Innervation of nasal turbinate blood vessels in rhinitic and nonrhinitic children

Tic disorder in allergic rhinitis children and adolescents: a case-control study

BACKGROUND

Allergic rhinitis is the most common allergic disease. It can accompany psychological disorders such as tic disorders due to the prolonged course of the symptoms of allergic rhinitis. This pioneer case-control study aims to investigate tic disorders in children and adolescents under 18 years of age diagnosed with allergic rhinitis.

METHOD

The case group in this study consisted of patients who had both allergic rhinitis and tic disorders. Patients with allergic rhinitis without tic disorders were also enrolled as the control group with matched gender and age. Demographic characteristics, tic classifications, and contributing factors for allergic rhinitis and tic disorders were studied among the cases. Tic disorders were evaluated using DSM-5 criteria for the classification of tic disorders.

RESULTS

47 patients in the case group and 47 patients in the control group were included in this study. 53.2% and 46.8% were males and females in the case group, respectively. The mean age of the patients was 10.46 ± 3.97 years old. Sound tics were more common among the patients compared to motor tics. Patients with concomitant AR and tic disorders had more days per week with AR symptoms (P-value ≤ 0.001; OR (every day vs. three days a week = 11.02(2.98, 40.76))). Most patients with sound tick were women (p: 0.026), and most patients with motion tic were in the Provisional tic disorder group (p: 0.001). The history of infantile eczema was seen more in patients without sound tic (p: 0.025), and otitis media was significantly less common among patients with sound tics (p: 0.026). Provisional tic disorder was the most common class among the patients. In the case group (coexistence between allergic rhinitis and tic) compared to the control group, patients had significantly more days with AR symptoms per week.

CONCLUSION

This preliminary study indicates that Provisional tic disorder was the most common classification of tic among patients with allergic rhinitis, especially in patients with motor tics. Asthma in motor tics, a history of food allergy in infancy, and a history of infantile eczema were also common among patients with vocal tics. Also, patients with allergic rhinitis and tic had more severe disease (more symptoms per week) than those with rhinitis alone. These findings emphasize the association of tic disorders with immunological pathways.

Perivascular Innervation in the Nasal Mucosa and Clinical Findings in Patients with Allergic Rhinitis and Idiopathic Rhinitis

Introduction  The nonspecific hyperreactivity of rhinitis has been attributed to neurotrophins activating sensory nerves and inflammatory cells. The relationship between these markers and the intensity of the symptoms is not well established and few studies have evaluated individuals with idiopathic rhinitis. Objective  The present study aims to evaluate whether perivascular innervation and nerve growth factor (NGF) are related to the intensity of the clinical conditions in allergic rhinitis (AR) and idiopathic rhinitis (IR). Methods  A total of 15 patients with AR and 15 patients with IR with the indication for inferior turbinectomy (associated or not with septoplasty) were selected. The patients received a score according to their signs and symptoms. After the surgery, we quantified eosinophils, mast cells, NGF, and nerve fibers in the nasal turbinate. Results  The score of the signs and symptoms was higher in the AR group. Nerve growth factor was found in the cytoplasm of inflammatory cells in the submucosa in greater quantity in the AR group. The nerve fibers were distributed throughout the tissue, mainly in the subepithelial, glandular, and vascular regions, and there was no difference between the groups. Greater perivascular innervation was associated with a higher signs and symptoms score. Conclusions  We concluded that these findings suggest that the NGF produced by submucosal inflammatory cells stimulates increased perivascular innervation in rhinitis, thus directly reflecting in more intense clinical conditions, especially in AR.

