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1.
Int Rev Neurobiol ; 137: 123-165, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29132541

RESUMO

More than 5.5 million Americans of all ages are suffering from Alzheimer's disease (AD) till today for which no suitable therapy has been developed so far. Thus, there is an urgent need to explore novel therapeutic measures to contain brain pathology in AD. The hallmark of AD includes amyloid-beta peptide (AßP) deposition and phosphorylation of tau in AD brain. Recent evidences also suggest a marked decrease in neurotrophic factors in AD. Thus, exogenous supplement of neurotrophic factors could be one of the possible ways for AD therapy. Human postmortem brain in AD shows alterations in histamine receptors as well, indicating an involvement of the amine in AD-induced brain pathology. In this review, we focused on role of histamine 3 and 4 receptor-modulating drugs in the pathophysiology of AD. Moreover, antibodies to histamine and tau appear to be also beneficial in reducing brain pathology, blood-brain barrier breakdown, and edema formation in AD. Interestingly, TiO2-nanowired delivery of cerebrolysin-a balanced composition of several neurotrophic factors attenuated AßP deposition and reduced tau phosphorylation in AD brain leading to neuroprotection. Coadministration of cerebrolysin with histamine antibodies or tau antibodies has further enhanced neuroprotection in AD. These novel observations strongly suggest a role of nanomedicine in AD that requires further investigation.


Assuntos
Doença de Alzheimer/terapia , Aminoácidos/administração & dosagem , Anticorpos/administração & dosagem , Histamínicos/administração & dosagem , Titânio , Proteínas tau/imunologia , Animais , Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Humanos
2.
Mol Neurobiol ; 52(2): 867-81, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26133300

RESUMO

Military personnel are often subjected to sleep deprivation (SD) during combat operations. Since SD is a severe stress and alters neurochemical metabolism in the brain, a possibility exists that acute or long-term SD will influence blood-brain barrier (BBB) function and brain pathology. This hypothesis was examined in young adult rats (age 12 to 14 weeks) using an inverted flowerpot model. Rats were placed over an inverted flowerpot platform (6.5 cm diameter) in a water pool where the water levels are just 3 cm below the surface. In this model, animals can go to sleep for brief periods but cannot achieve deep sleep as they would fall into water and thus experience sleep interruption. These animals showed leakage of Evans blue in the cerebellum, hippocampus, caudate nucleus, parietal, temporal, occipital, cingulate cerebral cortices, and brain stem. The ventricular walls of the lateral and fourth ventricles were also stained blue, indicating disruption of the BBB and the blood-cerebrospinal fluid barrier (BCSFB). Breakdown of the BBB or the BCSFB fluid barrier was progressive in nature from 12 to 48 h but no apparent differences in BBB leakage were seen between 48 and 72 h of SD. Interestingly, rats treated with metal nanoparticles, e.g., Cu or Ag, showed profound exacerbation of BBB disruption by 1.5- to 4-fold, depending on the duration of SD. Measurement of plasma and brain serotonin showed a close correlation between BBB disruption and the amine level. Repeated treatment with the serotonin 5-HT3 receptor antagonist ondansetron (1 mg/kg, s.c.) 4 and 8 h after SD markedly reduced BBB disruption and brain pathology after 12 to 24 h SD but not following 48 or 72 h after SD. However, TiO2-nanowired ondansetron (1 mg/kg, s.c) in an identical manner induced neuroprotection in rats following 48 or 72 h SD. However, plasma and serotonin levels were not affected by ondansetron treatment. Taken together, our observations are the first to show that (i) SD could induce BBB disruption and brain pathology, (ii) nanoparticles exacerbate SD-induced brain damage, and (iii) serotonin 5-HT3 receptor antagonist ondansetron is neuroprotective in SD that is further potentiated byTiO2-nanowired delivery, not reported earlier.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Edema Encefálico/prevenção & controle , Cobre/toxicidade , Nanopartículas/toxicidade , Fármacos Neuroprotetores/farmacologia , Ondansetron/farmacologia , Agonistas do Receptor 5-HT3 de Serotonina/farmacologia , Prata/toxicidade , Privação do Sono/fisiopatologia , Animais , Proteínas Sanguíneas/metabolismo , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Encéfalo/fisiopatologia , Química Encefálica/efeitos dos fármacos , Edema Encefálico/etiologia , Edema Encefálico/fisiopatologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/prevenção & controle , Corantes/farmacocinética , Cobre/administração & dosagem , Avaliação Pré-Clínica de Medicamentos , Implantes de Medicamento , Azul Evans/farmacocinética , Fadiga/etiologia , Fadiga/fisiopatologia , Fadiga/prevenção & controle , Radioisótopos do Iodo/farmacocinética , Masculino , Nanofios , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/uso terapêutico , Ondansetron/administração & dosagem , Ondansetron/uso terapêutico , Ratos , Ratos Sprague-Dawley , Teste de Desempenho do Rota-Rod , Transtornos de Sensação/etiologia , Transtornos de Sensação/fisiopatologia , Transtornos de Sensação/prevenção & controle , Serotonina/análise , Agonistas do Receptor 5-HT3 de Serotonina/administração & dosagem , Agonistas do Receptor 5-HT3 de Serotonina/uso terapêutico , Prata/administração & dosagem , Privação do Sono/complicações , Fatores de Tempo
3.
Mol Neurobiol ; 52(2): 882-98, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26126513

