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Secretoneurin in the peripheral ocular innervation
Josef Troger1, Alfred Doblinger, Johannes Leierer
1Department of Ophthalmology, Medical University of Innsbruck, 6020 Innsbruck, Austria. josef.troger@uibk.ac.at
Investigative Ophthalmology & Visual Science
|January 27, 2005
Summary
Secretoneurin, a sensory neuropeptide, innervates the anterior segment of the eye, particularly in capsaicin-sensitive neurons. This peptide may play a role in ocular irritation and neovascularization.
Area of Science:
- Ophthalmology
- Neuroscience
- Molecular Biology
Background:
- Secretoneurin is a neuropeptide with potential roles in sensory pathways.
- The innervation of the anterior segment of the eye is crucial for various physiological and pathological processes.
Purpose of the Study:
- To determine if secretoneurin acts as a sensory neuropeptide in the anterior segment of the eye.
- To investigate the distribution and source of secretoneurin in ocular tissues.
Main Methods:
- Radioimmunoassay and immunofluorescence were used to detect secretoneurin in human and rat eyes.
- Trigeminal and superior cervical ganglia were analyzed in control and capsaicin-treated rats.
- In situ hybridization and gel filtration chromatography were employed to study secretoneurin synthesis in rats.
Main Results:
- Secretoneurin was found in various ocular structures, including the cornea, iris, ciliary body, and choroid.
- Nerve fibers containing secretoneurin were identified as capsaicin-sensitive and originating from the trigeminal ganglion.
- Sympathetic denervation did not affect secretoneurin levels, except in the dilator muscle.
Conclusions:
- Secretoneurin is a constituent of capsaicin-sensitive sensory neurons and unmyelinated C-fibers in the rat eye.
- The peptide is likely involved in ocular irritative responses and neurogenic inflammation.
- Secretoneurin's association with blood vessels suggests a role in neovascularization.
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