Antifungal activity of terpenes isolated from the Brazilian Caatinga: a review.

Terpenoids, also named terpenes or isoprenoids, are a family of natural products found in all living organisms. Many plants produce terpenoids as secondary metabolites, and these make up a large part of essential oils. One of most important characteristic is that the compounds are volatile, have odor and can be used in a variety of applications in different industrial segments and traditional medicine. Brazil has a rich and diverse flora that can be used as a source of research for obtaining new molecules. Within the Brazilian flora, it is worth mentioning the Caatinga as an exclusively Brazilian biome where plants adapt to a specific series of weather conditions and therefore become a great storehouse of the terpenoid compounds to be described herein. Fungal infections have become increasingly common, and a great demand for new agents with low toxicity and side effects has thus emerged. Scientists must search for new molecules exhibiting antifungal activity to develop new drugs. This review aims to analyze scientific data from the principal published studies describing the use of terpenes and their biological applications as antifungals.

Antifungal activity of terpenes isolated from the Brazilian Caatinga: a review / Atividade antifúngica de terpenos isolados da Caatinga: uma revisão

Terpenoids, also named terpenes or isoprenoids, are a family of natural products found in all living organisms. Many plants produce terpenoids as secondary metabolites, and these make up a large part of essential oils. One of most important characteristic is that the compounds are volatile, have odor and can be used in a variety of applications in different industrial segments and traditional medicine. Brazil has a rich and diverse flora that can be used as a source of research for obtaining new molecules. Within the Brazilian flora, it is worth mentioning the Caatinga as an exclusively Brazilian biome where plants adapt to a specific series of weather conditions and therefore become a great storehouse of the terpenoid compounds to be described herein. Fungal infections have become increasingly common, and a great demand for new agents with low toxicity and side effects has thus emerged. Scientists must search for new molecules exhibiting antifungal activity to develop new drugs. This review aims to analyze scientific data from the principal published studies describing the use of terpenes and their biological applications as antifungals.

Os terpenóides, também chamados terpenos ou isoprenóides, são uma família de produtos naturais encontrados em todos os organismos vivos. Muitas plantas são produtoras destes metabolitos secundários, que constituem uma grande parte dos óleos essenciais. Uma das características mais importantes é que os compostos são voláteis, têm odor e podem ser utilizados numa variedade de aplicações em diferentes segmentos industriais ou na medicina tradicional. O Brasil tem uma flora rica e diversificada que pode ser utilizada como fonte de pesquisa para a obtenção de novas moléculas. Dentro desta flora, vale a pena mencionar a Caatinga como um bioma exclusivamente brasileiro que possui plantas adaptadas a uma série de condições climáticas e, portanto, um armazém de compostos a serem descritos. As infecções fúngicas são doenças cada vez mais comuns, devido a isso existe uma grande procura de novos agentes com baixa toxicidade e efeitos secundários. Os cientistas devem procurar novas moléculas que exibam atividade antifúngica para o desenvolvimento de novos medicamentos contra as infecções fúngicas. Esta revisão visa analisar dados científicos dos principais estudos publicados que descrevem o uso de terpenóides e as suas aplicações biológicas como antifúngicos.

Avaliação morfológica de plantas jovens de Copaifera langsdorffii Desf. desenvolvidas em diferentes temperaturas / Morphlogical evaluation of Copaifera langsdorffii Desf. saplings grown in different temperatures

O principal objetivo da pesquisa foi a avaliação de aspectos da anatomia foliar, da morfologia dos órgãos vegetativos, bem como a produção de biomassa em plantas jovens de Copaifera langsdorffii desenvolvidas sob diferentes temperaturas. Foram coletadas sementes e colocadas para germinar em câmara BOD a 30ºC. Após trinta dias as plântulas, com o primeiro par de folhas completamente expandidas, foram transplantadas para copos contendo plantimax®, e aclimatizadas durante quinze dias em casa de vegetação, quando foram transferidas para BODs com temperaturas T1-15ºC, T2-25ºC, T3-35ºC, e a testemunha (T) que permaneceu em casa de vegetação (29ºC). O experimento foi conduzido por um período de 120 dias. Foram observadas diferenças significativas no tamanho e frequência dos estômatos, nas dimensões das cavidades secretoras de óleo, na espessura do mesofilo, nos aspectos morfológicos externos, e na produção de biomassa. A produção de mudas sob temperatura de 25ºC foi apropriada, sendo a condição onde as plantas tornaram-se mais vigorosas, com morfologia mais uniforme nos órgãos vegetativos e houve maior produção de biomassa seca.

