vasoactive-intestinal-peptide and Conjunctivitis--Allergic

The mechanisms of naso-ocular interaction in allergic rhinoconjunctivitis are not well understood. Neurogenic inflammation affects both eyes and nose via the same neurogenic factors. The purpose of this study was to investigate the effects of neurogenic inflammation on conjunctival inflammation following nasal allergen provocation.. Sensitized rats were exposed to ovalbumin (OVA) via the nose. Parts of the nasal mucosa and conjunctivae were sliced and used for hematoxylin-eosin staining, immunohistochemical analysis, western blotting, and real-time polymerase chain reaction. The slides were observed under a light microscope, and the acquired images were analyzed. The levels of substance P (SP), vasoactive intestinal peptide (VIP), and nerve growth factor (NGF) were detected.. The levels of SP, VIP, and NGF were increased in both nasal mucosa and conjunctivae 1 h and 24 h after OVA administration (p < 0.05). Higher levels of SP, VIP, and NGF expression were observed in the nasal mucosa and conjunctivae 24 h after OVA administration (p < 0.05). Following damage of the nasal sensory nerves by capsaicin, the protein and mRNA levels of SP, VIP, and NGF were reduced.. In conclusion, the increased levels of VIP, SP, and NGF might be responsible for the ocular reaction following nasal challenge with allergen in rats.

Topics: Animals; Biomarkers; Conjunctiva; Conjunctivitis, Allergic; Nasal Mucosa; Nerve Growth Factor; Neurogenic Inflammation; Rats; Substance P; Vasoactive Intestinal Peptide

Growing evidence is showing a role of neurogenic inflammation in allergic reactions, with sensory and autonomic nerve fibers releasing neuromediators, which may actively participate in the allergic inflammatory cascade. Although the cornea is the most densely innervated tissue of the human body, little is known on the role of neuromediators at the ocular surface. In this study, we aimed at evaluating the role of substance P (SP), calcitonine gene related peptide (CGRP), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) in allergic reactions of the ocular surface.. Fifteen patients with allergic conjunctivitis (6 female, 9 male, mean age 30±8 years) in non-active phase, and 10 age-matched healthy subjects were included in this study. The conjunctival provocation test (CPT) with allergen was performed in all allergic patients and in 5 healthy subjects. Tear samples were collected and the tear content of VIP, NPY, CGRP, and SP was measured by ELISA at baseline and after CPT. The Mann-Whitney U-test and Wilcoxon test were used to compare neuromediator tear levels.. No significant differences in neuropeptide tear levels were observed between healthy and allergic patients in non-active phase. CPT induced conjunctival hyperemia and itching in all allergic patients, while no reaction was observed in the control eyes and in healthy subjects. In allergic patients SP, CGRP, and VIP, but not NPY, were significantly higher after CPT as compared to baseline (SP: 3.9±1.3 ng/ml versus 5.8±1.1 ng/ml, p=0.011; CGRP: 5.5±2.3 ng/ml versus 7.3±2.7 ng/ml; p=0.002; VIP: 4±0.9 ng/ml versus 5.1±1.5 ng/ml, p=0.007). No significant changes were observed in the control eyes of allergic patients challenged with diluent and in healthy subjects after allergen provocation.. Locally-released neuromediators may participate in modulating the allergic response of the ocular surface.

Topics: Adult; Allergens; Animals; Bronchial Provocation Tests; Calcitonin Gene-Related Peptide; Conjunctivitis, Allergic; Enzyme-Linked Immunosorbent Assay; Eye; Female; Humans; Inflammation; Male; Neuropeptide Y; Neuropeptides; Pyroglyphidae; Tears; Vasoactive Intestinal Peptide

There is growing evidence that autonomic innervation is involved in the pathogenesis of mucus hypersecretion, goblet cell hyperplasia, and conjunctival hyperreactivity.. To determine the expression of neurotransmitters and neurotransmitter receptors in vernal keratoconjunctivitis (VKC) tissues to evaluate whether neurogenic inflammation plays a role in this ocular atopic-related disorder.. Biopsy specimens of upper tarsal conjunctiva from 8 VKC patients with active inflammation and from 4 healthy subjects were processed for immunohistochemistry using anti-M1, anti-M2, and anti-M3 muscarinic receptors; beta1-adrenergic receptor; vasoactive intestinal peptide; nerve growth factor; and protein gene product 9.5, a marker of nerve fibers.. In the conjunctival epithelium of VKC patients, M1 muscarinic receptor, nerve growth factor, and protein gene product 9.5 expression were decreased, whereas M2 and M3 muscarinic receptors and beta1-adrenergic receptor were irregularly distributed, compared with control subjects. Neurotransmitter receptors and vasoactive intestinal peptide expression were increased in the substantia propria-localized infiltrate of VKC compared with healthy tissue. Nerve growth factor and protein gene product 9.5 staining was also enhanced in the conjunctival stroma of VKC vs healthy conjunctiva.. The inflamed conjunctiva of VKC patients demonstrated an obvious alteration in muscarinic and beta1-adrenergic receptor, vasoactive intestinal peptide, protein gene product 9.5, and nerve growth factor expression. These results substantiate the involvement of an autonomic dysfunction in the pathogenesis of VKC.

Topics: Adolescent; Autonomic Nervous System; Biomarkers; Child; Conjunctiva; Conjunctivitis, Allergic; Female; Humans; Immunoenzyme Techniques; Male; Nerve Fibers; Nerve Growth Factors; Receptors, Adrenergic, beta-1; Receptors, Muscarinic; Ubiquitin Thiolesterase; Vasoactive Intestinal Peptide