Physicochemical data of oleic acid-poloxamer organogel for intravaginal voriconazole delivery.

Functional polymeric nanoparticles have attracted attention for different biomedical applications, including drug delivery. Poloxamers (PL), a synthetic copolymers of poly(ethyleneoxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), that exhibit thermoreversible behavior in aqueous solutions. Physicochemical properties of Oleic Acid-Poloxamer (OA-PL) organogel for intravaginal controlled Voriconazole (VRC) delivery were assessed using three different oils (isopropyl myristate - IPM, isopropyl palmitate - IPP, and oleic acid - OA, in order to select the most suitable oil phase for increasing the solubility of the drug and its dispersion in the final aqueous phase. Organogel structural organization was assessed by VRC partition coefficient, differential scanning calorimetry (DSC), rheological analysis, and drug release assay. These data are complementary to the research article entitled "Sodium alginate in oil-poloxamer organogels for intravaginal drug delivery: influence on structural parameters, drug release mechanisms, cytotoxicity and in vitro antifungal activity" - Materials Science and Engineering: C, 2019. 99: p. 1350-1361.

Sodium alginate in oil-poloxamer organogels for intravaginal drug delivery: Influence on structural parameters, drug release mechanisms, cytotoxicity and in vitro antifungal activity.

Local administration of antimicrobial agents is the first therapeutic approach for the treatment of Candida albicans infections. The duration of contact of formulations with the vaginal mucosa is critical for therapeutic efficacy. This study describes the development of organogels employing an oil phase composed of oleic acid (OA) and an aqueous phase consisting of the poloxamer PL407, alone or in association with PL188, together with 0.25-1% sodium alginate (SA), in order to obtain an intravaginal drug delivery system capable of modulating the release of voriconazole (VRC). VRC was solubilized in oleic acid homogenized with the PL-SA aqueous phase, at a final concentration of 5 mg/mL. Physicochemical characterization was performed for evaluation of the influence of SA on organogel structural organization, biopharmaceutical properties, pharmacological efficacy, and cytotoxicity, envisaging use of the formulation for the treatment of vaginal candidiasis. The enthalpy variation values showed greater changes in the presence of PL188 and after the incorporation of SA or VRC in the organogels. Rheological analysis showed Tsol-gel values in the ranges 11-39 °C and 27-30 °C for the OA-PL407 and OA-PL407-188 formulations, respectively. Oscillatory analysis of OA-PL407-188 showed that G' was ~20-fold higher than G″, even after submitting the formulation to temperature variation. VRC-OA-PL407 showed fast drug release from 0.5 to 4 h, maintaining total release (~100%) up to 24 h. The incorporation of SA in the organogels enabled modulation of VRC release, with different release percentages for 0.25% SA (~75%), 0.5% SA (~55%), and 1% SA (~35%). The formulation was non-cytotoxic towards HeLa and Vero cell lines. In diffusion tests, it was able to prevent the growth of Candida albicans and Candida krusei. In conclusion, the results suggested that OA-PL407-188-SA organogels could be possible new systems for VRC delivery, with potential for use in future vaginal applications.

The Organochalcogen Compound (MeOPhSe)2 Inhibits Both Formation and the Viability of the Biofilm Produced by Candida albicans, at Different Stages of Development.

