonasal explant system. RESULTS: Sinonasal explants exhibited a rapid reduction in extracellular LDH levels indicating stabilization in the culture environment within 2 days. Histological analysis showed maintenance of good cellular architecture for up to 2 weeks. The explants displayed intact epithelium and expressed ßIII-tubulin and Ki-67. Of the 13 tested intranasal agents, 1% zinc sulfate (ZnSO(4) ), 5% ZnSO(4) , and Zicam application were cytotoxic. CONCLUSION: Based on the unique biochemical properties of the human nasal explant culture system, we developed a simple and reliable in vitro screening assay to determine the cytotoxic profiles of various intranasal agents by examining extracellular LDH levels and histopathology.

Asunto(s)

Descubrimiento de Drogas/métodos , L-Lactato Deshidrogenasa/metabolismo , Cavidad Nasal/enzimología , Fármacos del Sistema Respiratorio/toxicidad , Biomarcadores/metabolismo , Células Cultivadas , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Pruebas de Enzimas/métodos , Humanos , Enfermedades de los Senos Paranasales/tratamiento farmacológico , Pruebas de Toxicidad/métodos

RESUMEN

Ganglioglioma is a tumor containing both astrocytic and neuronal components. It may occur any where in the central nervous system and spinal cord but is only encountered rarely. Nasal glial heterotopia (also known as ''nasal glioma''), is a rare developmental abnormality seen in a wide age group. Gangliogliomas may also manifest as a nasal glial heterotopia, and neurogenic tumors should be considered in the presence of a nasal mass. In this article, we present a case of ganglioglioma located in the right-nasal cavity. The mass was excised totally through an endoscopic approach. The ganglioglioma developed on a nasal glial heterotopia base. To our knowledge, a ganglioglioma arising from the nasal cavity has not been described previously in the literature.

Asunto(s)

Ganglioglioma/cirugía , Neoplasias Nasales/cirugía , Endoscopía , Femenino , Ganglioglioma/enzimología , Ganglioglioma/patología , Humanos , Cavidad Nasal/enzimología , Cavidad Nasal/cirugía , Conducto Nasolagrimal/cirugía , Neoplasias Nasales/enzimología , Neoplasias Nasales/patología , Fosfopiruvato Hidratasa/análisis , Proteínas S100/análisis , Adulto Joven

RESUMEN

Immunolocalization of the secretory form of carbonic anhydrase isoenzyme, CA-VI were studied using a specific canine CA-VI antiserum, and CA-VI mRNA signals were also investigated using the reverse-transcriptase polymerase chain reaction (RT-PCR) in canine nasal mucosal epithelia and glands. Immunoreactivity to CA-VI was positive throughout the mucosal epithelial cells and in the cytoplasm of serous acinar and ductal epithelial cells of the nasal mucosa and glands, including the vestibule of the nose, but the mucous acinar cells of the glands were immunonegative. We detected CA-VI gene transcripts in the same regions as the CA-VI immunoreactivity. The physiological roles of CA-VI in the nasal mucosal epithelium and glands might maintain bicarbonate levels in nasal secretions and protect the mucosa against acid.

Asunto(s)

Anhidrasas Carbónicas/biosíntesis , Perros/metabolismo , Cavidad Nasal/enzimología , Animales , Anhidrasas Carbónicas/genética , Perros/genética , Expresión Génica , Inmunohistoquímica/veterinaria , Mucosa Nasal/enzimología , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria

RESUMEN

Esthesioneuroblastoma (ENB) differs from adrenal neuroblastomas in its histopathologic and biologic characteristics. Hyams grading and Kadish staging have shown correlation with survival. Scant data are available on proliferation indices and prognosis. We retrospectively reviewed the clinicopathologic characteristics of ENB. Both Kadish and UCLA staging systems were used. Hyams grading was simplified into low and high grade. DNA topoisomerase II alpha labeling index (T2alpha LI) was obtained in 8 cases using immunohistochemistry. Of the 19 cases studied, 14 were males and 5 females. Age range was 2 to 62 years (average 27 years). The mass primarily involved the nose in 12 (63%) and paranasal sinuses in 7 cases (37%). Patients presented with nose block in 19 (100%), epistaxis in 10 (53%), proptosis in 9 (47%) and loss of vision in 6 cases (32%). Bony involvement was seen in 7 cases (37%), and intracranial spread in one case (5%). Thirteen (68%) were low-grade tumors and 6 were (32%) high-grade. There was no statistically significant difference between the low- and high-grade ENB in age (years) (p=0.2882), duration of symptoms (months) (p=0.5636), and either in the Kadish (p=0.5456) or the UCLA staging system (p=0.7771). The difference in DNA topoisomerase alpha labeling index between the low- and highgrade ENB (medians: 10.4 and 22.3, respectively) was not statistically significant (p=0.0714), but it was suggestive of a positive association. The results of this study should be interpreted with caution, because of the limited sample size. Three cases recurred locally, one each stage A, B and C, but all low-grade. This preliminary study suggests the need to combine a simplified histologic grading with accurate staging in a reasonable attempt to assess local progression in esthesioneuroblastoma. Larger studies may clarify the role of T2alpha LI in improving histologic grading.

Asunto(s)

Antígenos de Neoplasias/fisiología , ADN-Topoisomerasas de Tipo II/fisiología , Proteínas de Unión al ADN/fisiología , Estesioneuroblastoma Olfatorio/enzimología , Cavidad Nasal/enzimología , Neoplasias Nasales/enzimología , Adolescente , Adulto , Antígenos de Neoplasias/genética , Proliferación Celular , ADN-Topoisomerasas de Tipo II/genética , Proteínas de Unión al ADN/genética , Estesioneuroblastoma Olfatorio/patología , Femenino , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Cavidad Nasal/patología , Estadificación de Neoplasias , Neoplasias Nasales/patología , Estudios Retrospectivos

RESUMEN

INTRODUCTION: The first embryonic part of the nasal cavity is the primary nasal duct, beginning with the olfactory placode and ending with the oronasal membrane. Aim of this study was to investigate the cellular processes (apoptosis, proliferation) being responsible for development and opening of the primary nasal duct. MATERIAL AND METHODS: In this study developmental processes in at least three regions of the primary nasal duct (opening, middle, end) were examined by sectioning 38 rat fetuses on day 13.5 after conception. Apoptotic cells were detected by active caspase-3 antibodies and proliferating cells were examined by Ki-67 antibodies. RESULTS: Multiple apoptotic events were diagnosed on the basis and proliferative cells on the top of this duct. CONCLUSION: Apoptosis and proliferation play an important role in the process of opening the bottom of the primary nasal duct and for development of the nasal septum, philtrum as well as the primary palate. Mesenchymal proliferation seems to play a minor role in the process of opening the primary nasal duct.

Asunto(s)

Apoptosis/fisiología , Proliferación Celular , Cavidad Nasal/embriología , Animales , Caspasa 3/análisis , Femenino , Antígeno Ki-67/análisis , Cavidad Nasal/enzimología , Embarazo , Ratas

RESUMEN

CYP4B1 is highly expressed in rat nasal respiratory mucosa, and to a lesser extent in olfactory mucosa. Examination of high-power photomicrographs suggests that CYP4B1 may be a secreted protein, based on the fact that immunoreactivity appears to be present in the lumens of ducts of Bowman's glands (rather than intracellular localization, as we observed with an antibody recognizing CYP2F4) and in secretory granules in respiratory mucosa. Furthermore, anti-CYP4B1 immunoreactivity is present on the surface of both respiratory and olfactory mucosa. We used SignalP 3.0 analysis to ascertain the likelihood that rat CYP4B1 is a secreted protein. While this analysis does not suggest that rat CYP4B1 is a secreted protein, several other cytochrome P450 enzymes were predicted to be secreted proteins. The observation that multiple human cytochrome P450s appear to be secreted proteins helps to explain the appearance of anti-cytochrome P450 antigens in cases of human autoimmune liver diseases.