RESUMO

Increased levels of ubiquitin and heat shock protein (HSP) 72 kD are often seen in spinal cord injury (SCI). However, their roles in cell injury or survival are not well known. Thus, we have investigated the possible relationship between ubiquitin and HSP expressions in relation to cell injury in healthy animals, or following nanoparticle (NP) intoxication in SCI animals. A focal SCI was inflicted on the T10-11 segments over the right dorsal horn; animals were allowed to survive from 5 to 8 h after trauma. Separate groups of rats were exposed to SiO2, Ag, or Cu NPs for 7 days and subjected to SCI on the eighth day. A marked increase in ubiquitin or HSP immunoreactive cells occurred in the T9 to T12 segments 5 h after the injury, which further extended to the T4 and L5 after 8 h of survival. At this time, a marked increase in blood-spinal cord barrier (BSCB) permeability to Evans blue and radioiodine, accompanied by an intense edema formation, was observed. Changes were further exacerbated in NP-treated traumatized rats. The most marked expressions of ubiquitin and HSP in SCI were seen in rats treated with SiO2, followed by Ag, and Cu NPs. Treatment with H-290/51 (50 mg/kg p.o., 30 to 60 min after injury) or carfilzomib (1 mg/kg, i.v., 30 to 60 min after trauma) significantly reduced the ubiquitin or HSP expressions, as well as the BSCB breakdown, the edema formation, and the cell injury in the cord both 5 and 8 h after the injury, in normal animals. However, a double dose of H-290/51 (100 mg/kg) or carfilzomib (2 mg/kg) is needed to reduce cord pathology or ubiquitin and HSP expressions in traumatized animals treated with NPs. H-290/51 showed superior beneficial effects in reducing cord pathology in SCI than carfilzomib. These observations are the first to demonstrate that (i) NP-treated traumatized animals induce a widespread BSCB leakage, edema formation, and cord pathology as well as an overexpression of ubiquitin and HSP, (ii) high doses of antioxidant compounds or proteasome inhibitors are required for neuroprotection in the NP-exposed traumatized group, and (iii) ubiquitin and HSP expressions play a key role in neuronal injury in SCI, not reported earlier.