The main purpose of this study was to evaluate aspects of leaf anatomy, morphology of vegetative organs and biomass production in Copaifera langsdorffii saplings developed under heat shock treatment. Seeds were collected and germinated in BOD chamber at 30 ºC. After thirty days, the seedlings with the first pair of fully expanded leaves were transplanted into cups containing Plantimax®, acclimatized for two weeks in a greenhouse and transferred to growth chamber with the temperatures T1-15 ºC, T2-25 ºC, T3- 35 ºC, and the control (T) remained in a greenhouse (29 ºC). The experiment was conducted over a period of 120 days. Significant differences were observed in size and frequency of stomata, size of the oil secretory cavities, thickness of the mesophyll in the external morphology and biomass production. The production of seedlings at 25 ºC is suitable, a condition in which the plants become more vigorous with a more uniform morphology in the vegetative organs and higher production of biomass.

Chemical composition and antimicrobial activity of the essential oil from the leaves and flowers of Aloysia gratissima / Composição química e atividade antimicrobiana do óleo essencial de folhas e flores de Aloysia gratissima

Volatile oils from leaves and flowers of Aloysia gratissima were investigated for their chemical composition and antimicrobial activity against the bacteria Bacilus subtilis, Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa, Streptococcus pneumoniae and the Candida albicans yeast. The minimum inhibitory concentrations (MIC) of the oils were determined by the micro-dilution method, while the chemical composition was determined by GC-MS (gas chromatography mass spectrometry). The fresh leaves and inflorescence were subjected to hydrodistillation for 120 min using a Clevenger-type apparatus, and the essential oil was tested against microorganisms. High concentrations of sesquiterpenes were observed for the inflorescence, and monoterpenes were observed for the leaves. The main compounds of the inflorescence essential oil were E-caryophyllene, germacrene B, guaiol and bulnesol, while in the leaves the main compounds were trans-pinocamphone, trans-pinocarveyl acetate, and guaiol. The essential oil from the leaves showed an effect against P. aeruginosa and S. pneumonia, and the essential oil of the inflorescence showed an effect against P. aeruginosa, S. pneumonia, and Candida albicans.

O óleo essencial de folhas e de flores de Aloysia gratissima foi avaliado quanto à composição química e ação antimicrobiana contra as bactérias Bacilus subtilis, Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa, Streptococcus pneumoniae, e a levedura Candida albicans. A concentração mínima inibitória (MIC) dos óleos essenciais foi determinada pelo método da microdiluição e a composição química determinada por CG-EM (Cromatografia Gasosa acoplada a Espectrômetro de Massas). Folhas e inflorescências frescas foram hidrodestiladas por 120 minutos em aparelho Clevenger sendo o óleo essencial testado contra microorganismos. Para as flores foi observada maior concentração de sesquiterpenos, enquanto que as folhas apresentaram maior concentração de monoterpenos. Os principais constituintes do óleo essencial da flor foram: E-cariofileno, germacreno B, guaiol e bulnesol; e das folhas foram: trans-pinocamfona, acetato de trans-pinocarveol e guaiol. O óleo essencial da folha mostrou atividade contra P. aeruginosa e S. pneumoniae, e o óleo essencial da flor mostrou atividade contra P. aeruginosa, S. pneumoniae e Candida albicans.

