Limits...
In vivo determination of mouse olfactory mucus cation concentrations in normal and inflammatory states.

Selvaraj S, Liu K, Robinson AM, Epstein VA, Conley DB, Kern RC, Richter CP - PLoS ONE (2012)

Bottom Line: To validate the findings in the animal model, olfactory threshold was measured in 11 healthy human participants using Sniffin' Sticks before and after nasal irrigation with solutions that were composed of either of the cation concentrations.No difference existed in [Ca(2+)] (0.50±0.12 mM versus 0.54±0.06 mM, p = 0.39).Nasal irrigation with a corresponding solution induced olfactory threshold shift in humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America.

ABSTRACT

Objective: Olfaction is impaired in chronic rhinosinusitis (CRS). The study has two aims: (1) to determine whether changes in cation concentration occur in the olfactory mucus of mice with CRS, which may affect chemo-electrical transduction, (2) and to examine whether these alterations are physiologically significant in humans.

Study design: Animal study in mice and translational study in humans.

Methods: Inflammation was induced by sensitization and chronic exposure of 16 C57BL/6 mice to Aspergillus fumigatus. The control group included 16 untreated mice. Ion-selective microelectrodes were used to measure free cation concentrations in the olfactory mucus of 8 mice from each treatment group, while the remaining mice were sacrificed for histology. To validate the findings in the animal model, olfactory threshold was measured in 11 healthy human participants using Sniffin' Sticks before and after nasal irrigation with solutions that were composed of either of the cation concentrations.

Results: In 8 mice, olfactory mucus of chronically inflamed mice had lower [Na(+)] (84.8±4.45 mM versus 93.73±3.06 mM, p = 0.02), and higher [K(+)] (7.2±0.65 mM versus 5.7±0.20 mM, p = 0.04) than controls. No difference existed in [Ca(2+)] (0.50±0.12 mM versus 0.54±0.06 mM, p = 0.39). In humans, rinsing with solutions replicating ion concentrations of the mouse mucosa with chronic inflammation caused a significant elevation in the median olfactory threshold (9.0 to 4.8, p = 0.003) but not with the control solution (8.3 to 7.8, p = 0.75).

Conclusion: Chronic inflammation elevates potassium and lowers sodium ion concentration in mice olfactory mucus. Nasal irrigation with a corresponding solution induced olfactory threshold shift in humans.

Show MeSH

Related in: MedlinePlus

Demonstration of eosinophils and major basic protein (MBP) in a chronic allergen exposed mouse.A) Low power image of Sirius Red and hematoxylin stained coronal section of a chronic allergen exposed mouse. Numerals identify the six sampling areas, where specific 100 micron square areas were designated for eosinophil counting. The solid arrow indicates the region of the olfactory cleft where ion concentration measurements were made, in the dorsal recess near sampling area 5. The shaded arrow indicates the general dorsal to ventral transition from Olfactory (OE), Transitional (TE) to Respiratory (RE) epithelia in the mouse nose. Mucus is evident within the lumen (M). Bar = 500 µm. B) Higher power image from panel 1 showing counting regions 1 and 2. Arrows indicate Sirius Red stained eosinophils localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Bar = 100 µm. C) Localization of MBP in the coronal section of a chronic allergen exposed mouse. Primary antibody is mouse anti-MBP and non-specific binding is blocked by mouse IgG incubation. Brown staining indicates MPB (arrow). Regions of Olfactory (OE), Transitional (TE) and Respiratory (RE) epithelia are indicated. Mucus is evident within the lumen (M). Bar = 50 µm. D) Higher power image from panel 3. Arrows indicate MBP localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Olfactory epithelium (OE) is largely devoid of MBP. Mucus (M) does not show any significant non-specific staining. Bar = 50 µm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3401282&req=5