The nose has it: Opportunities and challenges for intranasal drug administration for neurologic conditions including seizure clusters

Nasal administration of treatments for neurologic conditions, including rescue therapies to treat seizure clusters among people with epilepsy, represents a meaningful advance in patient care. Nasal anatomy and physiology underpin the multiple advantages of nasal administration but also present challenges that must be addressed in any successful nasal formulation. Nasal cavity anatomy is complex, with a modest surface area for absorption that limits the dose volume of an intranasal formulation. The mucociliary clearance mechanism and natural barriers of the nasal epithelia must be overcome for adequate absorption. An extensive vasculature and the presence of olfactory nerves in the nasal cavity enable both systemic and direct-to-brain delivery of drugs targeting the central nervous system. Two intranasal benzodiazepine rescue therapies have been approved by the US Food and Drug Administration for seizure-cluster treatment, in addition to the traditional rectal formulation. Nasal sprays are easy to use and offer the potential for quick and consistent bioavailability. This review aims to increase the clinician's understanding of nasal anatomy and physiology and of the formulation of intranasal rescue therapies and to facilitate patient education and incorporate intranasal rescue therapies for seizure clusters (also known as acute repetitive seizures) into their seizure action plans.

Itch Beyond the Skin-Mucosal Itch

Itch is a nociceptive sensation linked with reflexes and cognitive motor actions. We traditionally think of itch as a sensation of the skin related to allergy, an insect sting or interestingly, anxiety and frustration. Less understood and considered are the physiological processes involved in the itching sensation that occurs at mucosal and junctional dermal sites, which is extraordinary as from an evolutionary point of view these sites serve important guardian roles, rich in sensory nerves and inflammatory cells. Despite itch being an ancient reflex and evolutionarily conserved phenomenon, better clinical understanding of the nuances between sites of itch sensation may lead to improved clinical outcomes. This review invites readers to appreciate itch beyond the skin by highlighting several specific itch patterns-nasal, oral, auricular, vulvovaginal, anal, and perineal itch-the pathophysiological mechanisms that underlie them, the clinical patterns these may cause, and some unique treatments.

Mediators, Receptors, and Signalling Pathways in the Anti-Inflammatory and Antihyperalgesic Effects of Acupuncture

Acupuncture has been used for millennia to treat allergic diseases including both intermittent rhinitis and persistent rhinitis. Besides the research on the efficacy and safety of acupuncture treatment for allergic rhinitis, research has also investigated how acupuncture might modulate immune function to exert anti-inflammatory effects. A proposed model has previously hypothesized that acupuncture might downregulate proinflammatory neuropeptides, proinflammatory cytokines, and neurotrophins, modulating transient receptor potential vallinoid (TRPV1), a G-protein coupled receptor which plays a central role in allergic rhinitis. Recent research has been largely supportive of this model. New advances in research include the discovery of a novel cholinergic anti-inflammatory pathway activated by acupuncture. A chemokine-mediated proliferation of opioid-containing macrophages in inflamed tissues, in response to acupuncture, has also been demonstrated for the first time. Further research on the complex cross talk between receptors during inflammation is also helping to elucidate the mediators and signalling pathways activated by acupuncture.

The anti-inflammatory effects of acupuncture and their relevance to allergic rhinitis: a narrative review and proposed model

Classical literature indicates that acupuncture has been used for millennia to treat numerous inflammatory conditions, including allergic rhinitis. Recent research has examined some of the mechanisms underpinning acupuncture's anti-inflammatory effects which include mediation by sympathetic and parasympathetic pathways. The hypothalamus-pituitary-adrenal (HPA) axis has been reported to mediate the antioedema effects of acupuncture, but not antihyperalgesic actions during inflammation. Other reported anti-inflammatory effects of acupuncture include an antihistamine action and downregulation of proinflammatory cytokines (such as TNF-α, IL-1β, IL-6, and IL-10), proinflammatory neuropeptides (such as SP, CGRP, and VIP), and neurotrophins (such as NGF and BDNF) which can enhance and prolong inflammatory response. Acupuncture has been reported to suppress the expression of COX-1, COX-2, and iNOS during experimentally induced inflammation. Downregulation of the expression and sensitivity of the transient receptor potential vallinoid 1 (TRPV1) after acupuncture has been reported. In summary, acupuncture may exert anti-inflammatory effects through a complex neuro-endocrino-immunological network of actions. Many of these generic anti-inflammatory effects of acupuncture are of direct relevance to allergic rhinitis; however, more research is needed to elucidate specifically how immune mechanisms might be modulated by acupuncture in allergic rhinitis, and to this end a proposed model is offered to guide further research.

