Effects of Levothyroxine on Visual Evoked Potential Impairment Following Local Injections of Lysolecithin Into the Rat Optic Chiasm Publisher



Payghani C¹ ; Khani F¹ ; Rafieezadeh A¹ ; Reisi P¹ ; Alaei H¹ ; Rashidi B² Show Affiliations
Source: International Journal of Preventive Medicine Published:2018

Abstract

Background: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system which has no any known definitive treatment. Studies have shown that thyroid hormones (THs) in addition to their roles in the development of the nervous system and the production of myelin have important roles in the adult's brain function. Since the only way to treat MS is the restoration of myelin, the aim of this study was to evaluate the effects of levothyroxine on visual evoked potential (VEP) impairment following local injections of lysolecithin into the rat optic chiasm. Methods: To induce demyelination, lysolecithin was injected into the optic chiasm of male Wistar rats. VEP recording was used to evaluate demyelination and remyelination before and 10, 17, and 24 days after the lysolecithin injection. The rats received an intraperitoneal injection of levothyroxine with doses 20, 50, and 100 μg/kg in different experimental groups. Results: VEP latency and amplitude showed demyelination at 10 and 17 days after an induced lesion in MS group which was reversed at day 24. Levothyroxine prevented these impairments, especially in high doses. Conclusions: According to the results, lysolecithin‑induced demyelination at optic chiasm and VEP impairments can be restored by administration of levothyroxine. Therefore, THs probably have positive effects in demyelinating diseases. © 2018 International Journal of Preventive Medicine | Published by Wolters Kluwer - Medknow