pone-0039600-g001: Demonstration of eosinophils and major basic protein (MBP) in a chronic allergen exposed mouse.A) Low power image of Sirius Red and hematoxylin stained coronal section of a chronic allergen exposed mouse. Numerals identify the six sampling areas, where specific 100 micron square areas were designated for eosinophil counting. The solid arrow indicates the region of the olfactory cleft where ion concentration measurements were made, in the dorsal recess near sampling area 5. The shaded arrow indicates the general dorsal to ventral transition from Olfactory (OE), Transitional (TE) to Respiratory (RE) epithelia in the mouse nose. Mucus is evident within the lumen (M). Bar = 500 µm. B) Higher power image from panel 1 showing counting regions 1 and 2. Arrows indicate Sirius Red stained eosinophils localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Bar = 100 µm. C) Localization of MBP in the coronal section of a chronic allergen exposed mouse. Primary antibody is mouse anti-MBP and non-specific binding is blocked by mouse IgG incubation. Brown staining indicates MPB (arrow). Regions of Olfactory (OE), Transitional (TE) and Respiratory (RE) epithelia are indicated. Mucus is evident within the lumen (M). Bar = 50 µm. D) Higher power image from panel 3. Arrows indicate MBP localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Olfactory epithelium (OE) is largely devoid of MBP. Mucus (M) does not show any significant non-specific staining. Bar = 50 µm.

Mentions: Sensitized animals chronically exposed to A. fumigatus showed dense inflammatory infiltrates in many areas of the respiratory epithelium and mild inflammation in the olfactory epithelium. Almost all of the inflammatory infiltrates had eosinophilic granules and bi-lobed nuclei, which are typical of murine eosinophils. Quantification of eosinophilic infiltrates in the respiratory and olfactory neuroepithelium was performed in 6 corresponding locations (Fig. 1A and B). Mice chronically exposed to A. fumigatus showed significantly greater eosinophil counts in the respiratory epithelium (35.5±5.4) as compared to untreated animals (0.31±0.18, p<0.001). A small, but statistically significant increase of the eosinophil count in the olfactory epithelium of the chronically exposed group was also observed (1.25±0.38) as compared to the untreated group, which showed no eosinophil infiltration in any of the animals (p<0.01). Values are displayed as average ± standard error (Fig. 2).


In vivo determination of mouse olfactory mucus cation concentrations in normal and inflammatory states.

Selvaraj S, Liu K, Robinson AM, Epstein VA, Conley DB, Kern RC, Richter CP - PLoS ONE (2012)

Demonstration of eosinophils and major basic protein (MBP) in a chronic allergen exposed mouse.A) Low power image of Sirius Red and hematoxylin stained coronal section of a chronic allergen exposed mouse. Numerals identify the six sampling areas, where specific 100 micron square areas were designated for eosinophil counting. The solid arrow indicates the region of the olfactory cleft where ion concentration measurements were made, in the dorsal recess near sampling area 5. The shaded arrow indicates the general dorsal to ventral transition from Olfactory (OE), Transitional (TE) to Respiratory (RE) epithelia in the mouse nose. Mucus is evident within the lumen (M). Bar = 500 µm. B) Higher power image from panel 1 showing counting regions 1 and 2. Arrows indicate Sirius Red stained eosinophils localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Bar = 100 µm. C) Localization of MBP in the coronal section of a chronic allergen exposed mouse. Primary antibody is mouse anti-MBP and non-specific binding is blocked by mouse IgG incubation. Brown staining indicates MPB (arrow). Regions of Olfactory (OE), Transitional (TE) and Respiratory (RE) epithelia are indicated. Mucus is evident within the lumen (M). Bar = 50 µm. D) Higher power image from panel 3. Arrows indicate MBP localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Olfactory epithelium (OE) is largely devoid of MBP. Mucus (M) does not show any significant non-specific staining. Bar = 50 µm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3401282&req=5