Asunto(s)

Hidrocarburo de Aril Hidroxilasas/metabolismo , Cavidad Nasal/enzimología , Animales , Humanos , Mucosa Nasal/citología , Transporte de Proteínas , Ratas , Ratas Sprague-Dawley

RESUMEN

A variety of chemicals induce site-specific lesions in the rodent nasal cavity. In order to explore the reasons for this site-selectivity, methodology for (a) creation of a 3-dimensional (3D) model of a rat nasal cavity, and (b) mapping of semiquantitative data onto the model has been developed. The head of a rat was fixed, decalcified, step-sectioned (every 100 microm) and stained with hematoxylin and eosin. Digital images of the sections were optically captured, and a KS400 image analysis system (Imaging Associates, Thame, Oxford, UK), attached to a standard personal computer, was used to align adjacent images and reconstruct the series in 3D. The final model was anatomically correct, and could be rotated in any plane and manipulated to display individual internal structures. The spatial localization of a glutathione S-transferase (rGSTM1, previously known as GST 3-3) within this model was investigated using immunohistochemistry. Step sections (every 400 microm) were stained, analyzed by imaging densitometry, and the results for the stained regions within the nasal cavity divided into 4 grades representing high to low expression of rGSTM1. The data was mapped onto the 3D model and showed that the highest expression of this enzyme was in the central regions of the nasal cavity at the transition between respiratory and olfactory epithelia. This methodology will allow investigation of the relationship between the in situ localization of bioactivating and detoxifying enzyme systems and the site-specificity of nasal lesions.

Asunto(s)

Glutatión Transferasa/metabolismo , Imagenología Tridimensional/métodos , Modelos Animales , Cavidad Nasal/anatomía & histología , Animales , Inmunohistoquímica , Técnicas In Vitro , Masculino , Cavidad Nasal/enzimología , Ratas , Ratas Wistar

RESUMEN

OBJECTIVES: To clarify the localization of cyclooxygenase (COX)-1 and -2 in the nasal cavity of guinea pigs and ascertain their physiological roles. MATERIAL AND METHODS: The distribution of the enzymes was investigated using immunohistochemistry. RESULTS: Immunoreactivities for COX-1 and -2 were limited to the nasal glands, and no expression was noted in the surrounding vascular endothelial cells, olfactory glands, respiratory epithelium, olfactory epithelium, submucosal tissue or nerves. To confirm the specificity of the reaction, the kidneys of the same animals were prepared as positive controls. The results demonstrated localization of COX-1 and -2 in uriniferous tubules. CONCLUSION: Our findings suggest that COX is involved in the secretion of nasal discharge from the nasal glands and that prostaglandins in the nasal discharge are probably secreted directly from the nasal glands.

Asunto(s)

Isoenzimas/metabolismo , Cavidad Nasal/enzimología , Cavidad Nasal/patología , Prostaglandina-Endoperóxido Sintasas/metabolismo , Animales , Ciclooxigenasa 1 , Ciclooxigenasa 2 , Femenino , Cobayas , Inmunohistoquímica , Isoenzimas/análisis , Modelos Animales , Mucosa Nasal/enzimología , Mucosa Nasal/patología , Técnicas de Cultivo de Órganos , Prostaglandina-Endoperóxido Sintasas/análisis , Valores de Referencia , Sensibilidad y Especificidad

RESUMEN

Despite extensive interest in the rodent nasal cavity as a target organ for toxicity, there is very limited information regarding nasal defenses against oxidative stress and xenobiotic-derived oxidants. Using immunohistochemistry, we have examined the distribution of Cu,Zn and Mn superoxide dismutase (SOD), catalase, glutathione (GSH) peroxidase, and DT-diaphorase in rat nasal tissues. In addition, we have determined the concentrations of ascorbate and alpha-tocopherol and the activities of SOD (combined Cu,Zn and Mn forms), catalase, GSH peroxidase, GSH reductase, and DT-diaphorase in nasal respiratory epithelium (RE), olfactory epithelium (OE), and in lung. Immunohistochemistry demonstrated that all four enzymes were similarly distributed, with the greatest staining intensity in dorsal-medial regions of the nasal cavity. In respiratory epithelium, ciliated columnar cells and subepithelial glands stained positively, while in olfactory tissue the enzymes were detected in the sustentacular cells and Bowman's glands. With the exception of SOD, enzyme activities were higher in RE than OE, while concentrations of ascorbate and alpha-tocopherol were higher in OE than RE. With the exception of catalase, nasal activities were either higher than or comparable to those of the lung. Thus, the rat nasal cavity appears to be well protected against oxidative damage.

