Document Type : Original Article
Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Department of Medical Basic Sciences, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran;Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
4Neuroscience Research Center (NRC), Iran University of Medical Sciences, Tehran, Iran;5Department of Anatomy, Iran University of Medical Sciences, Tehran, Iran
4Neuroscience Research Center (NRC), Iran University of Medical Sciences, Tehran, Iran;6Skull Base Research Center, Five Senses Institute, Iran University of Medical Sciences, Tehran, Iran
7Aja University of Medical Sciences, Tehran, Iran
8Department of Pharmacology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Spinal cord injury (SCI) is a serious clinical condition that leads to disability. Following primary injury, pro- inflammatory cytokines play an important role in the subsequent secondary events. The thyroid hormone (TH) is known as the modulator of inflammatory cytokines and acts as a neuroprotective agent. Methylprednisolone (MP) is used for the early treatment of SCI. Fluoxetine (FLX), also is known as a selective serotonin reuptake inhibitor (SSRI), has therapeutic potential in neurological disorders. The aim of the present study was to investigate the combined effects of MP and FLX on SCI in the rat hypothyroidism (hypo) model.
Materials and Methods
In this experimental study, 48 male Wistar rats with hypothyroidism were randomly divided into 6 groups (n=8/group): control (Hypo), Hypo+Surgical sham, Hypo+SCI, Hypo+SCI+MP, Hypo+SCI+FLX, and Hypo+SCI+MP+FLX. SCI was created using an aneurysm clip and Hypothyroidism was induced by 6-Propyl-2-thiouracil (PTU) at a dose of 10 mg/kg/day administered intraperitoneally. Following SCI induction, rats received MP and FLX treatments via separate intraperitoneal injections at a dose of 30 and 10 mg/kg/day respectively on the surgery day and FLX continued daily for 3 weeks. The expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were quantified by Real-time polymerase chain reaction (PCR) and Western blotting. Myelination and glutathione (GSH) levels were analyzed by Luxol Fast Blue (LFB) staining and ELISA respectively.
Following combined MP and FLX treatments, the expression levels of TNF-α and IL-6 significantly decreased and GSH level considerably increased in the trial animals.
Our results show the neuroprotective effects of MP and FLX with better results in Hypo+SCI+MP+FLX group. Further study is required to identify the mechanisms involved.