Innate immune properties of selected human neuropeptides against Moraxella catarrhalis and nontypeable Haemophilus influenzae

Background

Considerable evidence supports the concept of active communication between the nervous and immune systems. One class of such communicators are the neuropeptides (NPs). Recent reports have highlighted the antimicrobial activity of neuropeptides, placing them among the integral components of innate immune defense. This study examined the action of four human neuropeptides: calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), substance P (SP) and somatostatin (SOM), which are accessible in the upper respiratory tract, against two human-specific respiratory pathogens. We studied: (i) neuropeptide-mediated direct antibacterial activity exerted against Moraxella catarrhalis and nontypeable Haemophilus influenzae, and (ii) indirect immunomodulatory role of these neuropeptides in the neutrophil-mediated phagocytosis of indicated pathogens.

Results

We found that 100 micromolar concentrations of CGRP, NPY, SP, and SOM effectively permeabilized bacterial membranes and showed (except SOM) bactericidal activity against both pathogens. SOM acted only bacteriostatically. However the killing efficacy was dependent on the bactericidal assay used. The rank order of killing NP effect was: NPY ≥ CGRP > SP >> SOM and correlated with their potency to permeabilize bacterial membranes. The killing and permeabilization activity of the analyzed NPs showed significant correlation with several physicochemical properties and amino acid composition of the neuropeptides. M. catarrhalis was more sensitive to neuropeptides than nontypeable H. influenzae.

The immunomodulatory bimodal effect of physiological concentrations of CGRP, NPY, and SP on the phagocytic function of human neutrophils against M. catarrhalis and H. influenzae was observed both in the ingestion (pathogen uptake) and reactive oxygen species generation stages. This effect was also dependent on the distinct type of pathogen recognition (opsonic versus nonopsonic).

Conclusions

The present results indicate that neuropeptides such as CGRP, NPY, and SP can effectively participate in the direct and indirect elimination of human-specific respiratory pathogens. Because the studied NPs show both direct and indirect modulating antimicrobial potency, they seem to be important molecules involved in the innate host defense against M. catarrhalis and nontypeable H. influenzae.

Origins of Western diseases

Recent gynaecological studies show that childbirth, constipation, trauma and surgery cause injuries to autonomic nerves at different anatomical sites in the female pelvis resulting in endometriosis, adenomyosis and fibroids. Re-growth of abnormal nerves causes allodynic symptoms ('light touch causing pain or discomfort') some years later including vulvodynia, dyspareunia, dysmenorrhea, irritative bladder and bowel symptoms. Further consequences of autonomic denervation include tissue hypoplasia and hyperplasia, visceral dysfunction, susceptibility to infection, alcohol, tobacco and drugs, as well as pain with sensitization of the central nervous system. The 'autonomic denervation' view extrapolates these observations from the female pelvis to the varied anatomy of branches of the cardiac and coeliac plexi to provide primary mechanisms for many forms of Western disease. This account sets out the autonomic denervation view, identifies features of autonomic denervation in extrapelvic organs, and, contrasts it with prior accounts of chronic Western diseases including those of DP Burkitt, PRJ Burch and DP Barker.

Subjective nasal fullness and objective congestion

How well do subjective descriptions of the sensation of nasal closure or absence of nasal patency agree with objective measures of nasal geometry and airflow? Problems with this concept begin with terminology. "Congestion" has been applied to both the subjective and objective measures. Therefore, the term "fullness" will be used to describe perceptions of nasal mucosal heaviness or blockage that subjects with allergic rhinitis articulate. "Congestion" will refer to the objective measures used to assess patency. Sensations attributed to the nasal mucosa are highly integrated interpretations summed from multiple subsets of nociceptive and other neurons. Activation of sensor systems is required to depolarize afferent neurons. These sensors and other receptor proteins can be modulated by inflammation as part of the neural plasticity that leads to increased sensitivity to nasal stimuli. This plasticity and hyperalgesia may extend from the afferent neuron to spinal cord dorsal horn synapses, and regulatory and analytical regions of the brainstem and cerebrum. Although glandular hypersecretion can deliver obstructing material into the nasal cavities, the dilation of deep venous sinusoids is the strongest factor regulating nasal airspace volumes. There is a long history of attempts to correlate subjective sensations to objective measurements such as airflow resistance (rhinomanometry), nasal wall geometry (acoustic rhinometry), and peak nasal inspiratory flow. The medical evidence supporting each method has been analyzed on the basis of the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system. These results provide a starting point for linking the outcomes of pathophysiological processes with a patient's psychometrically calibrated sensation of airflow.