BACKGROUND: Candida albicans is a commensal and opportunistic fungus which is able to produce both local and systemic infections in immunocompromised patients. A correlation has been demonstrated between the resistance to conventional antifungal drugs and C. albicans ability to produce biofilms. Therefore, the potential of the organochalcogen compounds as antifungal therapy has been demonstrated. METHOD: In this work, we studied the effect of the organochalcogen compound (MeOPhSe)2 on both formation and the viability of the biofilm produced by C. albicans, at different stages of development. Biofilm formation and viability were determined by a metabolic assay based on the reduction of XTT assay. In addition, the morphology of the biofilm was observed using light microscopy. RESULTS: A significant reduction was observed in both growth and biofilm formation by C. albicans, in a dependent manner of cell density. In the presence of 2 µM (MeOPhSe)2 it was observed an inhibition of 87, 72, 69 and 56 % in C. albicans growth, using cell densities of 104, 105, 106 and 107 cells/mL, respectively. C. albicans growth was inhibited >90 % in the presence of 10 µM (MeOPhSe)2 in all cell densities used. Also, (MeOPhSe)2 was found to be able to decrease the viability of the biofilm produced by C. albicans at different stages of development. This effect was more pronounced in early biofilms as compared to mature biofilms. Biofilms forming at 6 and 12 hours was inhibited ~80% in the presence of 10 µM (MeOPhSe)2. However, mature biofilms presented an inhibition of ~40 % in the presence of 10 µM (MeOPhSe)2. The analyses of the structure of the biofilm have shown a significant reduction in the number of both yeast and filamentous form after treatment with (MeOPhSe)2. In addition, the organochalcogen compound (MeOPhSe)2 did not modify the viability of Fibroblastic cells. CONCLUSION: Taken together, these results demonstrated the potential of the organochalcogen compound (MeOPhSe) 2 as a promising antifungal therapy.

Expression of mPGES-1 and IP mRNA is reduced by LLLT in both subplantar and brain tissues in the model of peripheral inflammation induced by carrageenan.

The increase in PGE2 production by microsomal PGE synthase-1 (mPGES-1) in CNS contributes to the severity of the inflammatory and pain responses in the model of edema formation and hyperalgesia induced by carrageenan. PGI2, alike to PGE2, plays an important role in the inflammation. Low-level laser therapy (LLLT) has been used in the treatment of inflammatory pathologies, reducing both pain and the acute inflammatory process. In this work, we studied the effect of LLLT on the expression of both mPGES-1 and IP messenger RNA (mRNA), in either subplantar or total brain tissues obtained from rats submitted to model of edema formation and hyperalgesia induced by carrageenan administration. The test sample consisted of 30 rats divided into five groups: A1 (control-saline), A2 (carrageenan-0.5 mg/paw), A3 (carrageenan-0.5 mg/paw + LLLT), A4 (carrageenan-1.0 mg/paw), and A5 (carrageenan-1.0 mg/paw + LLLT). The animals from groups A3 and A5 were irradiated 1 h after induction of inflammation by carrageenan injection. Continuous-wave red laser with wavelengths of 660 nm and dose of 7.5 J/cm(2) was used. Six hours after carrageenan-induced inflammation, mPGES-1 and prostacyclin receptor (IP) mRNA expression were significantly increased both in subplantar and brain tissues. LLLT was able to reduce both mPGES-1 and IP mRNA expression in subplantar and brain tissues. We suggest that LLLT is able to reduce both inflammation and hyperalgesia observed in the model of edema formation and hyperalgesia induced by carrageenan, by a mechanism involving the decrease in the expression of both mPGES-1 and IP.

Antioxidant properties of diorganoyl diselenides and ditellurides: modulation by organic aryl or naphthyl moiety.

Diorganoyl dichalcogenide compouds can have antioxidant activity in different in vitro and in vivo models. Here, we have compared the potential antioxidant activity of 1-dinaphthyl diselenide (1-NapSe)(2), 2-dinaphthyl diselenide (2-NapSe)(2), 1-dinaphthyl distelluride (1-NapTe)(2), 2-dinaphthyl ditelluride (2-NapTe)(2) with their well-studied analogs diphenyl diselenide ((PhSe)(2)) and diphenyl telluride ((PhTe)(2)). (PhSe)(2), (PhTe)(2), and naphthalene analogs-inhibited Fe(II)-induced lipid peroxidation, catalytically decomposed hydrogen peroxide and oxidized thiols, such as dithiothreitol (DTT), Cysteine (CYS), dimercaptopropionic acid (DMPS), and thiophenol (PhSH). (PhSe)(2) was the less potent of the tested compounds against Fe(II)-induced lipid peroxidation in brain homogenates and the change in the organic moiety from an aryl to naphthyl group increased considerably the antioxidant potency of diselenide compounds. However, the change from aryl to naphthyl had little effect on the thio-peroxidase-like activity of diorganoyl dichalcogenides. These results suggest that minor changes in the organic moiety of aromatic diselenide compounds can modify profoundly their capacity to inhibit iron-induced lipid peroxidation. The pharmacological properties of organochalcogens are thought to be linked to their capacity of modulating oxidative stress. Consequently, it becomes important to explore the toxicological properties of dinaphthyl diselenides and ditellurides.

