Search

Orexin A and B are hypothalamic peptides with a wide variety of effects such as anti-inflammation and neuroprotection. Impaired function of orexin system has been reported in some neurodegenerative diseases like Parkinson, Huntington and Alzheimer. In this study, the mRNA expression levels of some hypothalamic peptides were investigated in C57BL/6 female mice with experimental autoimmune encephalomyelitis (EAE). Animals were randomly divided into two control and EAE groups. EAE was induced by administration of myelin oligodendrocyte glycoprotein (MOG) with complete Ferund’s adjuvant and pertussis toxin. Twenty-first days following immunization, mice were decapitated to remove the brains. Then, the expression profiles of prepro-orexin, orexin 1 receptors (OX1R) and orexin 2 receptors (OX2R) in hypothalamic region were assessed using real-time PCR method. In this study, we found a considerable increase in the mRNA expression of OX1R and OX2R following EAE induction in C57BL/6 mice. Elevation levels of OX1R and OX2R following EAE induction suggest that alteration in orexinergic system may involve in pathogenesis of multiple sclerosis.

Increased levels of proinflammatory cytokines have been recorded after the onset of transient or permanent brain ischemia and are usually associated with exacerbation of ischemic injury. Embolic stroke model is more relevant to the pathophysiological situation in such patients, because the majority of ischemic injuries in humans are induced by old thrombi that originate from the heart and carotid arteries. Therefore, the aim of the present study was to investigate changes of inflammatory cytokines after embolic stroke. Rats were subjected to embolic stroke, induced by a natural old clot which was injected in Middle Cerebral Artery (MCA), or sham stroke, which the same volume of saline was injected into the MCA. At 48 h after stroke induction, the levels of 5 cytokines (IL-1α and β, IL-6, IFN-γ and TNF-α) were determined in 500 µg of total protein using the Bio-Plex Rat Cytokine Array (BioRad), according to the manufacturer’s instructions in ischemic and non- ischemic cortices. While stroke animals showed infarctions and neurological deficits, we did not observe any cerebral infarction and neurological deficits in sham-operated animals. The levels of IL-1α (p=0.000) and -β (p =0.004), IL-6 (p =0.008), TNF-α (p =0.000) and IFN-γ (p =0.044) were significantly increased compared to sham treated animals. The findings of the present study suggest that part of ischemic injury in the embolic stroke may be mediated through the increased levels of inflammatory cytokines.