Physiology and pathophysiology of respiratory mucosa of the nose and the paranasal sinuses

In this review, anatomy and physiology of the respiratory mucosa of nose and paranasal sinuses are summarized under the aspect of its clinical significance. Basics of endonasal cleaning including mucociliary clearance and nasal reflexes, as well as defence mechanisms are explained. Physiological wound healing, aspects of endonasal topical medical therapy and typical diagnostic procedures to evaluate the respiratory functions are presented. Finally, the pathophysiologies of different subtypes of non-allergic rhinitis are outlined together with treatment recommendations.

Autonomic denervation and the origins of chronic Western diseases

Many chronic Western diseases result from lifestyles that include refined diets, poor bowel habits, limited physical exercise and suboptimal patterns of childbirth. Western diets result in reduced stool weights, increased bowel transit times and persistent physical efforts during defaecation. Prolonged physical efforts during defaecation and childbirth cause latent, or direct, injuries to branches of the cardiac (thorax), coeliac (abdomen) and hypogastric (pelvis) plexi. Injuries to autonomic nerves result in impaired visceral function including visceral dysmotility, tissue hypoplasia and hyperplasia, increased susceptibility to infection, and, aberrant reinnervation with sensitisation of the central nervous system (CNS). These unrecognised injuries are vulnerable to the long list of causes of autonomic Dysfunction, e.g. stress, alcohol, drugs, infection, trauma, cancer, etc. Specific injuries at different anatomical locations in midline autonomic pathways give rise to a wide range of Western diseases from infancy to old age, through diverse and cumulative mechanisms.

Effect of resection of the posterior nasal nerve on functional and morphological changes in the inferior turbinate mucosa

CONCLUSIONS

The underlying pathophysiological mechanisms of the posterior nasal nerve (PNN) resection involved the suppression of the secretogogue motor and the inhibition of neurogenic inflammation induced by parasympathetic and sensory denervation.

OBJECTIVE

The study was designed to clarify the underlying mechanisms of the resection of the PNN.

PATIENTS AND METHODS

Ten patients with allergic rhinitis and non-allergic chronic rhinitis were enrolled in the study. Clinical symptoms were evaluated before and after administration of oxitropium bromide aerosol, and after the PNN resection. Biopsy specimens from the inferior turbinate mucosa obtained from five patients before and after resection of the PNN were examined.

RESULTS

The application of oxitropium bromide resulted in a significant reduction of both watery rhinorrhea and nasal obstruction, but not sneezing or postnasal drip. Resection of the PNN also significantly improved both rhinorrhea and nasal obstruction. Morphometric analysis of the density of the nasal gland showed a significant reduction, whereas no significant change was recognized in the density of the vessels. A significant reduction in the number of infiltrating neutrophils, eosinophils, and lymphocytes was recognized.

Neuronal markers in allergic rhinitis: expression and correlation with sensory testing

INTRODUCTION

Although the role of immunoglobulin E-mediated hypersensitivity reactions in allergic rhinitis is well known, the relative contribution of sensory nerves to the symptoms of rhinitis is uncertain. This study looked at the level of specific neuronal markers including the nerve marker protein gene product 9.5 (PGP 9.5), sensory and autonomic neuropeptides, the capsaicin/heat receptor TRPV1, and nerve growth factor (NGF) in patients with allergic rhinitis and controls and their correlation with nasal sensitivity.

MATERIALS AND METHODS

Forty patients (23 controls, 17 rhinitis) having nasal surgery were recruited. Nasal sensitivity was tested using graded monofilaments. Inferior turbinate biopsies were collected and studied using immunohistology, with measurement of nerve fibers by direct observation or computerized image analysis.