Anti-inflammatory action of the Ovis aries lipidic fraction associated to therapeutic ultrasound in an experimental model of tendinitis in rats (Rattus norvegicus).

BACKGROUND: Studies have demonstrated the beneficial effects of topical application of fatty acids as healing agents. The lipid fraction of Ovis aries have an anti-inflammatory action that accelerates the healing process. Ultrasound increases blood flow and the extensibility of collagen structures and tendons. OBJECTIVES: To assess the anti-inflammatory action of the Ovis aries lipid fraction associated to pulsed therapeutic ultrasound and friction in an induced tendinitis model. METHODS: Fifty Wistar rats were divided into four groups: control that consisted of Ovis aries gel for topical use; pulsed ultrasound plus oil free sterile lotion; pulsed ultrasound plus Ovis aries gel; and oil free sterile lotion for topical use alone. To induce tendinitis a 10 µL intratendinous injection of collagenase was injected into the right Achilles tendon of rats. Treatment consisted of daily applications of ultrasound using the following parameters: 10% pulsed mode, 10% pulsed frequency of 1 MHz and intensity of 0.5 W/cm² for seven or fourteen days. RESULTS: After 7 days of treatment, only the Ovis aries plus ultrasound group showed statistically significant difference when compared to the control group.The variation in the number of inflammatory cells on animals treated for fourteen days for the control, ultrasound plus oil free, ultrasound plus Ovis aries, Ovis aries plus massage and massage plus oil free groups were statistically significant different, p<0.01. It was observed in animals treated for seven days that the ultrasound plus Ovis aries group was statistically significant better than the control group, p<0.05. CONCLUSION: It can be concluded that treatment using ultrasound plus Ovis aries is more effective than other treatments as it produces significantly better reduction on the number of inflammatory cells at 7 and 14 days.

Ação anti-inflamatória da fração lipídica do Ovis aries associado ao ultrassom terapêutico em modelo experimental de tendinite em ratos (Rattus norvegicus) / Anti-inflammatory action of the Ovis aries lipidic fraction associated to therapeutic ultrasound in an experimental model of tendinitis in rats (Rattus norvegicus)

CONTEXTUALIZAÇÃO: Estudos demonstram o efeito benéfico da aplicação tópica de ácidos graxos como agentes cicatrizantes. A fração lipídica do Ovis aries apresenta uma ação anti-inflamatória que acelera o processo de cicatrização. O ultrassom aumenta o fluxo sanguíneo bem como a extensibilidade das estruturas de colágeno e tendões. OBJETIVOS: Analisar a ação anti-inflamatória da fração lipídica do Ovis aries associado ao ultrassom terapêutico (UST) pulsado e à fricção em modelo de tendinite induzida. MÉTODOS: Cinquenta ratos Wistar foram distribuídos nos seguintes grupos: controle, gel Ovis aries - uso tópico - UST pulsátil + loção estéril (oil free), UST pulsátil + gel Ovis aries, loção estéril (oil free) - uso tópico. Para induzir a tendinite, utilizou-se uma injeção intratendínea de 10µL de colagenase no tendão do calcâneo direito. O tratamento consistiu em aplicações diárias de ultrassom, com os seguintes parâmetros: modo pulsado 10 por cento, frequência de 1 MHz, pulsátil a 10 por cento com intensidade de 0,5W/cm², durante sete ou 14 dias. RESULTADOS: A variação do número de células inflamatórias, para os animais tratados por 14 dias, com relação aos grupos controle, UST + oil free e UST + Ovis aries, apresentou resultados significativos p<0,001. O grupo Ovis aries + massagem e o grupo massagem + oil free apresentaram resultados significativos, p<0,01. Nos animais tratados por sete dias, observou-se que o grupo UST + Ovis aries, em relação ao controle, é estatisticamente significativo, p<0,05 CONCLUSÃO: Pode-se concluir que o tratamento com UST + Ovis aries é mais efetivo que os outros tratamentos, visto que consegue reduzir o número de células inflamatórias no tempo de sete e 14 dias.

