The Dose-Dependent Antioxidant Effects of Physical Exercise in the Hippocampus of Mice

Exercise increases both the consumption of oxygen and the production of reactive species in biological tissues, and this is counterbalanced by antioxidant adaptations to regular physical training. When the intensity of exercise fluctuates between mild and moderate, it improves the status of reduction–oxidation balance in the brain and induces neuroplasticity. However, intense exercise can oxidize the brain and impair neurological function. The effect of the frequency of exercise, which is an important factor in physical training, is still unknown. The effect of periodic exercise on biomarkers of oxidative stress in the hippocampus of mice was evaluated in this study. Mice were made to run on a treadmill for 8 weeks, two, three, or five times per week, and their hippocampi and quadriceps femoris muscles were then dissected. Biomarkers of oxidative damage were negatively correlated with the frequency of exercise and mitochondrial muscular activity, while the sulfhydryl contents were positively correlated with exercise frequency. A logistic analysis revealed a dose-dependent effect of exercise on these biomarkers. In summary, these results suggested that manipulating the frequency of physical exercise could induce antioxidant-related adaptations in the hippocampi of adult mice.     

小鼠动物实验方法系列专题(七)旷场实验在小鼠行为分析中的应用

旷场实验是一个研究小鼠自发活动与探索行为的实验。该文以GAT1基因敲除小鼠为例介绍了旷场实验的原理和实验步骤。将小鼠置于箱型的旷场装置中,通过录像记录并分析小鼠在旷场中的活动。结果发现,GAT1基因敲除小鼠的自发活动与野生型小鼠无明显差异,而GAT1敲除小鼠的趋避性及焦虑水平较低。旷场实验简单、有效,是一项重要的行为学实验。     

Anticonvulsant and Antioxidant Effects of Cyano-carvone and Its Action on Acetylcholinesterase Activity in Mice Hippocampus

The anticonvulsant effect of cyano-carvone, a monoterpene monocyclic, was investigated in epilepsy model induced by pilocarpine. Cyano-carvone at doses of 25, 50 or 75 mg/kg promoted a reduction of 16.7, 33 and 66.7%, respectively, against pilocarpine-induced seizures, and it was efficacious in increasing both the latency to first seizures and the survival percentage, resulting in 33.3, 67 and 91.7% of protection against death induced by seizures, respectively (P < 0.05). The reference drug atropine (25 mg/kg) also produced a significant protection (100%). Its monoterpene, at 25, 50 and 75 mg/kg, was also capable to increase the latency for installation of status epilepticus induced by pilocarpine, and presented a significant protection against lipid peroxidation and nitrite formation in mice hippocampus (P < 0.05). In addition, it was observed that the cyano-carvone pretreatment increased the acetylcholinesterase activity in mice hippocampus after pilocarpine-induced seizures. The present results clearly indicate the anticonvulsant ability of cyano-carvone, which can be, at least in part, explained by the increased activity of the acetylcholinesterase enzyme. Our data suggest that the action mechanism can also be due to a direct activation of the antioxidant enzymes that could be associated with a reduction observed in oxidative stress in mice hippocampus, probably involving an inhibition of free radical production.     

微生物源性抗氧化剂对小鼠抗氧化性能及免疫功能的影响

旨在探究不同剂量的微生物源性抗氧化剂对小鼠抗氧化性能及免疫功能的影响。将60只28日龄雌性昆明小鼠随机分为4组,每组15只。试验组分别以0.5 g/kg bw*d(低)、1.0 g/kg bw*d(中)、1.5 g/kg bw*d(高)的剂量灌喂微生物源性抗氧化剂,每天1次,连续30 d,灌胃容量为0.2 mL/10 g bw*d,对照组灌喂等容量的蒸馏水。30 d后,测定微生物源性抗氧化剂对小鼠抗氧化性能及免疫功能的影响。结果表明,1.0 g/kg bw*d的微生物源性抗氧化剂可以极显著地提高血清中GSH-Px的活力(P<0.01),显著提高T-SOD活力(P<0.05),降低MDA的含量(P>0.05)。而1.5g/kg bw*d的微生物源性抗氧化剂可以极显著地提高血清中IgA的含量(P<0.01)和IL-2水平,以及ConA刺激的脾淋巴细胞转化率(P<0.01),促进脾脏和胸腺的发育(P>0.05)。提示1.0g/kg bw*d的微生物源性抗氧化剂可以显著增强小鼠的抗氧化能力,1.5 g/kg bw*d的微生物源性抗氧化剂可以增强免疫功能。     

