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Effect of policosanol on cerebral ischemia in Mongolian gerbils  [cached]
Molina V.,Arruzazabala M.L.,Carbajal D.,Valdés S.
Brazilian Journal of Medical and Biological Research , 1999,
Abstract: Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane wax, whose main component is octacosanol. An inhibitory effect of policosanol on platelet aggregation and cerebral ischemia in animal models has been reported. Thus, the objective of the present study was to evaluate the effect of policosanol on cerebral ischemia induced by unilateral carotid ligation and bilateral clamping and recirculation in Mongolian gerbils. Policosanol (200 mg/kg) administered immediately after unilateral carotid ligation and at 12- or 24-h intervals for 48 h significantly inhibited mortality and clinical symptoms when compared with controls, whereas lower doses (100 mg/kg) were not effective. Control animals showed swelling (tissue vacuolization) and necrosis of neurons in all areas of the brain studied (frontal cortex, hippocampus, striatum and olfactory tubercle), showing a similar injury profile. In the group treated with 200 mg/kg policosanol swelling and necrosis were significantly reduced when compared with the control group. In another experimental model, comparison between groups showed that the brain water content of control gerbils (N = 15) was significantly higher after 15 min of clamping and 4 h of recirculation than in sham-operated animals (N = 13), whereas policosanol (200 mg/kg) (N = 19) significantly reduced the edema compared with the control group, with a cerebral water content identical to that of the sham-operated animals. cAMP levels in the brain of control-ligated Mongolian gerbils (N = 8) were significantly lower than those of sham-operated animals (N = 10). The policosanol-treated group (N = 10) showed significantly higher cAMP levels (2.68 pmol/g of tissue) than the positive control (1.91 pmol/g of tissue) and similar to those of non-ligated gerbils (2.97 pmol/g of tissue). In conclusion, our results show an anti-ischemic effect of policosanol administered after induction of cerebral ischemia, in two different experimental models in Mongolian gerbils, suggesting a possible therapeutic effect in cerebral vascular disorders.
Neuroprotectionby MK-801 following cerebral ischemia in Mongolian gerbils
Radenovi? Lidija,Selakovi? Vesna,An?us P.R.
Archives of Biological Sciences , 2008, DOI: 10.2298/abs0803341r
Abstract: Global cerebral ischemia in Mongolian gerbils is an established model in experimental research on cerebral ischemia, which is characterized morphologically by selective neuronal damage in the hippocampus, striatum, and cortex. Elevated glutamate levels are thought to be a primary cause of neuronal death after global cerebral ischemia. The purpose of this study was to investigate the potential neuroprotective effects of dizocilpine malate (MK-801), a non-competitive glutamate antagonist, in the model of 10-min gerbil cerebral ischemia. Gerbils were given MK-801(3 mg/kg i.p.)or saline immediately after the occlusion. On day 4 after reperfusion, neuronal damage was examined in the hippocampus (30 μm)and striatum slices (5 μm)stained with hematoxylin/eosin, fluorescent Nissl staining and membrane tracer DiI. The striatum and C3 regions of the hippocampus were analyzed by confocal microscopy. Neuroprotection was determined by quantifying the degree of cell loss, reduction of morphologically damaged cells, and the degree of preservation of recog-nizable neuroanatomical pathways after the ischemic insult. Our results demonstrate that the neuronal damage induced by sustained ischemia is related to abnormalities in glutamatergic function associated with NMDA receptors. MK-801significantly prevented neuronal loss in the tested brain structures. All of this contributes to a better understanding of the given pathophysiological process causing ischemic neuronal damage.