RESULTS

Nerve fibers (PGP 9.5) in the epithelium, subepithelium, and glandular/vascular regions were significantly increased in allergic rhinitis (P=.037, <.01, and .04, respectively), as were subepithelial and glandular/vascular fibers immunoreactive for neuropeptide substance P (P=.04 subepithelium; .02 glandular/vascular) and neuropeptide tyrosine (P<.01 glandular/vascular), markers for sensory and sympathetic nerves, respectively. TRPV1 epithelial fiber counts were higher in rhinitis, but this was not statistically significant. Epithelial NGF immunoreactivity (% area) was significantly increased in rhinitis (P=.027). Nasal sensitivity was correlated significantly with PGP 9.5 subepithelial innervation (control touch P=.023, irritation P=.046; rhinitis touch P=.042, irritation P=.043). A correlation was also observed between epithelial NGF and subepithelial PGP 9.5 innervation, which included all subjects (P=.044).

CONCLUSION

The increased number and specific phenotypical changes of sensory nerves may play a role in nasal hypersensitivity and provide new targets for the treatment of rhinitis.

Adenosine sensory transduction pathways contribute to activation of the sensory irritation response to inspired irritant vapors

The molecular mechanisms through which sensory irritants stimulate nasal trigeminal nerves are poorly understood. The current study was aimed at evaluating the potential contribution of purinergic sensory transduction pathways in this process. Aerosols of 4-36 mM adenosine 5'-triphosphate (ATP) and adenosine both acted as sensory irritants. Large dose capsaicin pretreatment to induce degeneration of transient receptor potential vanilloid type-1 (TRPV1)-expressing C fibers greatly reduced, but did not abolish, the sensory irritation response to ATP aerosol and was without effect on the response to adenosine aerosol, indicating that ATP acts largely on capsaicin-sensitive (primarily C fibers) and adenosine acts on capsaicin-insensitive (primarily Adelta fibers) nerves. The response to adenosine was diminished by pretreatment with the broad-based adenosine receptor antagonist theophylline (20 mg/kg) and A1-selective antagonist 8-cyclopentyl-1,3-dipropylxanthine (0.1 mg/kg), providing evidence that adenosine stimulates capsaicin-insensitive nerves via the A1 receptor. The sensory irritation responses to 275 ppm styrene and 110 ppm acetic acid vapors were significantly reduced by theophylline pretreatment suggesting a role for adenosine signaling pathways in activation of the sensory irritant response by these vapors. If sensory nerves are activated by mediators that are released from injured airway mucosal cells, then nasal sensory nerve activation may be a reflection of irritant-induced alterations in airway cell integrity.

Neuropeptide immunofluorescence in human nasal mucosa: assessment of the technique for vasoactive intestinal peptide (VIP)

Neuropeptides are important neurotransmitters in nasal physiology and the increasing knowledge of their role in nasal diseases brings new therapeutic perspectives. The investigation of human nasal mucosa neuropeptides is based mostly on immunocytochemistry, a complex approach whose resulting factors may be variable. Aiming to make this kind of research available, an immunofluorescence approach for vasoactive intestinal peptide (VIP) in human nasal mucosa is proposed and evaluated.

Study design

Transversal cohort.

Material and Method

Human inferior turbinate samples were obtained at time of nasal surgery from eight patients. The samples were fixed in Zamboni solution (4% phosphate-buffered paraformaldehyde and 0.4% picric acid), snap-frozen and stored at -70ºC. 14 µm sections were then obtained. Immunofluorescence staining for VIP (Peninsula Laboratories) was performed and its images documented by conventional photography. The method's specificity, sensitivity and reproducibility of execution were evaluated. Additionally, the reproducibility of interpretation of results was evaluated through the comparison of staining scores (0 to 4) attributed to the images by six observers.

Results

The results showed the approach to be very specific and sensible, besides being reproducible in its execution. The interpretation of results may depend on the observer's accuracy in judging immunofluorescence images, but it showed uniformity.

Conclusion

The proposed method was highly useful for research purposes in neuropeptides in human nasal mucosa.

Neuronal Plasticity in Persistent Perennial Allergic Rhinitis

OBJECTIVE

Persistent perennial allergic rhinitis belongs to the most frequent diseases in occupational and environmental medicine. Because the innervation may play a role in the pathogenesis of the disease, the present study analyzed nasal mucosal nerve profiles.