Stem Cell Transplantation Increases Antioxidant Effects in Diabetic Mice

Intra bone marrow-bone marrow transplantation (IBM- BMT) + thymus transplantation (TT) has been shown to reduce the incidence of graft versus host disease (GVHD) and restore donor-derived T cell function. In addition, an increase in insulin sensitivity occurred in db/db mice after IBM-BMT+TT treatment. Heme oxygenase (HO)-1 is a stress inducible enzyme which exert antioxidant, antiapoptotic, and immune-modulating properties. We examined whether IBM-BMT+TT could modulate the expression of HO-1 in the kidneys of db/db mice. Six-week-old db/db mice with blood glucose levels higher than 250 mg/dl were treated with IBM-BMT+TT. Six weeks later, the db/db mice showed decreased body weight, blood glucose levels and insulin, and increased plasma adiponectin levels. The upregulation of HO-1 was associated with significantly (p<0.05) increased levels of peNOS and pAKT, but decreased levels of iNOS in the kidneys of db/db mice. Plasma creatinine levels also decreased (p<0.05), and the expression of type IV collagen was improved. Thus IBM-BMT+TT unregulated the expression of HO-1, peNOS and pAKT, while decreasing iNOS levels in the kidney of db/db mice. This was associated with an improvement in renal function.     

Gliosis in the Mice Hippocampus Without Neuronal Death After Systemic Administration of High Dosage of Tetanus Toxin

Tetanus toxin (TeT), an exotoxin, has been studied to cause tetanus in mammalian brains, and it can block the release of some neurotransmitters and affect seizure propagation. In the present study, we investigated neuronal damage/death and glial changes in the mouse hippocampus after systemic administration (intraperitoneal injection) of TeT 10 and 100 ng/kg. In both the 10 and 100 ng/kg TeT-treated groups, no neuronal death occurred in any subregions of the mouse hippocampus until 24 h post-treatment; however, there were changes in glia in the hippocampus depending on time course and dosage. The morphology of GFAP-immunoreactive astrocytes and Iba-1-immunoreactive microglia was apparently changed in the 100 ng/kg TeT treated-group compared to the 10 ng/kg TeT treated-group. In the 100 ng/kg TeT treated-group, they were increased in size and their immunoreactivity was distinctively increased from 12 h post-treatment. We also found that their protein levels were increased in the hippocampus at 12 h post-treatment of 100 ng/kg TeT. In conclusion, these results indicate that the systemic administration of 100 ng/kg TeT induced a distinctive microglia changes in the mouse hippocampus without any neuronal death/damage.     

Protective Effect of Nerolidol Against Pentylenetetrazol-Induced Kindling,Oxidative Stress and Associated Behavioral Comorbidities in Mice

The present study was aimed to investigate the effect of nerolidol on the development of kindling and associate oxidative stress and behavioral comorbidities. Kindling was induced by repeated injections of a sub-convulsive dose of pentylenetetrazol (PTZ-35 mg/kg; i.p.), at an interval of 48?±?2 h for 43 days (21 injections). Nerolidol was administered daily in three doses (12.5, 25 and 50 mg/kg) along with alternate day PTZ injection. To access behavioral comorbidities, animals were subjected to tail suspension test (TST) and passive shock avoidance (PSA) test to evaluate the associated depression and memory impairment respectively on the last day of PTZ administration. Following behavioral assessment, neurotransmitter level and oxidative stress markers were evaluated in brain. The results showed that nerolidol significantly suppressed the progression of kindling. Also, nerolidol ameliorates the kindling associated depression and memory impairment as indicated by decreased immobility time and increased step down latency, respectively, as compared to vehicle control animals. Further, these behavioral observations were complimented with corresponding neurochemical and oxidative stress markers changes. In conclusion, the results of present study showed that nerolidol treatment has protective effect against PTZ-induced kindling and associated oxidative stress and behavioral comorbidities.     