Efeito do BAP no cultivo in vitro de Ocimum selloi Benth / Effect of BAP on in vitro culture of Ocimum selloi Benth

Visando promover a proliferação de brotações em segmentos apicais e nodais de Ocimum selloi em diferentes concentrações de BAP, plantas jovens de 60 dias serviram de doadoras de segmentos apicais e nodais. Os segmentos foram inoculados em meio MS preparado com a metade da concentração dos sais, e acrescido de 1,5% de sacarose e diferentes concentrações de BAP. O experimento foi conduzido no delineamento fatorial, 3 x 4, sendo 3 as posições dos segmentos de O. selloi (segmento apical, primeiro e segundo segmentos nodais) e 4 concentrações de BAP (0 - controle; 2; 4 e 6 mg L-1). Aos 30 dias, foram avaliados o número, comprimento e biomassa fresca e seca de brotos e raízes. Os primeiros e segundos segmentos apresentaram melhores resultados na indução de brotos de O. selloi, 7 e 8 brotos/explante, nas diferentes concentrações de BAP; porém, não houve formação de raízes na presença da citocinina. Nas condições testadas, recomenda-se o uso do primeiro e segundo segmento nodal suplementando o meio de cultivo com BAP para a proliferação in vitro de brotações de O. selloi.

The present study was undertaken to develop the proliferation of sprouts in apical and nodal segments of Ocimum selloi with different BAP levels. Young plants aged 60 days were used as donors of nodal and apical segments. The segments were inoculated in MS medium at half the concentration of salts supplemented with 1.5% of sucrose and different BAP levels. The experiment was in 3 x 4 factorial arrangement, 3 positions of O. selloi segments (apical segment; first and second nodal segment) and 3 BAP levels (0 - control; 2; 4 and 6 mg L-1). After 30 days, the number, the length, and the fresh and dry biomass of sprouts and roots were evaluated. The first and the second segments showed better results in inducing O. selloi sprouts, 7 and 8 sprouts/explant, at the different BAP levels, but there was not root formation in the presence of the cytokinin. Under the tested conditions, use of the first and the second nodal segments is recommended in addition to supplementing the culture medium with BAP for in vitro proliferation of O. selloi sprouts.

Adaptações fisiológicas e anatômicas de melissa officinalis L. (Lamiaceae) cultivadas sob malhas termorrefletoras em diferentes intensidades luminosas / Physiological and morphological adaptations of melissa officinalis L. (Lamiaceae) cultivated under thermo-reflector shading nets at different luminous intensities

Objetivou-se, com a realização da pesquisa, avaliar modificações fisiológicas e anatômicas em plantas de melissa, cultivadas sob malhas termorrefletoras (Aluminet®), em diferentes níveis de sombreamento, visando conhecer a plasticidade fenotípica em resposta de adaptação a diferentes quantidades de luz. Os tratamentos foram caracterizados por plantas submetidas a pleno sol e a 20 e 60 por cento de intensidade luminosa, e arranjados conforme o delineamento inteiramente casualizado (DIC). As quantificações de clorofila foram feitas em quatro repetições, as medições das epidermes e parênquimas foram repetidas 15 vezes e utilizou-se 10 repetições para as avaliações das características de cloroplastos e grãos de amido destes. Plantas submetidas a 20 por cento de intensidade luminosa apresentaram maior quantidade de clorofila a e, portanto, maior razão clorofila a/b. Comparativamente, as folhas de melissa a pleno sol e a 60 por cento de luz apresentaram células da epiderme adaxial mais espessas, mas as células da epiderme abaxial mostraram características encontradas em folhas de sombra, ou seja, mais finas. Quanto maior a intensidade luminosa, maior o número de cloroplastos, porém, a pleno sol mostraram-se mais finos e com menor área. Os grãos de amido de plantas cultivadas sob ambientes sombreados tiveram maior área e ocuparam maior parte nos cloroplastos de plantas a 60 por cento de intensidade luminosa. Assim, plantas de melissa, quando submetidas ao sombreamento, tiveram plasticidade fenotípica.