METHODS

Neuropeptide-containing nerve fibers were examined using immunohistochemistry and related to eosinophil and mast cell numbers.

RESULTS

In contrast to constant numbers of mast cells, there was a significant increase in the number of eosinophils. Immunohistochemistry for calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and neuropeptide tyrosine (NPY) revealed abundant staining of mucosal nerves. Semiquantitative assessment of nerve fiber neuropeptide density demonstrated a significant increase of VIP-positive fibers in rhinitis tissues.

CONCLUSIONS

The present data indicate a differential regulation of neuropeptide-containing nerve fibers with increased numbers of VIPergic fibers suggesting a modulatory role of the upper airway innervation in perennial allergic rhinitis.

Inspiratory flow in the nose: a model coupling flow and vasoerectile tissue distensibility

We have developed a discrete multisegmental model describing the coupling between inspiratory flow and nasal wall distensibility. This model is composed of 14 individualized compliant elements, each with its own relationship between cross-sectional area and transmural pressure. Conceptually, this model is based on flow limitation induced by the narrowing of duct due to collapsing pressure. For a given inspiratory pressure and for a given compliance distribution, this model predicts the area profile and inspiratory flow. Acoustic rhinometry and posterior rhinomanometry were used to determine the initial geometric area and mechanical characteristics of each element. The proposed model, used under steady-state conditions, is able to simulate the pressure-flow relationship observed in vivo under normal conditions (4 subjects) and under pathological conditions (4 vasomotor rhinitis and 3 valve syndrome subjects). Our results suggest that nasal wall compliance is an essential parameter to understand the nasal inspiratory flow limitation phenomenon and the associated increase of resistance that is well known to physiologists. By predicting the functional pressure-flow relationship, this model could be a useful tool for the clinician to evaluate the potential effects of treatments.

Phenotypic alteration of neuropeptide-containing nerve fibres in seasonal intermittent allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is the most common allergic disease affecting the respiratory tract. Next to inflammatory changes, the airway innervation plays an important modulatory role in the pathogenesis of the disease.

OBJECTIVE

To examine the participation of different neuropeptides in the human nasal mucosa of intermittent (seasonal) AR tissues in the allergic season.

METHODS

Immunohistochemistry for substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and neuropeptide tyrosine (NPY) was related to the characterization of inflammatory cells in tissues of patients with seasonal AR (n=18).

RESULTS

While there was a significant increase in the number of eosinophils present if compared with a control group, no changes occurred in mast cell numbers. Immunostaining was abundantly found in different nerve fibre populations of both groups. SP expression was significantly increased in mucosal nerve fibres of patients with intermittent (seasonal) AR. Also, significantly increased numbers of VIP- and NPY-immunoreactive nerve fibres were found in biopsies of rhinitis patients in comparison with sections of normal human nasal mucosa. In contrast, CGRP expression did not change significantly.

CONCLUSION

The increase of neuropeptide expression in mucosal nerve fibres indicates a major role of the autonomous mucosal innervation in the pathophysiology of intermittent (seasonal) AR.

Neural expression and increased lavage fluid levels of secretoneurin in seasonal allergic rhinitis

Secretoneurin is a neuropeptide potentially involved in migration of eosinophils, monocytes, and dendritic cells. Whether secretoneurin is present in the human airway mucosa and whether it is released at ongoing allergic airway inflammation is currently unknown. In patients with allergic rhinitis, we have explored the occurrence of secretoneurin in nasal mucosal biopsies and lavage fluids before and during natural allergen exposure. Immunohistochemical analysis revealed an abundance of nerves displaying secretoneurin immunoreactivity, which were distributed predominantly around blood vessels and submucosal glands. A majority of nerve fibers containing vesicular acetylcholine transporter, tyrosine hydroxylase, calcitonin gene-related peptide, and vasoactive intestinal peptide were also secretoneurin-immunoreactive, indicating a localization of secretoneurin in cholinergic, adrenergic, and sensory nerves. Lavage fluid levels of secretoneurin were increased at allergen exposure (p < 0.01-0.05). Levels of secretoneurin did not correlate with eosinophil cationic protein (rho = 0.1, p = 0.7). We conclude that secretoneurin has a widespread occurrence in nasal mucosal nerves of patients with seasonal allergic rhinitis and that increased nasal lavage fluid levels of secretoneurin may characterize ongoing allergen exposure. These data favor a role of secretoneurin in the local traffic of immune cells in human airway mucosa.

