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Chronic intermittent hypobaric hypoxia (CIHH) is known to have an anti-hypertensive effect, which might be related to modulation of the baroreflex in rats with renal vascular hypertension (RVH). In this study, RVH was induced by the 2-kidney-1-clip method (2K1C) in adult male Sprague-Dawley rats. The rats were then treated with hypobaric hypoxia simulating 5000 m altitude for 6 h/day for 28 days. The arterial blood pressure (ABP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were measured before and after microinjection of L-arginine into the nucleus tractus solitarii (NTS) in anesthetized rats. Evoked excitatory postsynaptic currents (eEPSCs) and spontaneous EPSCs (sEPSCs) were recorded in anterogradely-labeled NTS neurons receiving baroreceptor afferents. We measured the protein expression of neuronal nitric oxide synthase (nNOS) and endothelial NOS (eNOS) in the NTS. The results showed that the ABP in RVH rats was significantly lower after CIHH treatment. The inhibition of ABP, HR, and RSNA induced by L-arginine was less in RVH rats than in sham rats, and greater in the CIHH-treated RVH rats than the untreated RVH rats. The eEPSC amplitude in NTS neurons receiving baroreceptor afferents was lower in the RVH rats than in the sham rats and recovered after CIHH. The protein expression of nNOS and eNOS in the NTS was lower in the RVH rats than in the sham rats and this decrease was reversed by CIHH. In short, CIHH treatment decreases ABP in RVH rats via up-regulating NOS expression in the NTS.
Assuntos
Animais , Masculino , Barorreflexo , Fisiologia , Pressão Sanguínea , Hipertensão , Metabolismo , Hipóxia , Rim , Metabolismo , Óxido Nítrico Sintase Tipo I , Metabolismo , Ratos Sprague-Dawley , Núcleo Solitário , MetabolismoRESUMO
Uncoupling protein 4 (UCP4) is a member of the multigenic uncoupling proteins (UCPs), specific expressing in the cerebral cortex and hippocampus. UCP4 plays an important role in Parkinson's disease, multiple sclerosis, epilepsy, stroke, brain trauma and other central nervous system diseases by uncoupling, decreasing mitochondrial membrane potential,regulating Ca2+ homeostasis and oxidative stress. This article reviews UCP4 and its roles in the central nervous system diseases in order to provide certain basis for the development of UCP4targeted medication.
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Thrombolysis can effectively treat ischemic stroke, but it has the risk of resulting in hemorrhagic transformation. A number of studies have suggested that hemorrhagic transforma-tion is closely correlated with matrix metalloproteinase mediated disruption of blood-brain barrier and the increase of vasopermeability. The increase plasma matrix metalloproteinase(MMP) -9 can be used as an independent predictor of hemorrhagic transformation. Using MMP inhibitors during the early cerebral ischemia may reduce the incidence and severity of hemor-rhagic transformation, however, it needs to be further validated.
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Neuroglobin(Ngb)is one of the members of oxygen-carrying globin family.It mainly exists in neurons in a monomeric form,which is closely correlated the oxygen supply to brain.Brain hypoxia/ischemia can induce the high expression of Ngb,and as an endogenous neuroprotective factor,it protects ischemic neurons from ischemia/hypoxia injury.This article reviews the distribution,structure and function of Ngb,and its potential protective effects and mechanisms in cerebral ischemia/hypoxia cerebral injury.
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Tumor necrosis factor-like weak inducer of apoptosis(TWEAK)is a new member of the tumor necrosis factor family.After TWEAK binding to its receptor Fn14.it induces extensive biological activities.TWEAK-Fn14 pathway participates in pathophysiological mechanisms of cell apoptosis,regulation of the blood-brain barrier permeability and inflammation in central nervous system,and it is closely correlated with the diseases such as ischernic stroke.multiple sclerosis and gliocytoma.
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Tumor necrosis factor-related apoptosis-inducing ligand(TRAIL)is the third member of the tumor necrosis factor(TNF)superfamily.It has received much concern because of its selective killing effect on tumor cells and virus infected cells.However,the subsequent studies have suggested that TRAIL also induces normal cells,such as the death of neurons and oligodendrocytes.TRAIL is associated with a variety of central nervous system diseases including primary brain tumor,multipie sclerosis and ischemic stroke.
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Objective:To study the expression of neuroglobin (Ngb) in rat cerebral ischemia model and the neuroprotective effect of Ngb after ischemia and hypoxia. Methods: Totally 113 Sprague-Dawley rats were randomly divided into sham-operated group, middle cerebral artery occlusion (MCAO) group, hemorrhagic infarction (HI) group and hemin treatment group. The brain water content, infarcted tissue volume, neuropathologic changes (H-E staining) and expression of Ngb (immunocytochemical staining) were examined 3, 6, 12, and 24 h after model establishment. Results: The brain water contents and the infarcted tissue volumes in the hemin treatment group were significantly different from those of the MCAO group and HI group (P
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AIM:To observe the effect of oxymatrine on the expression of Toll-like receptor 4 (TLR4) in brain tissue surrounding cerebral ischemic rats. METHODS: The FCI model with thread embolism of middle cerebral artery occlusion (MCAO) in rats was made, 80 male SD rats were divided randomly into shamed-operation, saline and oxymatrine groups, and the oxymatrine group was further divided into two sub-groups which were dealt with the low and high dose of oxymatrine. The expression level of TLR4 and TLR4 mRNA in the brain tissue surrounding cerebral ischemic was determined simultaneously by the usage of immunohistochemical and RT-PCR method respectively. RESULTS: The expression of TLR4 gene in saline group was higher evidently than that in shamed-operation group (P