Effect of policosanol on cerebral ischemia in Mongolian gerbils
Molina, V.;Arruzazabala, M.L.;Carbajal, D.;Valdés, S.;Noa, M.;Más, R.;Fraga, V.;Menéndez, R.;
Brazilian Journal of Medical and Biological Research , 1999, DOI: 10.1590/S0100-879X1999001000014
Abstract: policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane wax, whose main component is octacosanol. an inhibitory effect of policosanol on platelet aggregation and cerebral ischemia in animal models has been reported. thus, the objective of the present study was to evaluate the effect of policosanol on cerebral ischemia induced by unilateral carotid ligation and bilateral clamping and recirculation in mongolian gerbils. policosanol (200 mg/kg) administered immediately after unilateral carotid ligation and at 12- or 24-h intervals for 48 h significantly inhibited mortality and clinical symptoms when compared with controls, whereas lower doses (100 mg/kg) were not effective. control animals showed swelling (tissue vacuolization) and necrosis of neurons in all areas of the brain studied (frontal cortex, hippocampus, striatum and olfactory tubercle), showing a similar injury profile. in the group treated with 200 mg/kg policosanol swelling and necrosis were significantly reduced when compared with the control group. in another experimental model, comparison between groups showed that the brain water content of control gerbils (n = 15) was significantly higher after 15 min of clamping and 4 h of recirculation than in sham-operated animals (n = 13), whereas policosanol (200 mg/kg) (n = 19) significantly reduced the edema compared with the control group, with a cerebral water content identical to that of the sham-operated animals. camp levels in the brain of control-ligated mongolian gerbils (n = 8) were significantly lower than those of sham-operated animals (n = 10). the policosanol-treated group (n = 10) showed significantly higher camp levels (2.68 pmol/g of tissue) than the positive control (1.91 pmol/g of tissue) and similar to those of non-ligated gerbils (2.97 pmol/g of tissue). in conclusion, our results show an anti-ischemic effect of policosanol administered after induction of cerebral ischemia, in two different experimental models i
Determination of interhemispheric neuroprotective action of the cognitive enhancer Phenibute at an experimental ischemic stroke in Gerbils  [PDF]
Mamchur V.I.,Zhuravel’ N.V.
Морфолог?я , 2008,
Abstract: In experiments on Mongolian gerbils the study of neuroprotective properties of the cognitive enhancer Phenibute was conducted. Pathology was studied on the generally accepted model for this type of laboratory animals taking into account the features of the cerebral blood circulation (ischemia and reperfusion). The influence of preparation was explored on the terms of regress of neurological deficit in gerbils with the hemispheric localization of ischemic strokes. A neuromorphological study is conducted influence of nootrop on renewal of nervous fabric in the early terms of ischemia. On the 4th days of ischemia the morphological and functional condition of neurons and maintenance of РNA in them was studied. Some interhemispheric influencing distinctions of Phenibute on renewal of neurons of bark right and left hemispheres were sited. A tendency is exposed to more effective renewals of nervous fabric of right hemisphere under influencing of Phenibute at pres-ence of symmetric hearths of cerebral infarct. Findings can be used for development of rational charts of treatment of pathol-ogy of brain with hemispheric localization.
Delayed treatment with nimesulide reduces measures of oxidative stress following global ischemic brain injury in gerbils  [PDF]
E. Candelario-Jalil,D. Alvarez,N. Merino,O. S. Leon
Quantitative Biology , 2007,
Abstract: Metabolism of arachidonic acid by cyclooxygenase is one of the primary sources of reactive oxygen species in the ischemic brain. Neuronal overexpression of cyclooxygenase-2 has recently been shown to contribute to neurodegeneration following ischemic injury. In the present study, we examined the possibility that the neuroprotective effects of the cyclooxygenase-2 inhibitor nimesulide would depend upon reduction of oxidative stress following cerebral ischemia. Gerbils were subjected to 5 min of transient global cerebral ischemia followed by 48 h of reperfusion and markers of oxidative stress were measured in hippocampus of gerbils receiving vehicle or nimesulide treatment at three different clinically relevant doses (3, 6 or 12 mg/kg). Compared with vehicle, nimesulide significantly (P<0.05) reduced hippocampal glutathione depletion and lipid peroxidation, as assessed by the levels of malondialdehyde (MDA), 4-hydroxy-alkenals (4-HDA) and lipid hydroperoxides levels, even when the treatment was delayed until 6 h after ischemia. Biochemical evidences of nimesulide neuroprotection were supported by histofluorescence findings using the novel marker of neuronal degeneration Fluoro-Jade B. Few Fluoro-Jade B positive cells were seen in CA1 region of hippocampus in ischemic animals treated with nimesulide compared with vehicle. These results suggest that nimesulide may protect neurons by attenuating oxidative stress and reperfusion injury following the ischemic insult with a wide therapeutic window of protection.