Toxic rhinitis-induced changes of human nasal mucosa innervation

Irritative toxic rhinitis is a nasal disorder induced by chemical compounds like ozone, formaldehyde, nickel, chrome, solvents and tobacco smoke. These noxious stimuli may have effects on the nasal innervation leading to a cascade of neuro-immune interactions and an augmentation of the symptoms. Here we examined changes in the neuropeptide content of mucosal parasympathetic, sympathetic and sensory nerves of patients with toxic rhinitis caused by chronic cigarette smoke exposure. Semiquantitative immunohistochemistry using antibodies against calcitonin gene-related peptide (CGRP), substance P (SP), neuropeptide tyrosine (NPY), and vasoactive intestinal peptide (VIP) was carried out on cryostat sections of human nasal mucosa obtained from normal subjects and patients with toxic rhinitis and revealed significant differences between both groups. Toxic rhinitis patients had significantly elevated expression scores for VIP (2.83 +/- 0.31 vs 1.27 +/- 0.47 control group) and NPY (3.17 +/- 0.31 vs 0.91 +/- 0.37 control group) revealing an increase of mediators in distinct subpopulations of airway nerves. In summary, the present studies indicate a differential participation of subclasses of mucosal nerves in the pathophysiology of toxic rhinitis. Airway innervation may have a major role in the pathophysiology of toxic rhinitis associated with chronic cigarette smoke exposure.

Innervation of human nasal mucosa in environmentally triggered hyperreflectoric rhinitis

Hyperreflectoric rhinitis is related to an unspecific hyperreactivity probably caused by chemical irritants. As a major modulatory role may be attributed to the mucosal innervation, the present study was carried out to examine possible changes in the nasal mucosa innervation. Immunohistochemistry for the neuropeptides vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), substance P (SP) and neuropeptide tyrosine (NPY) revealed abundant staining of nerve fibers. Neuropeptide-contents in mucosal nerves was then quantitatively assessed and significant increases were found for SP (3.00 +/- 0.37 vs. 1.64 +/- 0.34 control group staining intensity) and VIP (2.33 +/- 0.42 vs. 0.82 +/- 0.33). In conclusion, these findings demonstrated differences in human nasal mucosa innervation between nonrhinitic and hyperreflectoric rhinitic subjects and provide evidence for a modulatory participation of neuropeptide-specific subpopulations of nerve fibers in hyperreflectoric rhinitis.

Immunocytochemical and biochemical identification of angiotensin II in human nasal tissue

Angiotensin II (ANG II) was identified immunocytochemically and biochemically in biopsy samples of human nasal tissue. Staining for ANG II was predominantly found in structures similar to a string of pearls with consecutive short varicose areas, which is characteristic for neuronal tissue. The localization of ANG II in neurons was confirmed by positive staining of adjacent tissue sections with a specific antibody to neurofilament or doublestaining with both antibodies in one section. Likewise, ANG II-like material was also determined radioimmunologically in nasal tissue extracts. The concentrations of ANG II varied form 1.28 to 332.78 fmol/g wet tissue weight with an average concentration of 79.61+/-44.09 fmol ANG II/g wet tissue weight (mean+/-SEM, n=7). The ANG II-immunoreactive material was further characterized biochemically by HPLC on a reversed phase C(18) column in an acetonitrile and methanol gradient as Ile(5)-ANG II and ANG II metabolites such as Ile(4)-ANG III, Ile(3)-ANG II(3-8)hexapeptide and Ile(2)-ANG II(4-8)pentapeptide.