Assuntos
Antioxidantes/uso terapêutico , Cobre/toxicidade , Proteínas de Choque Térmico HSP72/biossíntese , Indóis/uso terapêutico , Nanopartículas/toxicidade , Proteínas do Tecido Nervoso/biossíntese , Fármacos Neuroprotetores/uso terapêutico , Oligopeptídeos/uso terapêutico , Inibidores de Proteassoma/uso terapêutico , Prata/toxicidade , Traumatismos da Medula Espinal/tratamento farmacológico , Ubiquitina/biossíntese , Animais , Antioxidantes/farmacologia , Cobre/administração & dosagem , Avaliação Pré-Clínica de Medicamentos , Edema/etiologia , Edema/prevenção & controle , Proteínas de Choque Térmico HSP72/genética , Indóis/farmacologia , Masculino , Proteínas do Tecido Nervoso/genética , Fármacos Neuroprotetores/farmacologia , Oligopeptídeos/farmacologia , Inibidores de Proteassoma/farmacologia , Ratos , Ratos Wistar , Dióxido de Silício/administração & dosagem , Dióxido de Silício/toxicidade , Prata/administração & dosagem , Medula Espinal/metabolismo , Medula Espinal/patologia , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/etiologia , Traumatismos da Medula Espinal/metabolismo , Vértebras Torácicas , Ubiquitina/genética , Regulação para Cima
4.
Mol Neurobiol ; 52(2): 837-45, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26126514

RESUMO

Previous studies from our laboratory showed that topical application of growth hormone (GH) induced neuroprotection 5 h after spinal cord injury (SCI) in a rat model. Since nanodelivery of drugs exerts superior neuroprotective effects, a possibility exists that nanodelivery of GH will induce long-term neuroprotection after a focal SCI. SCI induces GH deficiency that is coupled with insulin-like growth factor-1 (IGF-1) reduction in the plasma. Thus, an exogenous supplement of GH in SCI may enhance the IGF-1 levels in the cord and induce neuroprotection. In the present investigation, we delivered TiO2-nanowired growth hormone (NWGH) after a longitudinal incision of the right dorsal horn at the T10-11 segments in anesthetized rats and compared the results with normal GH therapy on IGF-1 and GH contents in the plasma and in the cord in relation to blood-spinal cord barrier (BSCB) disruption, edema formation, and neuronal injuries. Our results showed a progressive decline in IGF-1 and GH contents in the plasma and the T9 and T12 segments of the cord 12 and 24 h after SCI. Marked increase in the BSCB breakdown, as revealed by extravasation of Evans blue and radioiodine, was seen at these time points after SCI in association with edema and neuronal injuries. Administration of NWGH markedly enhanced the IGF-1 levels and GH contents in plasma and cord after SCI, whereas normal GH was unable to enhance IGF-1 or GH levels 12 or 24 h after SCI. Interestingly, NWGH was also able to reduce BSCB disruption, edema formation, and neuronal injuries after trauma. On the other hand, normal GH was ineffective on these parameters at all time points examined. Taken together, our results are the first to demonstrate that NWGH is quite effective in enhancing IGF-1 and GH levels in the cord and plasma that may be crucial in reducing pathophysiology of SCI.


Assuntos
Hormônio do Crescimento/uso terapêutico , Fator de Crescimento Insulin-Like I/análise , Nanofios , Fármacos Neuroprotetores/uso terapêutico , Traumatismos da Medula Espinal/tratamento farmacológico , Administração Tópica , Animais , Sistemas de Liberação de Medicamentos , Implantes de Medicamento , Edema/etiologia , Edema/prevenção & controle , Azul Evans/farmacocinética , Hormônio do Crescimento/administração & dosagem , Hormônio do Crescimento/análise , Hormônio do Crescimento/farmacocinética , Bombas de Infusão , Infusão Espinal , Radioisótopos do Iodo/farmacocinética , Masculino , Neurônios/patologia , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/farmacocinética , Permeabilidade , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/análise , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/uso terapêutico , Medula Espinal/irrigação sanguínea , Medula Espinal/química , Medula Espinal/patologia , Traumatismos da Medula Espinal/sangue , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/fisiopatologia , Vértebras Torácicas
5.
Mol Neurobiol ; 52(2): 1043-53, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26108181

RESUMO

The possibility that ubiquitin expression is altered in cardiac arrest-associated neuropathology was examined in a porcine model using immunohistochemical and biochemical methods. Our observations show that cardiac arrest induces progressive increase in ubiquitin expression in the cortex and hippocampus in a selective and specific manner as compared to corresponding control brains using enzyme-linked immunoassay technique (enzyme-linked immunosorbent assay (ELISA)). Furthermore, immunohistochemical studies showed ubiquitin expression in the neurons exhibiting immunoreaction in the cytoplasm and karyoplasm of distorted or damaged cells. Separate Nissl and ubiquitin staining showed damaged and distorted neurons and in the same cortical region ubiquitin expression indicating that ubiquitin expression after cardiac arrest represents dying neurons. The finding that methylene blue treatment markedly induced neuroprotection following identical cardiac arrest and reduced ubiquitin expression strengthens this view. Taken together, our observations are the first to show that cardiac arrest enhanced ubiquitin expression in the brain that is related to the magnitude of neuronal injury and the finding that methylene blue reduced ubiquitin expression points to its role in cell damage, not reported earlier.