The aim of this study was to evaluate physiological and anatomical modifications in lemon balm plants, cultivated under thermo-reflector nets (Aluminet®) at different levels of shading, in order to understand the phenotypic plasticity in adaptation response to different light quantities. The treatments were characterized by plants subjected to full sun and 20 and 60 percent of luminous intensity, and arranged in completely randomized design (CRD). The quantifications of chlorophylls were done in four replicates, the measurements of epidermis and parenchymas were repeated 15 times and 10 replicates were used to evaluate characteristics of chloroplasts and their starch grains. Plants subjected to 20 percent of luminous intensity showed higher quantity of chlorophyll a and, therefore, higher chlorophyll a/b ratio. Lemon balm leaves under full sun and 60 percent of light showed thicker adaxial epidermis cells, but the abaxial epidermis cells showed characteristics found in shaded leaves, i.e., they were slender. The higher the light intensity, the larger the number of chloroplasts; however, under full sun, they were slender and had smaller area. The starch grains of leaves grown under shaded environments showed larger area and, at 60 percent of luminous intensity, occupied the largest part of chloroplasts. Thus, lemon balm plants, subjected to shading conditions, showed phenotypic plasticity.

Influência do processamento pós-colheita e armazenamento na composição química da droga vegetal e do óleo essencial de carqueja [Baccharis trimera (Less. ) DC. ] / Influence of post-harvest processing and storage on the chemical composition of drug and essential oil from "carqueja" [Baccharis trimera (Less. ) DC. ]

A carqueja-amarga [Baccharis trimera (Asteraceae)] é uma espécie originária do centro-sul da América do Sul. Análises qualitativas e quantitativas foram realizadas utilizando-se a técnica de CG-MS, para avaliar o efeito de diferentes formas de beneficiamento pós-colheita de drogas vegetais constituídas de partes aéreas de carqueja na composição química do óleo essencial, bem como verificar variações na composição quando conservado a -6ºC, durante 8 meses. O armazenamento da droga pulverizada reduziu significativamente o teor de óleo essencial, o que não aconteceu na droga fragmentada. Os teores dos constituintes majoritários espatulenol e ledol não foram influenciados pelo tratamento pós-colheita, embora tenham apresentado variações distintas redução nas concentrações de ledol e aumento nos teores de espatulenol. Verificou-se que as drogas fragmentadas podem ser armazenadas por até 12 meses e pulverizadas no momento da extração, não conferindo redução no teor de óleo essencial, nem dos constituintes químicos. O armazenamento a -6ºC por até oito meses, provocou variações quantitativas em alguns constituintes minoritários, tais como a-guaieno, b-selineno, germacreno B e espatulenol.

"Carqueja-amarga" [Baccharis trimera (Asteraceae)] is a species from the central south of South America. Qualitative and quantitative analyses were performed using the technique gas chromatography coupled to mass spectrometry to evaluate the effect of different post-harvest processing forms of drugs constituted of parts of "carqueja" on the chemical composition of its essential oil. The variation in the chemical composition of the essential oil stored at -6ºC for up to eight months was also evaluated. Storage of powdered drug significantly reduced the essential oil content, which was not observed for fragmented drug. The concentration of the major constituents of "carqueja" essential oil, spathulenol and ledol, was not affected by the post-harvest treatment, although they presented distinct variations, with ledol concentrations reducing and spathulenol concentrations increasing. We found that fragmented drugs can be stored for up to 12 months and powdered at the moment of extraction, without reducing the concentration of the essential oil or its chemical constituents. Storage at -6ºC for eight months caused quantitative variations in some minor constituents of the essential oil such as a-guaiene, b-selinene, germacrene B and espathulenol.

Acute carotid occlusion and stroke due to antiphospholipid antibody syndrome: case report and literature review.

Neurologic events associated to antiphospholipoid syndrome (APLS) are not uncommon, but ischemic stroke due to acute carotid thrombosis, is a rare presentation of this syndrome. We report a case of a 48 years old female patient, without evidence of atherothrombosis or other vascular pathology, who presented an ischemic stroke due to acute thrombosis of the left internal carotid artery. The occlusion was diagnosed by Duplex scan and magnetic resonance angiography (Ds+MRA). The patient was anticoagulated and experienced total regression of her neurologic symptoms after a week. Ds+MRA were performed again and confirmed re-establishment of normal flow of internal carotid artery. A thorough clinical investigation confirmed the diagnosis of APLS (the association of a major thombotic event and high anticardiolipoid IgG antibody titers in three blood samples). The patient has been submitted to oral anticoagulation for three years and has not experienced new neurologic or thrombotic events.