Neurology of allergic inflammation and rhinitis

Afferent nerves, derived from the trigeminal ganglion, and postganglionic autonomic nerves, derived from sympathetic and parasympathetic ganglia expressing many different neurotransmitters, innervate the nose. Reflexes that serve to optimize the air-conditioning function of the nose by altering sinus blood flow, or serve to protect the nasal mucosal surface by mucus secretion, vasodilatation, and sneezing, can be initiated by a variety of stimuli, including allergen, cold air, and chemical irritation. Activation of nasal afferent nerves can also have profound effects on respiration, heart rate, blood pressure, and airway caliber (the diving response). Dysregulation of the nerves in the nose plays an integral role in the pathogenesis of allergic rhinitis. Axon reflexes can precipitate inflammatory responses in the nose, resulting in plasma extravasation and inflammatory cell recruitment, while allergic inflammation can produce neuronal hyper-responsiveness. Targeting the neuronal dysregulation in the nose may be beneficial in treating upper airway disease.

Mechanisms of allergic rhinitis

The pathogenesis of allergic rhinitis can be better appreciated by understanding the numerous protective mechanisms available for mucosal defense. The system of TH2 lymphocytes, IgE production, mast cell degranulation, eosinophil infiltration, and resident cell responses are central to our understanding and treatment of allergic rhinitis. Histamine remains preeminent in causing the cardinal symptoms of the immediate allergic reaction: itching, watery discharge, and nasal swelling. Recruitment and activation mechanisms responsible for the late-phase allergic response are also reviewed.

Substance P immunoreactive sensory axons as a subset of the total axonal population in the maxillary sinus of the rabbit: a characterization of normal and infected mucosa

Substance P (SP), one of the neuropeptides released from sensory nerves, is thought to mediate neurogenic inflammation. Although SP immunoreactive axons have been described in the sinus mucosa, no attempt has been made to characterize SP fibers as a subset of all axons present in the sinus mucosa. In addition, no study to date has characterized the changes in infected sinus mucosa. The maxillary sinus mucosa of New Zealand white rabbits was harvested from control animals and in animals with induced maxillary sinusitis. Immunohistochemical staining of the sinus mucosa for both Protein Gene Product 9.5 (PGP), a nonspecific marker for all nerves, and for SP was performed on 11 animals: 3 controls and 8 infected. In sinus mucosa from the control rabbits, <50% of all axons labeled by PGP were immunoreactive for SP. In infected mucosa, the absolute number of axons found by PGP staining decreased and nearly all of these remaining fibers were also immunoreactive for SP. We conclude that the phenotypical labeling of nerve fibers seen in normal mucosa is altered by bacterial-induced infection.

Innervation of blood vessels in the vomeronasal complex of the rat

We have made an immunohistochemical study of the vomeronasal (VN) complex of 12-day-old rats to characterize the innervation of its blood vessels. The VN complex can be subdivided into rostral, middle and caudal segments, each one with a particular vascularization pattern. Several small vessels were associated with the rostral segment, whereas a large venous sinus ran along the middle and caudal segments. Immunostaining for alpha-smooth muscle actin demonstrated that the muscular sheath was asymmetric, with more cells layers in its lateral than in its medial walls. Nerves were demonstrated with antisera against protein gene product 9.5 (PGP), and against several molecules associated with specific classes of nerve fibers: the C-terminal peptide of neuropeptide Y (CPON), calcitonin gene-related peptide (CGRP), substance P (SP), galanin (GAL), vasoactive intestinal peptide (VIP) and neuronal nitric oxide synthase (NOS). The latter, was also studied with NADPH-diaphorase. Vascular associated fibers exhibited NOS-, CPON-, GAL-, CGRP-, SP- and VIP-immunoreactivity. Only the vessels of the rostral segment showed VIP-immunoreactive fibers. Each wall of the venous sinus exhibited different types of nerve fibers. CPON-, GAL-, CGRP- and SP-immunoreactive fibers concentrated in the medial wall, whereas NOS-immunoreactive ones concentrated in the lateral wall. This distribution of vascular fibers, plus the presence of sensory fibers exhibiting CGRP-, SP- and GAL-immunoreactivity within the pseudostratified epithelium of the VN tube, would be relevant to understand the operation of the pumping mechanism regulating influx and efflux from the VN tube.