Assuntos
Barreira Hematoencefálica , Córtex Cerebral/patologia , Parada Cardíaca/metabolismo , Hipocampo/patologia , Proteínas do Tecido Nervoso/biossíntese , Neurônios/metabolismo , Ubiquitina/biossíntese , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Tronco Encefálico/metabolismo , Tronco Encefálico/patologia , Reanimação Cardiopulmonar , Córtex Cerebral/metabolismo , Regulação da Expressão Gênica , Parada Cardíaca/tratamento farmacológico , Parada Cardíaca/patologia , Parada Cardíaca/terapia , Hipocampo/metabolismo , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Proteínas do Tecido Nervoso/genética , Neurônios/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Distribuição Aleatória , Albumina Sérica/análise , Sus scrofa , Suínos , Tálamo/metabolismo , Tálamo/patologia , Ubiquitina/genética , Regulação para Cima
6.
Mol Neurobiol ; 52(2): 899-912, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26108180

RESUMO

Cerebrolysin is a peptide mixture able to ameliorate symptomatology and delay progression of neurological disorders such as Alzheimer's disease and dementia. The administration of this drug in humans presents several criticisms due to its short half-life, poor stability, and high doses needed to achieve the effect. This paper investigates the potential of polylactic-co-glycolide (PLGA) nanoparticles (NPs) as sustained release systems for iv administration of cerebrolysin in normal and brain injured rats. NPs were prepared by water-in-oil-in-water (w/o/w) double emulsion technique and characterized by light scattering for mean size and zeta potential and by scanning electron microscopy (SEM) for surface morphology. The NPs produced by double sonication under cooling at 60 W for 45 s, 12 mL of 1 % w:v of PVA, and 1:0.6 w:w drug/PLGA ratio (C-NPs4) displayed an adequate loading of drug (24 ± 1 mg/100 mg of NPs), zeta potential value (-13 mV), and average diameters (ranged from 250 to 330 nm) suitable to iv administration. SEM images suggested that cerebrolysin was molecularly dispersed into matricial systems and partially adhered to the NP surface. A biphasic release with an initial burst effect followed by sustained release over 24 h was observed. Long-term stability both at room and at low temperature of freeze-dried NPs was investigated. To gain deeper insight into NP stability after in vivo administration, the stability of the best NP formulation was also tested in serum. These PLGA NPs loaded with cerebrolysin were able to reduce brain pathology following traumatic brain injury. However, the size, the polydispersivity, and the surface properties of sample were significantly affected by the incubation time and the serum concentration.


Assuntos
Aminoácidos/administração & dosagem , Lesões Encefálicas/tratamento farmacológico , Ácido Láctico , Nanopartículas , Fármacos Neuroprotetores/administração & dosagem , Ácido Poliglicólico , Aminoácidos/sangue , Aminoácidos/química , Aminoácidos/uso terapêutico , Animais , Barreira Hematoencefálica , Edema Encefálico/etiologia , Edema Encefálico/fisiopatologia , Lesões Encefálicas/complicações , Lesões Encefálicas/fisiopatologia , Preparações de Ação Retardada , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Emulsões , Liofilização , Interações Hidrofóbicas e Hidrofílicas , Masculino , Microscopia Eletrônica de Varredura , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/ultraestrutura , Fármacos Neuroprotetores/sangue , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/uso terapêutico , Concentração Osmolar , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Trealose/química
7.
Artigo em Inglês | MEDLINE | ID: mdl-24069047