Adubação orgânica na produção de biomassa de plantas, teor e qualidade de óleo essencial de orégano (Origanum vulgare L. ) em cultivo protegido / Organic fertilization on phytomass production and essential oil content and quality of oregano (Origanum vulgare L. ) under protected cultivation

Origanum vulgare L., conhecida como orégano, é considerada planta condimentar largamente usada na culinária. No Brasil poucas são as pesquisas com esta espécie visando maximização das técnicas de cultivo. Objetivou-se avaliar os efeitos de diferentes doses dos adubos orgânicos bovino e aves no crescimento de plantas, teor de clorofila, teor, rendimento e qualidade do óleo essencial de orégano cultivado sob estufa. Foram conduzidos dois ensaios, sendo um com esterco bovino e o outro com esterco de aves (Poedeira). Plantas de orégano (Origanum vulgare L.) foram cultivadas em vasos de 10 L submetidas aos seguintes tratamentos: Ensaio I: Esterco bovino: 1) Solo sem adubação (controle); 2) solo + 3,0 kg m-2 de esterco bovino; 3) solo + 6,0 kg m-2 de esterco bovino; 4) solo + 9,0 kg m-2 de esterco bovino; 5) solo + 12,0 kg m-2 de esterco bovino; Ensaio II - Esterco de aves: 1) solo sem adubação (Controle); 2) solo + 1,5 kg m-2 de esterco de galinha; 3) solo + 3,0 kg m-2 de esterco de galinha; 4) solo + 4,5 kg m-2 de esterco de galinha e 5) solo + 6,0 kg m-2 de esterco de galinha. Ambos os ensaios foram conduzidos em delineamento blocos ao acaso com 4 repetições e a parcela experimental composta de 4 vasos. Foi observado que as doses de adubos bovino e avícola influenciaram significativamente no crescimento das plantas, rendimento e composição química do óleo essencial de orégano.

Origanum vulgare L., known as oregano or wild marjoram, is an aromatic plant widely used in cookery. In Brazil, there are few studies with this species aimed at improving the cultivation techniques. The present study was carried out to evaluate the effect of different levels of cattle and chicken organic manure on plant growth, chlorophyll content, besides essential oil content, yield and quality of oregano grown in a greenhouse. Two assays were carried out, one of them used cattle manure and the other, chicken manure (Hen). Oregano (Origanum vulgare L.) plants were grown in 10L-pots and subjected to the following treatments: Assay I: Cattle manure: 1) Soil without fertilization (control); 2) Soil + 3.0 kg m-2 cattle manure; 3) Soil + 6.0 kg m-2 cattle manure; 4) Soil + 9.0 kg m-2 cattle manure; and 5) Soil + 12.0 kg m-2 cattle manure; Assay II: Chicken manure: 1) Soil without fertilization (control); 2) Soil + 1.5 kg m-2 chicken manure; 3) Soil + 3.0 kg m-2 chicken manure; 4) Soil + 4.5 kg m-2 chicken manure; and 5) Soil + 6.0 kg m-2 chicken manure. The experimental design for both assays was in randomized blocks with four replicates and four pots per plot. Cattle and chicken manure levels significantly influenced oregano plant growth besides essential oil yield and chemical composition.