The protective effect of M40401, a superoxide dismutase mimetic, on post-ischemic brain damage in Mongolian gerbils  [cached]
Mollace Vincenzo,Iannone Michelangelo,Muscoli Carolina,Palma Ernesto
BMC Pharmacology , 2003, DOI: 10.1186/1471-2210-3-8
Abstract: Background Overproduction of free radical species has been shown to occur in brain tissues after ischemia-reperfusion injury. However, most of free radical scavengers known to antagonize oxidative damage (e.g. superoxide dismutase, catalase), are unable to protect against ischemia-reperfusion brain injury when given in vivo, an effect mainly due to their difficulty to gain access to brain tissues. Here we studied the effect of a low molecular weight superoxide dismutase mimetic (M40401) in brain damage subsequent to ischemia-reperfusion injury in Mongolian gerbils. Results In animals undergoing ischemia-reperfusion injury, neuropathological and ultrastructural changes were monitored for 1–7 days either in the presence or in the absence of M40401 after bilateral common carotid artery occlusion (BCCO). Administration of M40401 (1–40 mg/kg, given i.p. 1 h after BCCO) protected against post-ischemic, ultrastructural and neuropathological changes occurring within the hippocampal CA1 area. The protective effect of M40401 was associated with a significant reduction of the levels of malondialdehyde (MDA; a marker of lipid peroxidation) in ischemic brain tissues after ischemia-reperfusion. Conclusion Taken together, these results demonstrate that M40401 provides protective effects when given early after the induction of ischemia-reperfusion of brain tissues and suggest the possible use of such compounds in the treatment of neurological dysfunction subsequent to cerebral flow disturbances.
50Hz Extremely Low Frequency Electromagnetic Fields Enhance Protein Carbonyl Groups Content in Cancer Cells: Effects on Proteasomal Systems
A. M. Eleuteri,M. Amici,L. Bonfili,V. Cecarini,M. Cuccioloni,S. Grimaldi,L. Giuliani,M. Angeletti,E. Fioretti
Journal of Biomedicine and Biotechnology , 2009, DOI: 10.1155/2009/834239
Abstract: Electromagnetic fields are an assessed cause of prolonging free radicals lifespan. This study was carried out to investigate the influence of extremely low frequency electromagnetic fields on protein oxidation and on the 20S proteasome functionality, the complex responsible for the degradation of oxidized proteins. Caco 2 cells were exposed, for 24–72 hours, to 1 mT, 50 Hz electromagnetic fields. The treatment induced a time-dependent increase both in cell growth and in protein oxidation, more evident in the presence of TPA, while no changes in cell viability were detected. Exposing the cells to 50 Hz electromagnetic fields caused a global activation of the 20S proteasome catalytic components, particularly evident at 72 hours exposure and in the presence of TPA. The finding that EGCG, a natural antioxidant compound, counteracted the field-related pro-oxidant effects demonstrates that the increased proteasome activity was due to an enhancement in intracellular free radicals.