BACKGROUND: Studies have demonstrated the beneficial effects of topical application of fatty acids as healing agents. The lipid fraction of Ovis aries have an anti-inflammatory action that accelerates the healing process. Ultrasound increases blood flow and the extensibility of collagen structures and tendons. OBJECTIVES: To assess the anti-inflammatory action of the Ovis aries lipid fraction associated to pulsed therapeutic ultrasound and friction in an induced tendinitis model. METHODS: Fifty Wistar rats were divided into four groups: control that consisted of Ovis aries gel for topical use; pulsed ultrasound plus oil free sterile lotion; pulsed ultrasound plus Ovis aries gel; and oil free sterile lotion for topical use alone. To induce tendinitis a 10µL intratendinous injection of collagenase was injected into the right Achilles tendon of rats. Treatment consisted of daily applications of ultrasound using the following parameters: 10 percent pulsed mode, 10 percent pulsed frequency of 1 MHz and intensity of 0.5 W/cm² for seven or fourteen days. RESULTS: After 7 days of treatment, only the Ovis aries plus ultrasound group showed statistically significant difference when compared to the control group.The variation in the number of inflammatory cells on animals treated for fourteen days for the control, ultrasound plus oil free, ultrasound plus Ovis aries, Ovis aries plus massage and massage plus oil free groups were statistically significant different, p<0.01. It was observed in animals treated for seven days that the ultrasound plus Ovis aries group was statistically significant better than the control group, p<0.05. CONCLUSION: It can be concluded that treatment using ultrasound plus Ovis aries is more effective than other treatments as it produces significantly better reduction on the number of inflammatory cells at 7 and 14 days.

Inhibition of carrageenan-induced expression of tissue and plasma prekallikreins mRNA by low level laser therapy in a rat paw edema model.

BACKGROUND: Low level laser therapy (LLLT) has been used clinically in order to treat inflammation, where tissue and plasma prekallikrein have crucial importance. Plasma prekallikrein (PPK) is synthesized by the hepatocytes and secreted into the bloodstream, where it participates in the surface-dependent activation of blood coagulation, fibrinolysis, kinin generation and inflammation. Tissue prekallikrein is associated with important disease states (including cancer, inflammation, and neurodegeneration) and has been utilized or proposed as clinically important biomarker or therapeutic target of interest. OBJECTIVE: To evaluate if LLLT modulates tissue and plasma prekallikreins mRNA expression in the carrageenan-induced rat paw edema. METHODS: Experimental groups were assigned as followed: A(1) (Control-saline), A(2) (Carrageenan-only), A(3) (laser 660 nm only) and A(4) (Carrageenan + laser 660 nm). Edema was measured by a plethysmometer. Subplantar tissue was collected for the quantification of prekallikreins mRNA by Real time-Polymerase Chain Reaction. RESULTS: A significantly decrease in the edema was observed after laser irradiation. Expression of prekallikreins increased after carrageenan injection. Tissue and plasma prekallikrein mRNA expression significantly decreased after LLLT's 660 nm wavelength. CONCLUSION: These results suggest that expression of tissue and plasma prekallikreins is modulated by LLLT, which can be used in clinical practice due to its anti-inflammatory effects.