Asunto(s)

Antioxidantes/metabolismo , Catalasa/metabolismo , Glutatión Peroxidasa/metabolismo , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Cavidad Nasal/enzimología , Superóxido Dismutasa/metabolismo , Animales , Ácido Ascórbico/metabolismo , Células Epiteliales/enzimología , Células Epiteliales/metabolismo , Técnicas para Inmunoenzimas , Masculino , Cavidad Nasal/anatomía & histología , Mucosa Olfatoria/enzimología , Mucosa Olfatoria/metabolismo , Oxidación-Reducción , Estrés Oxidativo , Ratas , Ratas Wistar , alfa-Tocoferol/metabolismo

RESUMEN

NADPH diaphorase histochemical protocols were optimized for the histochemical labeling of olfactory receptor neurons (ORNs) in the nasal cavity and their axon terminals in glomeruli of the main olfactory bulb (MOB) in the Syrian hamster. This labeling was then used to map and quantify the spatial distribution of ORNs and their central projections. Diaphorase-positive ORNs were found to be rhinotopically restricted to dorsal-medially situated segments of sensory mucosa associated with central air channels in the nose, together constituting about 25% of the total receptor sheet. This topography closely resembles the zonal expression patterns of putative odorant receptor genes and cell surface glycoconjugates in the nose. Moreover, the projections of ORNs in the diaphorase-positive dorsal/central zone were found to expand onto the entire dorsal half of the MOB, consistent with spatial patterns discerned in retrograde tract-tracing studies. These boundaries indicate that dorsal/central zone ORNs project to a disproportionately larger region of the MOB than do those in the more ventral/peripheral zones. The demonstration of NADPH diaphorase activity in ORNs is inconsistent with the expression of the best-known NADPH-dependent enzymes, such as nitric oxide synthase (neuronal and endothelial isoforms) and NADPH cytochrome P450 oxidoreductase. Understanding the spatial patterning of histochemical labeling in ORNs should facilitate the biochemical identification of this diaphorase.

Asunto(s)

NADPH Deshidrogenasa/metabolismo , Bulbo Olfatorio/anatomía & histología , Vías Olfatorias/anatomía & histología , Neuronas Receptoras Olfatorias/anatomía & histología , Animales , Axones/enzimología , Cricetinae , Femenino , Inmunohistoquímica , Masculino , Mesocricetus , Cavidad Nasal/enzimología , Cavidad Nasal/inervación , Bulbo Olfatorio/enzimología , Vías Olfatorias/enzimología , Neuronas Receptoras Olfatorias/enzimología

RESUMEN

We examined the histochemical localization of carbonic anhydrase (CA) in Bowman's glands by light and electron microscopy. Neither CAI nor CAII was detected immunohistochemically in the duct cells. However, by enzyme histochemistry the duct cells revealed electron-dense precipitates demonstrative of CA in the microvilli and intercellular digitations. The reaction product was also noted in small vesicles in the cytoplasm of duct cells. In cells of the acini, the well-developed short microvilli, basolateral cell membrane, and mitochondria along the basolateral membrane showed strong deposits indicating CA activity. Dense reaction product of CA was also detected in a small core within the electron-lucent granules of the secretory cells, although CAI and CAII were not detected by immunostaining in the secretory granules. Although the functional significance of CA in Bowman's glands is obscure, the enzyme may play a role in regulation of pH and ion balance in the mucous layer covering the olfactory epithelium. The presence of CA activity in the ducts suggests that these structures are not simple tubes serving as a conduit for secretory substances but participate in modifying the luminal content by secreting CA. (J Histochem Cytochem 47:1525-1531, 1999)

Asunto(s)

Anhidrasas Carbónicas/metabolismo , Cavidad Nasal/enzimología , Animales , Femenino , Cobayas , Técnicas para Inmunoenzimas , Microscopía Inmunoelectrónica , Membrana Mucosa/citología , Membrana Mucosa/enzimología , Mucosa Olfatoria/enzimología