Use of the Open Field Maze to Measure Locomotor and Anxiety-like Behavior in Mice

Animal models have proven to be invaluable to researchers trying to answer questions regarding the mechanisms of behavior. The Open Field Maze is one of the most commonly used platforms to measure behaviors in animal models. It is a fast and relatively easy test that provides a variety of behavioral information ranging from general ambulatory ability to data regarding the emotionality of the subject animal. As it relates to rodent models, the procedure allows the study of different strains of mice or rats both laboratory bred and wild-captured. The technique also readily lends itself to the investigation of different pharmacological compounds for anxiolytic or anxiogenic effects. Here, a protocol for use of the open field maze to describe mouse behaviors is detailed and a simple analysis of general locomotor ability and anxiety-related emotional behaviors between two strains of C57BL/6 mice is performed. Briefly, using the described protocol we show Wild Type mice exhibited significantly less anxiety related behaviors than did age-matched Knock Out mice while both strains exhibited similar ambulatory ability.     

Effects of Zinc on Interleukins and Antioxidant Enzyme Values in Psoriasis-Induced Mice

The effects of zinc chloride (ZnCl₂), disodium zinc ethylenediamine tetraacetate (Zn-EDTA), and zinc gluconate (Zn-GLU) on the antioxidant enzyme activities and levels of interleukins (ILs) in psoriasis-induced mice were studied. One hundred twenty female mice were randomly divided into six groups with 20 mice in each group: the control, positive control (PC), methotrexate (MTX), ZnCl₂, Zn-EDTA, and Zn-GLU groups. All animals except the control group were given diethylstilbestrol for three consecutive days. After successfully inducing psoriasis, the control and PC groups were given normal saline (i.g.) daily while the remaining groups were given MTX, ZnCl₂, Zn-EDTA, and Zn-GLU, respectively. The results revealed that the zinc supplementation could significantly (p?<?0.05) inhibit mitosis in the mouse vaginal epithelium as methotrexate did and the inhibiting efficacy had nothing to do with the zinc forms. After ZnCl₂, Zn-EDTA, and Zn-GLU supplementation, the levels of liver superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities increased and the concentration of malondialdehyde (MDA) decreased significantly (p?<?0.05) compared to the PC group. The levels of SOD, CAT activity, and MDA level between each zinc supplementation group and MTX group were insignificant (p?>?0.05). The zinc treatments also caused a significant (p?<?0.05) decrease in the raised IL-2 level of animal serum. The results obtained in the present work indicate the potential for zinc as a complementary pharmaceutical intervention for the treatment of topical psoriasis.     

两种莪术类药用植物姜黄素提取物对小鼠抗氧化活性研究

本研究通过对两种莪术类药用植物姜黄素提取物,结合3种姜黄素的含量分析其对小鼠的抗氧化药效。通过高效液相色谱法测定总姜黄素提取物中3种姜黄素的含量。选取48只雌性小鼠,随机分成4组分别灌胃提取液(含1组喂基础饲料)。正常饲喂14 d后,小鼠采血测定SOD (超氧化物歧化酶)、CAT (过氧化氢酶)、GSH-Px (谷胱甘肽过氧化物酶)、XOD (黄嘌呤氧化酶)及NO (一氧化氮)、MDA (丙二醛)含量。结果表明,经姜黄素提取液灌胃的小鼠,SOD、CAT、XOD活性升高,NO含量下降;GSH-PX活性普遍升高,MDA含量普遍下降;2种莪术抗氧化活性具有差异性,浓度或含量与抗氧化活性不具有正相关关系;产地不同,也是影响体内抗氧化活性的因素之一。     

Structural Abnormalities of Hippocampus in 101/HY Mice

We studied cytoarchitectonics of the hippocampus in 101/HY and CBA mice on brain sections stained after Nissl and Timm. In CBA mice, the structure of hippocampus was normal. In 101/HY mice, stratum pyramidale in field CA3 was splitted and the density of pyramidal neurons was decreased. Abnormalities were also found in the zone of suprapyramidal projections of mossy fibers (sp-MF), i.e., terminals of axons of the fascia dentata granular cells on the apical dendrites of pyramids. If in CBA mice the sp-MF zone was normal, i.e., looked like a vast compact formation or dense ordered bundle, in 101/HY mice, the sp-MF zone represented a group of scattered, diffuse, and interrupted bundles of varying length, some of which were incorporated in stratum pyramidale. Possible causes of the described morphological abnormalities are discussed, as well as their relation to specific features of biology, behavior, and neurological status of 101/HY mice.     