Inhibition of carrageenan-induced expression of tissue and plasma prekallikreins mRNA by low level laser therapy in a rat paw edema model / Inibição da expressão de RNA mensageiro de pré-calicreínas tecidual e plasmática pela laserterapia em modelo de edema de pata induzido pela carragenina em ratos

BACKGROND: Low level laser therapy (LLLT) has been used clinically in order to treat inflammation, where tissue and plasma prekallikrein have crucial importance. Plasma prekallikrein (PPK) is synthesized by the hepatocytes and secreted into the bloodstream, where it participates in the surface-dependent activation of blood coagulation, fibrinolysis, kinin generation and inflammation. Tissue prekallikrein is associated with important disease states (including cancer, inflammation, and neurodegeneration) and has been utilized or proposed as clinically important biomarker or therapeutic target of interest. OBJECTIVE: To evaluate if LLLT modulates tissue and plasma prekallikreins mRNA expression in the carrageenan-induced rat paw edema. METHODS: Experimental groups were assigned as followed: A1 (Control-saline), A2 (Carrageenan-only), A3 (laser 660nm only) and A4 (Carrageenan + laser 660nm). Edema was measured by a plethysmometer. Subplantar tissue was collected for the quantification of prekallikreins mRNA by Real time-Polymerase Chain Reaction. RESULTS: A significantly decrease in the edema was observed after laser irradiation. Expression of prekallikreins increased after carrageenan injection. Tissue and plasma prekallikrein mRNA expression significantly decreased after LLLT's 660nm wavelength. CONCLUSION: These results suggest that expression of tissue and plasma prekallikreins is modulated by LLLT, which can be used in clinical practice due to its anti-inflammatory effects.

CONTEXTUALIZAÇÃO: A laserterapia de baixa potência tem sido usada para o tratamento de processos inflamatórios diversos em que a calicreína tecidual e a plasmática possuem participação ativa. A pré-calicreína plasmática (PPK) é sintetizada pelos hepatócitos e secretada na corrente sanguínea, onde participa da ativação da coagulação, fibrinólise, geração de cininas e inflamação. A pré-calicreína tecidual está associada com importantes doenças (incluindo câncer, inflamação e neurodegeneração) e tem sido utilizada ou sugerida clinicamente como importante biomarcador ou alvo terapêutico. OBJETIVO: Avaliar se a laserterapia altera a expressão gênica da pré-calicreína tecidual e da plasmática no modelo de inflamação aguda induzida pela carragenina. MÉTODOS: Quarenta ratos foram separados em quatro grupos experimentais: A1 (controle), A2 (carragenina, apenas), A3 (laser 660nm, apenas) e A4 (Carragenina + laser 660nm). O edema foi medido por um pletismômetro. Tecido subplantar foi coletado para a quantificação de RNA mensageiro (RNAm) de pré-calicreínas tecidual e plasmática por PCR em tempo real. RESULTADOS: Observou-se uma diminuição significativa no volume de edema após irradiação com laser 660nm. A expressão de RNAm de pré-calicreínas tecidual e plasmática aumentou após a inoculação de carragenina, entretanto a expressão gênica das pré-calicreínas diminuiu significantemente após laserterapia de baixa potência de 660nm. CONCLUSÃO: Os resultados sugerem que a expressão de RNAm das pré-calicreínas tecidual e plasmática é modulada pela laserterapia de baixa potência, podendo ser alvo terapêutico para tratamento de processos inflamatórios.

Oral appliance treatment for obstructive sleep apnea in a partly edentulous patient.

