Immunohistochemical Characterization of Neurotransmitters in the Episcleral Circulation in Rats
| Autor: | Alexandra Kaser-Eichberger, Andrea Trost, Anja Maria Ladek, Herbert A. Reitsamer, Markus Lenzhofer, Falk Schroedl, C. Strohmaier, Daniela Bruckner |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty Neurofilament Substance P Calcitonin gene-related peptide Rats Sprague-Dawley 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Internal medicine medicine Animals Galanin Neurotransmitter Neurons Neurotransmitter Agents Colocalization Choline acetyltransferase Immunohistochemistry Rats 030104 developmental biology Endocrinology nervous system chemistry Models Animal Venous Pressure 030217 neurology & neurosurgery Sclera |
| Zdroj: | Investigative ophthalmologyvisual science. 60(8) |
| ISSN: | 1552-5783 |
| Popis: | Purpose Episcleral venous pressure (EVP) greatly influences steady-state IOP and recent evidence suggests a neuronal influence on EVP. Yet little is known about the innervation of the episcleral circulation and, more specifically, the neurotransmitters involved. We identify possible neurotransmitter candidates in the episcleral circulation of rats. Methods Eight immersion-fixated rat eyes taken from four animals were cut into serial sections, followed by standard immunohistochemistry. Antibodies against choline acetyltransferase, dopamine-β-hydroxylase, synaptophysine, PGP 9.5, VIP, neuronal nitric oxide synthase (nNOS), substance P, CGRP, and galanin were used. Additionally, colocalization experiments with smooth muscle actin and neurofilament (200 kDa) were performed. Results In all specimens, the episcleral vessels showed immunoreactivity for smooth muscle actin and were reached by neurofilament (200 kDa)-positive structures. Furthermore, these structures colocalized with immunoreactivity for PGP 9.5, synaptophysine, choline acetyl transferase (ChAT), dopamine-β-hydroxylase, VIP, CGRP, nNOS, substance P and galanin. Conclusions These findings indicate that there is neuronal input to the episcleral circulation. ChAT and VIP as well as dopamine-β-hydroxylase suggest parasympathetic and sympathetic innervation. Further studies are needed on whether the positively-stained structures are of functional significance for the regulation of the episcleral venous pressure and thereby IOP. |
| Databáze: | OpenAIRE |
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