Neuroprotective and Intraocular Pressure-Lowering Effects of (-) Delta -Tetrahydrocannabinol in a Rat Model of Glaucoma
In glaucoma, retinal ganglion cell (RGC) death is induced by many risk factors, including ocular hypertension. It has been proposed that glutamate-mediated oxidative stress may also contribute to this RGC death. Cannabinoids are known to possess therapeutic properties including ocular hypotension an...
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Published in | Ophthalmic research Vol. 39; no. 2; pp. 69 - 75 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
01.03.2007
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Online Access | Get full text |
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Summary: | In glaucoma, retinal ganglion cell (RGC) death is induced by many risk factors, including ocular hypertension. It has been proposed that glutamate-mediated oxidative stress may also contribute to this RGC death. Cannabinoids are known to possess therapeutic properties including ocular hypotension and antioxidation. In this study, we test the hypothesis that (-) Delta 9-tetrahydrocannabinol (THC) lowers intraocular pressure (IOP) and prevents RGC death in a rat model of glaucoma. Arat model of experimental glaucoma with chronic, moderately elevated IOP was produced unilaterally by cauterization of episcleral vessels. Rats received weekly injections of THC at a level of 5 mg/kg or vehicle for 20 weeks. IOP of both eyes was measured weekly on anesthetized animals immediately before THC treatment. RGCs were labeled in a retrograde fashion and counted in whole-mounted retinas. IOP was elevated in all operated eyes 1 day after the operation and remained elevated in the vehicle-treated rats throughout 20 weeks. In THC-treated rats, IOP elevation in operated eyes was diminished 2 weeks after operation and remained reduced. IOP in the contralateral control eyes was not affected by THC. In the operated eyes of vehicle-treated animals, there was a loss of similar to 50 and 40% of the RGCs in the peripheral and central retina, respectively. The RGC loss in the operated eyes of the THC-treated animals was reduced to 10-20%. These results demonstrate that THC is a neuroprotectant that preserves RGCs in an experimental model of glaucoma, possibly through a reduction in IOP. Copyright [copy 2007 S. Karger AG, Basel |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0030-3747 1423-0259 |
DOI: | 10.1159/000099240 |