INTRODUCTION: We report on the use of an oral appliance fitted to a few maxillary and mandibular teeth to treat obstructive sleep apnea syndrome. METHODS: We used a mandibular repositioning appliance, the adjustable PMPositioner. Polysomnograms were taken before and after use of the appliance. RESULTS: The apnea-hypopnea index decreased from 19.0 to 8.0. Minimum oxygen saturation increased from 80.0% to 86.0%, and rapid eye movement sleep increased from 6.0% to 20.0%, indicating that the device remained in position during sleep. A 2-year follow-up showed that periodontal and gingival health was maintained. CONCLUSIONS: Oral appliances such as the PMPositioner are an alternative for treating obstructive sleep apnea in partly edentulous patients.

Systematic assessment of the impact of oral appliance therapy on the temporomandibular joint during treatment of obstructive sleep apnea: long-term evaluation.

OBJECTIVE: The aim of the present study was to evaluate the symptoms of temporomandibular dysfunction (TMD) in patients with obstructive sleep apnea treated with long-term use of an oral appliance (OA) using a questionnaire based on the Helkimo Anamnestic Dysfunction Index. A further aim of the study was to evaluate the presence of daytime sleepiness using the Epworth Sleep Scale (ESS) and otologic symptoms. MATERIALS AND METHODS: Polysomnograms of 34 patients were performed at baseline and after 6 months of OA use. As follow-up, the patients were contacted by telephone interview to answer the same questionnaires after 36.0 +/- 17.0 months. RESULTS AND DISCUSSION: The intensity of TMD symptoms decreased significantly throughout treatment (p < 0.01). ESS values improved from 12.2 +/- 5.0 to 6.9 +/- 2.6 (p < or = 0.05). Tinnitus was present in nine patients at baseline and decreased in intensity in seven patients by the final assessment while remaining at the same level in two patients. CONCLUSIONS: We conclude that long-term usage of an OA does not cause impairment to the temporomandibular joint. The Helkimo and otologic indexes are simple and useful in long-term patient follow-up. There was a long-term improvement in the ESS values over the years analyzed. A follow-up program could increase compliance by motivating patients to use the device regularly.

Effect of low level laser therapy on bronchial hyper-responsiveness.

The objective of this study was to investigate whether low level laser therapy (LLLT) could reduce bronchial hyper-responsiveness (BHR) induced by tumour necrosis factor-alpha (TNF-alpha) modulating the metabolism of inositol phosphate (IP) in bronchial smooth muscle cells (BSMCs). The study was on 28 Wistar rats, randomly divided into four groups. Irradiation (1.3 J/cm(2)) was administered 5 min and 4 h after bronchial smooth muscle (BSM) had been suspended in TNF-alpha baths, and the contractile response-induced calcium ion (Ca(2+)) sensitization was measured. The BSMCs were isolated, and the IP accumulation was measured before and after TNF-alpha immersion in the groups that had been irradiated or not irradiated. BSM segments significantly increased contraction 24 h after TNF-alpha immersion when exposed to carbachol (CCh) as Ca(2+), but it was significantly reduced by 64% and 30%, respectively, after laser treatment. The increase in IP accumulation induced by CCh after TNF-alpha immersion was reduced in the BSMCs by LLLT. The dose of 2.6 J/cm(2) reduced BHR and IP accumulation in the rats' inflammatory BSMCs.

Use of near-infrared Raman spectroscopy for identification of atherosclerotic plaques in the carotid artery.