Produção de mudas de Aloysia gratissima (Gillies & Hook. ) Tronc. por meio da propagação sexuada e assexuada / Aloysia gratissima (Gillies & Hook. ) Tronc. seedling production through sexual and asexual propagation

A alfazema-do-Brasil é planta de importância medicinal, como produtora de terpenos. A principal descrição etnofarmaco-botânica aponta como sendo eficaz para infecções brônquicas, pulmonares e da bexiga. O objetivo do trabalho foi estudar a propagação de A. gratissima visando a obtenção de mudas. Na propagação sexuada estudou-se a influência da temperatura na presença e ausência de luz e três épocas de coleta das sementes (março, junho e setembro). Na propagação via semente foram testados três diferentes substratos (areia, palha de arroz carbonizada, Plantmax®). Na propagação vegetativa foram testados dois tipos de estacas (herbáceas e semi-lenhosas) e de dois substratos (areia e Plantmax®). Os resultados indicaram que na propagação sexuada, a germinação das sementes foi maior nas temperaturas constantes de 20 e 25°C, e a melhor época de coleta de sementes foi em março. O substrato comercial mostrou-se superior para o crescimento das plântulas, atingindo 93,25 por cento de emergência das sementes e 100 por cento de sobrevivência. Para a propagação assexuada, as estacas herbáceas em substrato comercial e areia apresentaram 96 e 95 por cento de enraizamento, respectivamente.

Brazilian-lavender is a medicinally important plant since it produces terpenes. As regards ethnopharmacology, it is mainly efficient against bronchial, lung and bladder infections. The aim of this work was to study Aloysia gratissima propagation for seedling production. In sexual propagation, temperature influence in the presence and absence of light and three seed harvesting times (March, June, and September) were studied. Three different substrates (sand, carbonized rice husk, Plantmax®) were also evaluated for seed germination. In vegetative propagation, two cutting types (herbaceous and semihardwood) and two substrates (sand, Plantmax®) were tested. Seed germination was higher under constant temperatures of 20 and 25ºC, and March was the best seed harvest time for sexual propagation. The commercial substrate was the best for seedling growth, peaking 93.25 percent seedling emergency and 100 percent survival. For asexual propagation, herbaceous cuttings in the commercial substrate and sand presented 96 percent and 95 percent rooting, respectively.

Teor e composição química do óleo essencial de Hyptis marrubioides Epling (Lamiaceae) em diferentes genótipos / Essential oil content and chemical composition in Hyptis marrubioides Epl. of different genotypes

Hyptis marrubioides Epling (hortelã-do-campo) é espécie de uso medicinal conhecida pelas suas atividades contra infecções gastrointestinais, infecções de pele, dores e câimbras. Objetivou-se com este trabalho, avaliar o teor e composição química do óleo essencial de H. marrubioides em diferentes genótipos (roxo e branco) e partes da planta fresca (folhas, inflorescências e caule). Os genótipos estudados foram identificados através das inflorescências das plantas que apresentam coloração roxa e branca. O delineamento experimental foi inteiramente casualizado, contendo as três partes da planta de ambos os genótipos, perfazendo um fatorial 3x2, com quatro repetições. O óleo essencial foi extraído por hidrodestilação por duas horas e analisado por Cromatografia Gasosa acoplada a Espectrometria de Massas (CG-EM). O maior teor de óleo essencial foi observado na inflorescência do genótipo roxo. A composição do óleo essencial de H. marrubioides variou quantitativamente entre as partes das plantas analisadas e entre os genótipos. O composto α-tujona apresentou a maior porcentagem de área do pico nas inflorescências de genótipo roxo. As porcentagens das plantas com genótipo roxo foram em média superiores às plantas com genótipo branco.

Hyptis marrubioides Epling ("hortelã-do-campo") is a medicinal species known for its activities against gastrointestinal and skin infections, pains and cramps. The aim of this work was to evaluate essential oil content and chemical composition in H. marrubioides of different genotypes (purple and white), as well as fresh plant parts (leaves, inflorescences and stem). The studied genotypes were identified based on the inflorescences, which are purple and white. The experimental design was completely randomized, including the three parts of both genotypes, in a 3X2 factorial arrangement, with four replicates. Essential oil was extracted through hydrodistillation for two hours and analyzed using Gas Chromatography attached to a Mass Spectrometry (GC-MS). The highest essential oil content was found for the inflorescence of purple genotype. Hyptis marrubioides essential oil composition quantitatively varied among the analyzed plant parts and between genotypes. The compound α-thujone had the highest percentage of apex area in inflorescences of purple genotype. The percentages of purple genotype were on average higher than those of white one.