EFFECTS OF EXPOSURES TO A MIX OF FAST NEUTRONS AND 50Hz, 0.05mT MAGNETIC FIELD ON RAT TESTES” (IN VIVO STUDY
Fadel Mohammed Ali,Wafaa Nemat Allal Ahmed,Samira Abdel Hamid,Eman Sayed Abd EL–Fattah
Journal of International Dental and Medical Research , 2011,
Abstract: In the present work; the effect of whole body exposure of rats to mixed radiation (MR) from fast neutrons (FN) and 50Hz, 0.05mT magnetic field (MF) on the structural functions of the animal testis were investigated. For this; 100 white albino rats were divided equally into four groups namely A, B, C and D. Animals of group A were used as control, groups B and C were exposed to 50Hz, 0.05mT MF and fission neutrons from 252Cf source at a dose rate 10 μSv/h respectively for a period of 4 weeks at a rate of 8h/day and 5 days/week. Group D was exposed to fission neutrons and MF at the same field strengths and dose rates for the same period as groups B and C. At the end of the exposure period, blood was collected, animals were sacrificed and testes were removed for histopathological examination. The results indicated highly significant decrease (p<0.0001) of testosterone hormone level (THL) in blood for animals from all groups as compared to control. Moreover; highly significant increase (p<0.0001) in the creatine phosphokinase (CPK) enzyme in sera was measured for all exposed animals. Results were analyzed depending on the probable mechanisms of interaction of these types of radiation with biological tissue. It was concluded from the present findings that the induced damage of the testis and the dramatic elevated CPK enzyme levels are higher for exposure to mixed radiation as compared with exposure to a single field.
50hz1.8mt电磁场对成骨细胞增殖与分化成熟影响的波形比较研究  [PDF]
周建?,马慧萍?,陈克明?,葛宝丰?,程国政?,王嘉琪?,韦哲?
生物化学与生物物理进展 , 2011,
Abstract: 在50hz1.8mt的4种不同波形电磁场(electromagneticfields,emfs)中筛选促进体外培养大鼠成骨细胞(ratosteoblasts,rob)增殖与分化成熟的最佳波形.体外分离培养大鼠颅骨成骨细胞,传代后随机分为5组,分别用频率50hz,emfs强度为0mt(对照组)和1.8mt的正弦波、三角波、方波和锯齿波处理rob,30min/(次·天).在磁场处理后4~8天细胞呈现特征样分布.方波促进成骨细胞增殖,正弦波抑制成骨细胞增殖.三角波和正弦波增加alp活性,其中alp染色、茜素红钙化结节染色和胶原ⅰ(collagen-ⅰ)免疫组织化学检测结果与alp活性一致.在emfs处理后的24h、96h和72h后emfs分别提高runx-2、opg和igf基因表达水平,其中尤以正弦波和三角波作用最为显著.上述结果表明:50hz1.8mt方波促进成骨细胞增殖,正弦波抑制成骨细胞增殖.50hz1.8mtemfs能促进体外培养成骨细胞分化成熟,其中尤以正弦波和三角波促进成骨细胞分化成熟作用最为显著.
50Hz0.1mT三角波电磁场提高大鼠峰值骨量  [PDF]
李少锋,陈克明,高玉海,周建,成魁,马小妮,周延锋,石文贵
第三军医大学学报 , 2014,
Abstract: 目的研究50Hz、0.1mT三角波电磁场对大鼠峰值骨量(peakbonemass,PBM)的影响。方法将5周龄的雌性SD大鼠分成对照组和实验组(n=9)。实验组每天使用三角波电磁场处理90min,对照组除不进行磁场干预外其他条件与实验组相同。在磁场处理中的第1、2、3个月末,腹腔麻醉测量骨密度(bonemineraldensity,BMD)。第3个月末心脏取血处死。ELISA试剂盒检测血清中碱性磷酸酶(bonealkalinephosphatase,BALP)、瘦素(leptin,LEP)和抗酒石酸酸性磷酸酶(tartrateresistantacidphosphatase5b,Tracp5b)含量,并进行骨形态计量分析。?结果?实验组在1、2个月末,BMD检测与对照组相比无显著性差异(P>0.05);3个月末,实验组BMD检测与对照组相比有显著性差异(P<0.05)。血清生化检测结果显示实验组ALP含量上升,Tracp5b和LEP含量下降,与对照组相比具有显著性差异(P<0.05)。实验组双荧光间距离和骨小梁宽度均高于对照组,有显著性差异(P<0.05)。结论低频三角波电磁场能够提高大鼠PBM。
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