RESUMEN

The objectives of this study were to determine: (1) the frequency and distribution of carbonic anhydrase (CA) activity in the bullfrog nasal cavities, and (2) whether inhibition of nasal CA affects the olfactory receptor response to CO2 or other odorants. It was found, using Hansson's staining technique, that some olfactory receptor neurons exhibited CA activity and that these CA-positive receptors were distributed throughout the nasal cavity with peak densities in the dorsal and ventral sensory epithelial regions. To test for the role of CA in olfactory transduction, electro-olfacto-grams (EOGs) were recorded from the surface of the ventral sensory epithelium in response to 2-s pulses of 5% CO2 and amyl acetate before and after topical CA inhibition with acetazolamide (10(-3) mol.l-1). In 52 bullfrogs, 1222 sites on the ventral epithelium were tested resulting in 23 locations that exhibited a response to 5% CO2. Inhibition of CA caused an immediate 65% reduction in the EOG response to CO2 while the response to amyl acetate was not affected. These results, along with the histochemical localization of CA in some olfactory receptor neurons, indicate that CA plays a role in the detection of CO2 in frog olfactory neurons and that only a small population of olfactory receptor neurons are CO2 sensitive.

Asunto(s)

Dióxido de Carbono/fisiología , Anhidrasas Carbónicas/metabolismo , Células Quimiorreceptoras/fisiología , Neuronas Receptoras Olfatorias/enzimología , Acetazolamida/farmacología , Animales , Inhibidores de Anhidrasa Carbónica/farmacología , Electrooculografía , Electrofisiología , Histocitoquímica , Cavidad Nasal/enzimología , Cavidad Nasal/inervación , Rana catesbeiana , Transducción de Señal/fisiología

RESUMEN

High levels of xenobiotic-metabolizing enzymes occur in the nasal mucosa of all species studied. In certain species, including rats and rabbits, unique enzymes are present in the nasal mucosa. The function of these enzymes is not well understood, but it is thought that they play a role in protecting the lungs from toxicity of inhalants. The observation that several nasal xenobiotic-metabolizing enzymes accept odorants as substrates may indicate that these enzymes also play a role in the olfactory process. Xenobiotic-metabolizing enzymes were found in the nasal cavity around 15 years ago. Since that time, much has been learned about the nature of the enzymes and the substrates they accept. In the present review, this information is summarized with special attention to species differences in xenobiotic-metabolizing enzymes of the nasal cavity. Such differences may be important in interpreting the results of toxicity assays in animals because rodents are apparently more susceptible to nasal toxicity after exposure to inhalants than are humans.

Asunto(s)

Cavidad Nasal/enzimología , Mucosa Nasal/enzimología , Xenobióticos/metabolismo , Administración por Inhalación , Animales , Sistema Enzimático del Citocromo P-450/metabolismo , Inducción Enzimática , Inhibidores Enzimáticos/farmacología , Humanos , Especificidad de Órganos , Conejos , Ratas , Especificidad de la Especie

RESUMEN

Macrophage-stimulating protein (MSP) is an 80-kD serum protein with homology to hepatocyte growth factor (HGF). Its receptor, RON tyrosine kinase, is a new member of the HGF receptor family. The MSP-RON signaling pathway has been implicated in the functional regulation of mononuclear phagocytes. However, the function of this pathway in other types of cells has not been elucidated. Here we show that in contrast to the HGF receptor, which was expressed at the basolateral surface, RON was localized at the apical surface of ciliated epithelia in the airways and oviduct. In addition, MSP was found in the bronchoalveolar space at biologically significant concentrations. MSP bound to RON on normal human bronchial epithelial cells with a high affinity (Kd = 0.5 nM) and induced autophosphorylation of RON. Activation of RON by MSP led to a significant increase in ciliary beat frequency of human nasal cilia. These findings indicate that the ciliated epithelium of the mucociliary transport apparatus is a novel target of MSP. Ciliary motility is critical for mucociliary transport. Our findings suggest that the MSP-RON signaling pathway is a novel regulatory system of mucociliary function and might be involved in the host defense and fertilization.