OBJECTIVES: The aim of this work was to identify the presence of atherosclerotic plaque in the human carotid artery using near infrared Raman spectroscopy. BACKGROUND DATA: Atherosclerosis is the most common and serious pathology of the cardiovascular system. Raman spectroscopy is an analytical tool that can be used to gather information about both the morphology and chemical composition of tissues. METHODS: A Ti:sapphire laser operating at the near-infrared wavelength of 830 nm pumped by an argon laser was used for excitation of the samples, and the Raman scattering was detected by an optical spectrometer with a liquid-nitrogen-cooled CCD detector. Carotid artery samples were classified into five groups: normal, intimal thickening, fatty plaque, fibrous-fatty plaque, and fibrous-calcified plaque. RESULTS: It was observed that the Raman spectrum of atheromatous plaque was different that that of normal tissue. The spectra of atheromatous plaques had bands due to the presence of cholesterol and its esters, with major bands at 1439 and 1663 cm(1), respectively. In normal tissues a peak related to C-H bending appears at 1451 cm(1). Calcified atheromatous plaques had primary bands at 961 and 1071 cm(1), which were due to the presence of phosphate and carbonate in the accumulated calcium. Peaks were seen at 1451 and 1655 cm(1) in the non-atherosclerotic tissue, which were shifted to 1439 and 1663 cm(1) in the atherosclerotic plaque. CONCLUSIONS: Our results indicate that this technique could be used to detect the presence of atherosclerotic plaques in carotid arterial tissue.

Identification of calcifications in cardiac valves by near infrared Raman spectroscopy.

OBJECTIVE: The objective of this work was to detect calcification in cardiac valves using near infrared Raman spectroscopy (NIRS). A Ti:sapphire laser pumped by an argon-ion laser operating at a wavelength of 830 nm was used for excitation of the valve samples, and Raman emission was detected by an optical spectrometer with a liquid nitrogen-cooled CCD detector. BACKGROUND: Cardiac valves are subjected to highly repetitive mechanical stresses, due to their over 40 million cardiac cycles per year. These structures may suffer cumulative lesions, complicated by the deposition of calcium phosphate, which can lead to clinically significant diseases. NIRS can provide important information about biological tissue composition and has been used for diagnosis of some types of human pathology. METHODS: Samples of normal and pathologic tissues 5 mm in size were analyzed. RESULTS: It was observed that the Raman spectrum of calcified cardiac valves presented different behavior when compared with normal valves. Differences were observed at the intensity of 960, 1,260, 1,452, and 1,660 cm(1) peaks. CONCLUSIONS: These results suggest that this technique could be used to detect calcium phosphate mineral deposition in cardiac valves.

Status epilepticus induced by pilocarpine and Ca2+ transport by microsome in the hippocampus of rats.

An increase in intra-neuronal Ca(2+) concentration has been associated to status epilepticus (SE). Ca(2+) is stored in the endoplasmic reticulum, mediated by the Ca(2+)-ATPases (SERCAs). Here we studied the Ca(2+)-ATPase activity and the SERCA2b distribution in the hippocampus of rats submitted to 5h of SE. The Ca(2+)-uptake was measured using [45Ca]CaCl(2) and the hippocampal distribution of SERCA2b was analyzed by immunohistochemistry. A reduction in the amount of cells expressing SERCA2b in CA1, CA3 and dentate gyrus was observed. However, the surviving cells of these regions increased the SERCA2b immunoreactivity, when compared with control tissues. The Ca(2+)-ATPase activity measured in all hippocampal formation was not modified by SE. These results suggest that SE promotes a redistribution of SERCA2b in the hippocampus as a compensatory Ca(2+)-transport mechanism.

Pilocarpine-induced status epilepticus increases glutamate release in rat hippocampal synaptosomes.

A pronounced glutamate release has been related to neuronal death in several structures due to status epilepticus (SE). We investigated the glutamate uptake and release by both cortical and hippocampal synaptosome in pilocarpine model of epilepsy. Animals were submitted to long-lasting SE (12 h) induced by pilocarpine and compared with non-treated animals. Animals presenting SE did not modify the glutamate uptake by synaptosomes. An increase in the glutamate efflux in the absence (1.43-fold) and in the presence of KCl (1.25-fold) was found in hippocampal synaptosomes. Pilocarpine added to the medium did not modify the glutamate release profile, showing that SE is necessary to modify the glutamate release. As the glutamate uptake is not modified, the hippocampal excitotoxicity may be related to impairment only in the mechanism of the glutamate release.