Chronic Toxoplasma gondii in Nurr1-Null Heterozygous Mice Exacerbates Elevated Open Field Activity

Latent infection with Toxoplasma gondii is common in humans (approximately 30% of the global population) and is a significant risk factor for schizophrenia. Since prevalence of T. gondii infection is far greater than prevalence of schizophrenia (0.5-1%), genetic risk factors are likely also necessary to contribute to schizophrenia. To test this concept in an animal model, Nurr1-null heterozygous (+/-) mice and wild-type (+/+) mice were evaluate using an emergence test, activity in an open field and with a novel object, response to bobcat urine and prepulse inhibition of the acoustic startle response (PPI) prior to and 6 weeks after infection with T. gondii. In the emergence test, T. gondii infection significantly decreased the amount of time spent in the cylinder. Toxoplasma gondii infection significantly elevated open field activity in both +/+ and +/- mice but this increase was significantly exacerbated in +/- mice. T. gondii infection reduced PPI in male +/- mice but this was not statistically significant. Aversion to bobcat urine was abolished by T. gondii infection in +/+ mice. In female +/- mice, aversion to bobcat urine remained after T. gondii infection while the male +/- mice showed no aversion to bobcat urine. Antibody titers of infected mice were a critical variable associated with changes in open field activity, such that an inverted U shaped relationship existed between antibody titers and the percent change in open field activity with a significant increase in activity at low and medium antibody titers but no effect at high antibody titers. These data demonstrate that the Nurr1 +/- genotype predisposes mice to T. gondii-induced alterations in behaviors that involve dopamine neurotransmission and are associated with symptoms of schizophrenia. We propose that these alterations in murine behavior were due to further exacerbation of the altered dopamine neurotransmission in Nurr1 +/- mice.     

Effects of Septal Grafts on Acetylcholine Release from Rat Hippocampus After 192 IgG-Saporin Lesion

The cholinergic inputs to the rat hippocampus were lesioned by intraseptal injections of 192 IgG-saporin. After 15 days, fetal septal cells were grafted into the hippocampus. Thirteen months later, hippocampal acetylcholine (ACh) release was studied by microdialysis. Lesioning reduced basal ACh release (100%) to 20% of normal, which was compensated for by the graft (71%). Infusion of the serotonin uptake inhibitor citalopram (100 M) enhanced ACh release to the same extent (% of basal release) in all rat groups. Systemic injection of 8-OH-DPAT (0.5 mg/kg, SC), an agonist of 5-HT_1A receptors, caused a smaller ACh release than citalopram. Acetylcholinesterase (AChE) staining and densitometric quantification revealed that the lesion-induced reduction of the AChE-staining density was compensated for by septal grafting. In conclusion, both histochemical and biochemical methods showed that cholinergic hippocampal parameters were drastically impaired by 192 IgG-saporin lesions, but were almost completely restored by septal grafting. The graft responded to intrinsic serotonergic regulation.     

电针对SAMP8小鼠海马区PS1蛋白表达的影响

目的:研究电针对于SAMP8模型小鼠海马区早老蛋白1(presenilian 1,PS1)表达的影响,探讨电针治疗阿尔兹海默病(AD)的作用机制。方法:将20只SAMP8小鼠(早老化小鼠)随机分为模型对照组、电针治疗组,每组10只;10只SAMR1小鼠(正常老化小鼠)组成正常对照组。正常对照组和模型对照组正常饲养15天,在电针治疗组治疗时抓取束缚一次,不做任何治疗;电针治疗组每天治疗前抓取束缚之后再进行电针治疗,治疗穴位选取"百会"、"印堂"、"人中"三穴,频率2 Hz,电流强度以小鼠头部微颤为宜,留针20 min,每日1次,共15天。电针治疗结束后,通过Morris水迷宫实验观察小鼠的行为学变化;通过免疫组化观察SAMP8小鼠海马区PS1蛋白表达情况;通过Western blot方法检测各组海马区的PS1蛋白表达水平。结果:行为学中Morris水迷宫检测显示:模型组与正常对照组比较逃避潜伏时增加,空间探索实验穿越平台次数和平台象限游泳时间明显减少(P0.05,P0.01);电针治疗组逃避潜伏时明显减少,空间探索实验穿越平台次数和平台象限游泳时间明显增加(P0.05);免疫组化观察各组海马区PS1蛋白表达,电针治疗组较模型组明显降低;Western blot结果显示PS1蛋白在海马区表达水平,模型组高于正常对照组(P0.01),而电针治疗组低于模型组(P0.01)。结论:电针可以改善小鼠的学习记忆能力,而且电针治疗组海马区PS1蛋白含量明显低于模型组,电针治疗可能参与减弱PS1蛋白的表达,降低Aβ水平,对于AD治疗有益。     