RESUMO

With laminectomy being widely accepted as the treatment for lumbar disorders, epidural fibrosis (EF) is a common complication for both the patients and the surgeons alike. Currently, EF is thought to cause recurrent postoperative pain after laminectomy or after discectomy. Angelica sinensis is a traditional Chinese medicine which has shown anti-inflammatory, antifibrotic, and antiproliferative properties. The object of this study was to investigate the effects of Angelica sinensis on the prevention of post-laminectomy EF formation in a rat model. A controlled double-blinded study was conducted in sixty healthy adult Wistar rats that underwent laminectomy at the L1-L2 levels. They were divided randomly into 3 groups according to the treatment method, with 20 in each group: (1) Angelica sinensis treatment group, (2) saline treatment group, and (3) sham group (laminectomy without treatment). All rats were euthanized humanely 4 weeks after laminectomy. The hydroxyproline content, Rydell score, vimentin cells density, fibroblasts density, inflammatory cells density, and inflammatory factors expressions all suggested better results in Angelica sinensis group than the other two groups. Topical application of Angelica sinensis could inhibit fibroblasts proliferation and TGF- ß 1 and IL-6 expressions and prevent epidural scar adhesion in postlaminectomy rat model.

8.
Amino Acids ; 45(5): 1055-71, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24022705

RESUMO

Recent advancement in nanomedicine suggests that nanodrug delivery using nanoformulation of drugs or use of nanoparticles for neurodiagnostic and/or neurotherapeutic purposes results in superior effects than the conventional drugs or parent compounds. This indicates a bright future for nanomedicine in treating neurological diseases in clinics. However, the effects of nanoparticles per se in inducing neurotoxicology by altering amino acid neurotransmitters, if any, are still being largely ignored. The main aim of nanomedicine is to enhance the drug availability within the central nervous system (CNS) for greater therapeutic successes. However, once the drug together with nanoparticles enters into the CNS compartments, the fate of nanomaterial within the brain microenvironment is largely remained unknown. Thus, to achieve greater success in nanomedicine, our knowledge in understanding nanoneurotoxicology in detail is utmost important. In addition, how co-morbidity factors associated with neurological disease, e.g., stress, trauma, hypertension or diabetes, may influence the neurotherapeutic potentials of nanomedicine are also necessary to explore the details. Recent research in our laboratory demonstrated that engineered nanoparticles from metals or titanium nanowires used for nanodrug delivery in laboratory animals markedly influenced the CNS functions and alter amino acid neurotransmitters in healthy animals. These adverse reactions of nanoparticles within the CNS are further aggravated in animals with different co-morbidity factors viz., stress, diabetes, trauma or hypertension. This effect, however, depends on the composition and dose of the nanomaterials used. On the other hand, nanodrug delivery by TiO2 nanowires enhanced the neurotherapeutic potential of the parent compounds in CNS injuries in healthy animals and do not alter amino acids balance. However, in animals with any of the above co-morbidity factors, high dose of nanodrug delivery is needed to achieve some neuroprotection. Taken together, it appears that while exploring new nanodrug formulations for neurotherapeutic purposes, co-morbidly factors and composition of nanoparticlesrequire more attention. Furthermore, neurotoxicity caused by nanoparticles per se following nanodrug delivery may be examined in greater detail with special regards to changes in amino acid balance in the CNS.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Tratamento Farmacológico/instrumentação , Nanomedicina/instrumentação , Nanopartículas/efeitos adversos , Aminoácidos/metabolismo , Animais , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Tratamento Farmacológico/métodos , Humanos , Nanomedicina/métodos , Nanopartículas/química , Nanopartículas/uso terapêutico , Fármacos Neuroprotetores/efeitos adversos , Fármacos Neuroprotetores/uso terapêutico , Neurotransmissores/metabolismo
9.
Ayu ; 33(2): 167-73, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23559784

RESUMO

In the history of Ayurveda, Sushruta stands before Caraka. He practically applied Vaidika culture for treatment. His treatise translated into nine foreign languages apart from various Indian languages like Hindi, Bengali, Malayalam, etc., Sushruta is the most celebrated physician and surgeon in India. Though he practiced during the 5th century BC, many of his contributions to medicine and surgery preceded similar discoveries in the western world. Sushruta devotes a complete volume of his experiences to ophthalmologic diseases. In the Uttara Tantram, Sushruta enumerates a sophisticated classification of eye diseases complete with signs, symptoms, prognosis, and medical/surgical interventions. In particular, Sushruta describes what may have been the first extracapsular cataract surgery using a sharply pointed instrument with a handle fashioned into a trough. His ability to manage many common eye conditions of the time with limited diagnostic aids is a testament to his virtuosity.