Asunto(s)

Sustancias de Crecimiento/fisiología , Factor de Crecimiento de Hepatocito , Macrófagos Alveolares/enzimología , Macrófagos Alveolares/fisiología , Proteínas Proto-Oncogénicas , Proteínas Tirosina Quinasas Receptoras/fisiología , Receptores de Superficie Celular/fisiología , Animales , Bronquios/enzimología , Bronquios/metabolismo , Bronquios/ultraestructura , Líquido del Lavado Bronquioalveolar/química , Cilios/enzimología , Cilios/fisiología , Cilios/ultraestructura , Epitelio/enzimología , Epitelio/metabolismo , Epitelio/ultraestructura , Trompas Uterinas/enzimología , Femenino , Sustancias de Crecimiento/metabolismo , Humanos , Cavidad Nasal/enzimología , Especificidad de Órganos , Proteínas Tirosina Quinasas Receptoras/biosíntesis , Proteínas Tirosina Quinasas Receptoras/ultraestructura , Receptores de Superficie Celular/biosíntesis , Receptores de Superficie Celular/ultraestructura

RESUMEN

Although carbonic anhydrase (CA) plays an important role in respiration, there is little information about CA in the respiratory system except for the lung. We examined the entire nasal cavity of guinea pig to identify CA activity using an enzyme-histochemical method. CA activity was detected in a group of morphologically distinct nasal epithelial cells. These cells were singly and sparsely distributed mainly in the olfactory epithelium and their number increased rostrocaudally. These cells were also detected in the apical portion of the nasal turbinate, particularly on the nasal endoturbinate, with a more complicated structure, rather than on the nasal septum and the roof of nasal cavity. Although the physiological role of these cells in unknown, based on the morphological and histochemical characteristics and the distribution of these cells, we speculated that they may represent a specialized chemoreceptors.

Asunto(s)

Anhidrasas Carbónicas/metabolismo , Cavidad Nasal/enzimología , Bulbo Olfatorio/enzimología , Animales , Epitelio/enzimología , Femenino , Cobayas , Histocitoquímica

RESUMEN

To get a better insight into the pathophysiology of the nasal changes induced by formaldehyde-ozone mixtures, a 3-day inhalation study was carried out in rats, using intermittent exposure to formaldehyde (3.6 ppm) and ozone (0.4 ppm) alone or in combination and focusing on biochemical and histopathological changes in rat nasal respiratory epithelium. Formaldehyde dehydrogenase, glutathione S-transferase, glutathione reductase, and glucose-6-phosphate dehydrogenase activities in this epithelium were not affected by the individual compounds. However, combined exposure to formaldehyde and ozone resulted in slightly decreased activities of these enzymes. Formaldehyde was found to induce rhinitis, degeneration, frank necrosis, hyperplasia and squamous metaplasia of the ciliated and non-ciliated nasal respiratory epithelium, while ozone induced disarrangement, flattening and slight basal cell hyperplasia of the non-ciliated cuboidal epithelium accompanied by influx of neutrophils. Proliferating cell nuclear antigen (PCNA) expression was elevated not only in nasal areas showing ozone-induced histopathological changes but also in the otherwise normal-appearing epithelium of the nasal septum. No interactive effects were found with respect to proliferative response of the nasal respiratory epithelium after exposure to the formaldehyde-ozone mixture. The present study did not provide evidence of a major role of glutathione and glutathione-dependent enzymes in the pathogenesis of nasal lesions induced by formaldehyde and/or ozone, demonstrated the potential of ozone to affect the mucociliary epithelium lining the nasal septum, and suggested that PCNA expression is a sensitive tool for detection of early effects of respiratory irritants.

Asunto(s)

Formaldehído/toxicidad , Mucosa Nasal/efectos de los fármacos , Mucosa Nasal/patología , Ozono/toxicidad , Administración por Inhalación , Aldehído Deshidrogenasa/efectos de los fármacos , Aldehído Deshidrogenasa/metabolismo , Aldehído Oxidorreductasas/efectos de los fármacos , Aldehído Oxidorreductasas/metabolismo , Animales , Peso Corporal/efectos de los fármacos , División Celular/efectos de los fármacos , Epitelio/efectos de los fármacos , Epitelio/enzimología , Epitelio/patología , Glucosafosfato Deshidrogenasa/metabolismo , Glutatión Peroxidasa/efectos de los fármacos , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/efectos de los fármacos , Glutatión Reductasa/metabolismo , Glutatión Transferasa/efectos de los fármacos , Glutatión Transferasa/metabolismo , Masculino , Cavidad Nasal/efectos de los fármacos , Cavidad Nasal/enzimología , Cavidad Nasal/patología , Mucosa Nasal/enzimología , Proteínas Nucleares/análisis , Antígeno Nuclear de Célula en Proliferación , Ratas , Ratas Wistar , Factores de Tiempo