The Production of Tumor Necrosis Factor in Cells of Tumor-Bearing Mice After Total-Body Microwave Irradiation and Antioxidant Diet

The effects of repeated treatment with weak microwaves (MW) (8.15–18 GHz, 1 µW/cm², 1.5 h daily) and diet with antioxidants (AO) (β-carotene, α-tocopherol, and ubiquinone Q₉) on production of tumor necrosis factor (TNF) in macrophages and T lymphocytes of healthy and tumor-bearing mice (TBM) were studied. Tumor size and mortality of TBM were also followed. Microwave radiation and antioxidant diet stimulated production of TNF in cells from healthy mice. At early stages, tumor growth induced TNF production in mouse cells; however, this effect decreased as tumors grew. In TBM exposed to MW, TNF production was higher than in unirradiated TBM. Oppositely, AO diet induced TNF production in healthy mice but did not affect TNF secretion in TBM. Accordingly, prolonged treatment of TBM to MW, but not to AO diet, decreased tumor growth rate and increased overall animal longevity. These results suggest that diminished tumor growth rate due to extremely low-level MW exposure of mice carrying tumors, at least in part, was caused by enhancement in TNF production and accumulation of plasma TNF.     

Bioelectromagnetic Field Effects on Cancer Cells and Mice Tumors

We present possibilities and trends of ELF bioelectromagnetic effects in the mT amplitude range on cancer cells and on mice bearing tumors. In contrast to invasive electrochemotherapy and electrogenetherapy, using mostly needle electrodes and single high-amplitude electropulses for treatment, extremely low-frequency (ELF) pulsating electromagnetic fields (PEMF) and sinusoidal electromagnetic fields (SEMF) induce tumor cell apoptosis, inhibit angiogenesis, impede proliferation of neoplastic cells, and cause necrosis non invasively, whereas human lymphocytes are negligibly affected. Our successful results in killing cancer cells—analyzed by trypan blue staining or by flow cytometry—and of the inhibition of MX-1 tumors in mice by 15–20?mT, 50?Hz treatment in a solenoid coil also in the presence of bleomycin are presented in comparison to similar experimental results from the literature.

In conclusion, the synergistic combinations of PEMF or SEMF with hyperthermia (41.5°C) and/or cancerostatic agents presented in the tables for cells and mice offer a basis for further development of an adjuvant treatment for patients suffering from malignant tumors and metastases pending the near-term development of suitable solenoids of 45–60?cm in diameter, producing >20?mT in their cores.     

Effects of Tenascin-C Knockout on Cerebral Vasospasm After Experimental Subarachnoid Hemorrhage in Mice

A matricellular protein tenascin-C (TNC) has been suggested to play a role in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH), but the direct evidence remains lacking. In this study, we examined effects of TNC knockout (TNKO) on cerebral vasospasm after experimental SAH in mice. C57BL/6 wild-type (WT) or TNKO mice were subjected to SAH by endovascular puncture. Ten WT and ten TNKO mice were randomized to WT sham (n = 4), TNKO sham (n = 4), WT SAH (n = 6), and TNKO SAH (n = 6) groups. In addition to neurobehavioral impairments and severity of SAH, cerebral vasospasm was assessed by morphometric measurements of the left internal carotid artery (ICA). Infiltration of inflammatory cells in the subarachnoid periarterial space was also assessed, and expressions of TNC and mitogen-activated protein kinases (MAPKs) in the ICA were immunohistochemically evaluated at 24 h post-surgery. TNC was induced in the smooth muscle cell layers and the adventitia in the spastic ICAs as well as the periarterial inflammatory cells in WT SAH mice. Compared with WT SAH mice, TNKO SAH mice showed better neurological scores and less severe cerebral vasospasm, as well as fewer inflammatory cell infiltration in the periarterial space. Post-SAH activation of MAPKs in the smooth muscle cell layers of the ICAs was also prevented in TNKO SAH mice. The findings in the present study suggest that TNC causes the development of cerebral vasospasm via pro-inflammatory effects and activation of MAPKs.     

Neurogenesis in the Hippocampus of Mice Exposed to Short-Term Hindlimb Unloading

Journal of Evolutionary Biochemistry and Physiology - Long-term spaceflights and simulated microgravity negatively affect the number of cognitive functions, including memory, learning, spatial...