Date of Graduation

Fall 2012

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Paul Durham

Keywords

corneal wound, scratch, CGRP, neuropeptides, eye

Subject Categories

Biology

Abstract

Corneal wounds represent the most common type of ocular injury. Injuries to the corneal tissues can result in significant damage with loss of epithelial tissue and nerve fibers, causing a delay in healing time and ultimately problems with vision. Sensory neurons located throughout the cornea exert important trophic effects that are implicated in the wound healing process. Calcitonin gene-related peptide (CGRP), a 37-amino acid neuropeptide, is a biologically active protein that has many functions throughout the nervous system including promoting vasodilation and cell proliferation. Based on the expression of CGRP and its receptor, RAMP1, in adult Sprague-Dawley rats, we hypothesized that topical administration of CGRP to a corneal epithelial scratch wound would increase the rate of wound healing. One linear scratch, penetrating only the corneal epithelium, was created on both the left and right eye of the animal using a sterile 18-guage needle. Each wound was treated with a 20 microliter CGRP solution (500 nM diluted in 0.9% saline) or saline immediately after wounding as well as 2 hours and 6 hours following eye injury. Wounds treated with CGRP showed full wound closure 24 hours later while saline treated wounds were not fully healed. In addition, at the time of full wound closure, the morphology of CGRP treated wounds more closely resembled that of normal, healthy corneal tissue with respect to cellular organization, granulation tissue, and overall size of corneal epithelium when compared to saline treated wounds. Results from my study suggest that topical CGRP administration to a corneal wound promotes wound closure and morphological changes indicative of healthy corneal wound healing.

Copyright

© Joshua Blake Hayden

Campus Only

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