10.
Ayu ; 33(4): 491-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23723665

RESUMO

In this part importace and specialize of sushruta are specified. In Part - 1 all the translation works in all the available languages is narrated. After studying all those books and keeping in to mind about a comprehensive work of sushruta it is necessary to elaborate in this present text. This part is divided into 5 sections. (A) All available commentaries taken in to consideration for this part is written, (B) Specialities of sushruta are most important as he has narrated all eight sections of Ayurveda elabroted widely where as caraka has only narrated mainly selected part of kAya-cikitsA and left other sections for other authors e.g., "atra dhAnavantareyaNAM adhikArah" etc., Specifying a list of all sections and chapters with the numbers of prose + poetery, (C) None of the translator or commentator touched the importance of sushruta in the literature of samskRta, where as sushruta was a great poet. Giving similar resemblance of common use by mass, he tried to explain the tough subject in simpler mode of knowledge for proper understanding to all public. He has specifically selected the prosody for the specified subject. Examples are given in this section. (D) sushruta has written prosody in14 metres and long sentences too in samskRta that shows his ability and wast knowledge in the literature. All references of each and every metre is noted from all sections of sushruta with complete reference numbers. And no where this subject is published till now- (E) A challenging word regarding the work of sushruta "shArIre sushruto naSTah" is turned back while quoting various references of shArIra-sthAnam and placing its world wide importance by various writers.

11.
Eur J Neurosci ; 26(5): 1242-53, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17767502

RESUMO

To clarify the role of brain temperature in permeability of the blood-brain barrier (BBB), rats were injected with methamphetamine (METH 9 mg/kg) at normal (23 degrees C) and warm (29 degrees C) environmental conditions and internal temperatures were monitored both centrally (nucleus accumbens, NAcc) and peripherally (skin and nonlocomotor muscle). Once NAcc temperatures peaked or reached 41.5 degrees C (a level suggesting possible lethality), animals were administered Evans blue dye (protein tracer that does not normally cross the BBB), rapidly anaesthetized, perfused and had their brains removed. All METH-treated animals showed brain and body hyperthermia associated with relative skin hypothermia, suggesting metabolic activation coupled with peripheral vasoconstriction. While METH-induced NAcc temperature elevation varied from 37.60 to 42.46 degrees C (or 1.2-5.1 degrees C above baseline), it was stronger at 29 degrees C (+4.13 degrees C) than 23 degrees C (+2.31 degrees C). Relative to control, METH-treated animals had significantly higher brain levels of water, Na(+), K(+) and Cl(-), suggesting brain edema, and intense immunostaining for albumin, indicating breakdown of the BBB. METH-treated animals also showed strong immunoreactivity for glial fibrillary acidic protein (GFAP), possibly suggesting acute abnormality or damage of astrocytes. METH-induced changes in brain water, albumin and GFAP correlated linearly with NAcc temperature (r = 0.93, 0.98 and 0.98, respectively), suggesting a key role of brain hyperthermia in BBB permeability, development of brain edema and subsequent functional and structural neural abnormalities. Therefore, along with a direct destructive action on neural cells and functions, brain hyperthermia, via breakdown of the BBB, may be crucial for both decompensation of brain functions and cell injury following acute METH intoxication, possibly contributing to neurodegeneration resulting from chronic drug use.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Edema Encefálico/induzido quimicamente , Edema Encefálico/fisiopatologia , Estimulantes do Sistema Nervoso Central/farmacologia , Hipertermia Induzida , Metanfetamina/farmacologia , Animais , Barreira Hematoencefálica/efeitos da radiação , Temperatura Corporal , Permeabilidade Capilar/efeitos dos fármacos , Permeabilidade Capilar/fisiologia , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Ratos , Ratos Long-Evans
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