pone-0039600-g001: Demonstration of eosinophils and major basic protein (MBP) in a chronic allergen exposed mouse.A) Low power image of Sirius Red and hematoxylin stained coronal section of a chronic allergen exposed mouse. Numerals identify the six sampling areas, where specific 100 micron square areas were designated for eosinophil counting. The solid arrow indicates the region of the olfactory cleft where ion concentration measurements were made, in the dorsal recess near sampling area 5. The shaded arrow indicates the general dorsal to ventral transition from Olfactory (OE), Transitional (TE) to Respiratory (RE) epithelia in the mouse nose. Mucus is evident within the lumen (M). Bar = 500 µm. B) Higher power image from panel 1 showing counting regions 1 and 2. Arrows indicate Sirius Red stained eosinophils localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Bar = 100 µm. C) Localization of MBP in the coronal section of a chronic allergen exposed mouse. Primary antibody is mouse anti-MBP and non-specific binding is blocked by mouse IgG incubation. Brown staining indicates MPB (arrow). Regions of Olfactory (OE), Transitional (TE) and Respiratory (RE) epithelia are indicated. Mucus is evident within the lumen (M). Bar = 50 µm. D) Higher power image from panel 3. Arrows indicate MBP localized to Lamina Propria (LP) and Respiratory Epithelium (RE). Olfactory epithelium (OE) is largely devoid of MBP. Mucus (M) does not show any significant non-specific staining. Bar = 50 µm.
Mentions: Sensitized animals chronically exposed to A. fumigatus showed dense inflammatory infiltrates in many areas of the respiratory epithelium and mild inflammation in the olfactory epithelium. Almost all of the inflammatory infiltrates had eosinophilic granules and bi-lobed nuclei, which are typical of murine eosinophils. Quantification of eosinophilic infiltrates in the respiratory and olfactory neuroepithelium was performed in 6 corresponding locations (Fig. 1A and B). Mice chronically exposed to A. fumigatus showed significantly greater eosinophil counts in the respiratory epithelium (35.5±5.4) as compared to untreated animals (0.31±0.18, p<0.001). A small, but statistically significant increase of the eosinophil count in the olfactory epithelium of the chronically exposed group was also observed (1.25±0.38) as compared to the untreated group, which showed no eosinophil infiltration in any of the animals (p<0.01). Values are displayed as average ± standard error (Fig. 2).

Bottom Line: To validate the findings in the animal model, olfactory threshold was measured in 11 healthy human participants using Sniffin' Sticks before and after nasal irrigation with solutions that were composed of either of the cation concentrations.No difference existed in [Ca(2+)] (0.50±0.12 mM versus 0.54±0.06 mM, p = 0.39).Nasal irrigation with a corresponding solution induced olfactory threshold shift in humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America.

ABSTRACT

Objective: Olfaction is impaired in chronic rhinosinusitis (CRS). The study has two aims: (1) to determine whether changes in cation concentration occur in the olfactory mucus of mice with CRS, which may affect chemo-electrical transduction, (2) and to examine whether these alterations are physiologically significant in humans.

Study design: Animal study in mice and translational study in humans.

Methods: Inflammation was induced by sensitization and chronic exposure of 16 C57BL/6 mice to Aspergillus fumigatus. The control group included 16 untreated mice. Ion-selective microelectrodes were used to measure free cation concentrations in the olfactory mucus of 8 mice from each treatment group, while the remaining mice were sacrificed for histology. To validate the findings in the animal model, olfactory threshold was measured in 11 healthy human participants using Sniffin' Sticks before and after nasal irrigation with solutions that were composed of either of the cation concentrations.

Results: In 8 mice, olfactory mucus of chronically inflamed mice had lower [Na(+)] (84.8±4.45 mM versus 93.73±3.06 mM, p = 0.02), and higher [K(+)] (7.2±0.65 mM versus 5.7±0.20 mM, p = 0.04) than controls. No difference existed in [Ca(2+)] (0.50±0.12 mM versus 0.54±0.06 mM, p = 0.39). In humans, rinsing with solutions replicating ion concentrations of the mouse mucosa with chronic inflammation caused a significant elevation in the median olfactory threshold (9.0 to 4.8, p = 0.003) but not with the control solution (8.3 to 7.8, p = 0.75).

Conclusion: Chronic inflammation elevates potassium and lowers sodium ion concentration in mice olfactory mucus. Nasal irrigation with a corresponding solution induced olfactory threshold shift in humans.

Show MeSH
Related in: MedlinePlus