Neurokinin A Is a Main Constituent of Sensory Neurons Innervating the Anterior Segment of the Eye
| Autor: | Elvar Theodorsson, Andrea Laslop, Alfred Doblinger, Christian Kunze, Christian Humpel, W. Philipp, Djavad Lalehabbasi, Wolfgang Göttinger, Ernst Dragosits, Eduard Schmid, Reiner Fischer-Colbrie, Barbara Teuchner, Josef Troger, Johannes Leierer |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Male
medicine.medical_specialty genetic structures Calcitonin Gene-Related Peptide Neurokinin A Radioimmunoassay Substance P Calcitonin gene-related peptide Biology Rats Sprague-Dawley Trigeminal ganglion chemistry.chemical_compound Ciliary body Anterior Eye Segment Tachykinins Cornea Internal medicine medicine Animals Humans RNA Messenger Protein Precursors Fluorescent Antibody Technique Indirect Chromatography High Pressure Liquid In Situ Hybridization Aged Aged 80 and over Neurogenic inflammation Middle Aged respiratory system eye diseases Sensory neuron Rats medicine.anatomical_structure Endocrinology Animals Newborn Trigeminal Ganglion chemistry Female sense organs Trabecular meshwork Capsaicin |
| Zdroj: | Investigative Opthalmology & Visual Science. 46:268 |
| ISSN: | 1552-5783 |
| DOI: | 10.1167/iovs.04-0608 |
| Popis: | PURPOSE. To study the innervation pattern of the anterior segment of the eye by neurokinin (NK)-A-immunoreactive nerves and to determine their sensory origin. METHODS. The presence and distribution of NKA was examined in human eyes by radioimmunoassay and immunofluorescence. The source of nerves was determined by measuring the concentration of NKA in the trigeminal ganglion (TG) in comparison with that of the classic sensory peptides substance P (SP) and calcitonin gene-related peptide (CGRP) and in eye tissues in capsaicin-pretreated rats versus control subjects. The NKA-like immunoreactivities were further characterized by reversed phase HPLC in the rat TG and the human iris- ciliary body complex. The presence of γ-PPT-A mRNA was studied in the rat TG by in situ hybridization. RESULTS. The levels of NKA in human eye tissues were approximately 10 times higher than those of SP but lower than those of CGRP. Nerve fibers were visualized in the cornea, the trabecular meshwork, the iridial stroma, and, prominently, in the sphincter muscle, the ciliary body stroma and muscle and processes, and the choroidal stroma and surrounding blood vessels. In the rat TG, the concentration of NKA was approximately five times higher than that of SP. Capsaicin led to a >60% decrease of the concentration of the peptide in the rat TG and rat eye tissues except for the retina. NKA-like immunoreactivities were present in a single peak corresponding to synthetic NKA, both in the rat TG and in the human iris- ciliary body complex, and numerous ganglion cells of small size were labeled by a γ-PPT-A probe in the rat TG. CONCLUSIONS. The present results clearly demonstrate that NKA is a main constituent of sensory neurons innervating the anterior segment of the eye. The presence of the peptide in C fibers in ocular tissues indicates a participation in sensory transmission and an involvement in the irritative response in the eye, a model for neurogenic inflammation in lower mammals. |
| Databáze: | OpenAIRE |
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