RESUMEN

Cytotoxicity is primarily limited to the olfactory epithelium of the dorsal meatus region of the nasal cavity of rodents following inhalation exposure to acrylic monomers. To investigate the biochemical basis for this effect, three regions of the Fischer F344N rat nasal cavity were evaluated for carboxylesterase activity for the representative acrylic ester, ethyl acrylate. Prior studies have indicated that the rodent olfactory epithelium is sensitive to the cytotoxic effects of short chain organic acids. In this study, no regional difference in carboxylesterase activity was observed between sensitive and non-sensitive regions of olfactory epithelium. Respiratory epithelium (resistant to cytotoxicity) was found to be have a much lower rate of carboxylesterase activity than olfactory epithelium. These results suggest that the regional distribution of cytotoxicity observed in the rat nasal cavity at high concentrations of inhaled acrylic monomers may be due in part to the amount of released organic acid following deposition. However, the observation of the same esterase activity in sensitive and nonsensitive olfactory regions suggests that nasal air flow patterns and regional deposition may also be critical factors.

Asunto(s)

Acrilatos/metabolismo , Acrilatos/toxicidad , Hidrolasas de Éster Carboxílico/metabolismo , Cavidad Nasal/efectos de los fármacos , Mucosa Olfatoria/efectos de los fármacos , Acrilatos/administración & dosificación , Administración por Inhalación , Animales , Carboxilesterasa , Hidrólisis , Técnicas In Vitro , Masculino , Cavidad Nasal/enzimología , Cavidad Nasal/metabolismo , Mucosa Olfatoria/enzimología , Ratas , Ratas Endogámicas F344

RESUMEN

Many xenobiotics induce lesions within the nasal cavity of experimental animals which are site specific. This site selectivity may be due to regional deposition within the nasal cavity and/or the localisation of biotransformation enzymes. We have developed methodology which allows immunohistochemical localisation of xenobiotic biotransformation enzymes in transverse sections of the rat nasal cavity identical to those normally taken for pathological examination. We report the application of this methodology to six isoenzymes of the glutathione S-transferases (GSTs). All six isoenzymes were predominantly located within olfactory epithelium covering the ethmoturbinates (levels III and IV) and extending forwards into the dorsal meatus (level II). Squamous and transitional epithelia showed little or no staining while respiratory epithelium was weakly stained. Within the respiratory epithelium only the ciliated columnar cells and, to a lesser extent, some of the seromucous glands contained GSTs. Within olfactory epithelium the sustentacular cells, basal cells and subepithelial glands all stained positive for GSTs. The different cell types of olfactory epithelium preferentially express different GST isoenzymes: 1-1 and 2-2 were predominantly located in the subepithelial glands; 3-3, 4-4 and 8-8 in sustentacular and basal cells; 7-7 in basal cells.

Asunto(s)

Glutatión Transferasa/análisis , Cavidad Nasal/enzimología , Animales , Inmunohistoquímica , Isoenzimas/análisis , Masculino , Cavidad Nasal/anatomía & histología , Ratas , Ratas Wistar , Xenobióticos

RESUMEN

The localization of aminopeptidase M (APM), aminopeptidase A (APA) and gama-glutamyltransferase (GGT) activity was studied at light microscope level in the nasal cavity organs of the laboratory rodents (rat, mouse, guinea pig) and human foetuses. All the enzymes were demonstrated histochemically in chloroform-acetone pretreated cryostat sections with application of azocoupling methods (5, 9). These membrane-bound aminopeptidases may participate in the metabolism of peptides in the nasal cavity. They have specific roles as modulators of growth and differentiation of the epithelial cells. The results revealed differences in enzyme patterns between olfactory and respiratory epithelium. GGT seemed to be present only in respiratory epithelium and in the ducts of Bowman's glands. Activity of APM and APA was found mostly in the fibrocytes which adhered to the basal membrane of the epithelium and glands.

Asunto(s)

Aminopeptidasas/análisis , Antígenos CD13/análisis , Cavidad Nasal/enzimología , gamma-Glutamiltransferasa/análisis , Animales , Feto/enzimología , Glutamil Aminopeptidasa , Cobayas , Histocitoquímica , Humanos , Ratones , Ratas