Extracellular acidification related to the stimulation of catecholamines release by strontium in the bovine adrenal medulla.

The possible modifications of extracellular pH associated with the secretion of catecholamines evoked by the introduction of 2.2 mM Sr2+ to a Ca(2+)-free, buffer-free, Locke solution were investigated in decorticated perfused bovine adrenal glands. A progressive and reversible decrease of external pH accompanied the catecholamine release promoted by Sr(2+)-introduction into the perfusion fluid. This extracellular acid shift was practically undetected when the chromaffin tissue was stimulated by the addition of Sr2+ to a buffered medium. Both the secretory response as well as the extracellular pH drop mediated by Sr(2+)-introduction to a Ca(2+)-free, buffer-free, Locke solution were markedly inhibited by methoxyverapamil (0.3 mM), Mg2+ (20 mM) and hyperosmolarity (750 mOsm). The exposure of the adrenal medulla to a Ca(2+)-free, buffer-free, high-K+ solution containing 2.2 mM Sr2+ for 6 min promoted a significant enhancement of both the secretory response and the acidification of the perfusates compared with the responses evoked by Sr2+ in a 5.6 mM K+ medium. These results are consistent with the existence of a close relationship between extracellular acidification and the release of catecholamines triggered by the introduction of Sr2+ to the perfusion fluid.

Effect of hyperosmolarity on extracellular acidification associated with catecholamine secretion evoked by barium in perfused bovine adrenal medulla.

1. The effects of the increase of osmotic strength on extracellular pH modifications produced during buffer-free, 5 mM Ba2+ stimulation was studied in decorticated perfused bovine adrenal glands. 2. A pronounced and reversible attenuation of the extracellular pH drop as well as of the release of catecholamines induced by Ba2+ was detected in glands exposed to a hyperosmotic (750 mOsm) perfusion fluid made up by the addition of NaCl. 3. Similar results were observed using sucrose as osmoticant instead of NaCl. 4. A progressive decline in both external acidification and secretory response to Ba2+ was found on gradually increasing the osmotic strength of the perfusion fluid. 5. These results provide additional evidence in favour of the existence of a close association between extracellular acidification and adrenomedullary secretion induced by buffer-free Ba2+.

Characterization of extracellular pH drop due to the activation of the secretory process by acetylcholine in the bovine adrenal medulla.

A progressive and reversible decrease of external pH accompanied the catecholamine release elicited by acetylcholine in decorticated bovine adrenal glands perfused with buffer-free Locke solution adjusted to an initial pH of 7.4. Both the secretory response as well as the extracellular acid shift promoted by the cholinergic agonist were antagonized by hexamethonium plus atropine, Mg2+ and verapamil. Experiments performed to assess the effects of the reduction of external pH on acetylcholine-induced release of catecholamines revealed that increasing the extracellular concentration of H+ significantly and reversibly reduced this secretory response. These findings are consistent with the idea that adrenomedullary activation of secretion by acetylcholine could be associated with a transient acidification of the extracellular fluid. This release of protons, arising mainly from the chromaffin granules, may be involved in a local automodulatory mechanism of the regulated secretory process.

In vitro evaluation of acute effects of mitoxantrone (Novantrone) in rat and guinea pig atria.

Since guinea pig and rat atria have been used as models to study acute anthracycline-induced cardiotoxicity, experiments were carried out in these preparations to evaluate possible acute cardiac effects mediated by mitoxantrone (MTX). After a latency period of approximately 90 min, MTX (10(-5)-10(-4) M) promoted a concentration-related and time-dependent decrease of spontaneous rate in guinea pig atria. A similar but less intense effect after a longer latency interval was observed in rat atria. In this preparation, MTX (10(-5)-10(-4) M) incubated up to 150 min., induced a gradual competitive beta-adrenergic blocking effect on the positive chronotropic action of isoproterenol. This was characterized by a progressive decline of pD2 values without altering Emax. A similar and stronger effect was found in isolated guinea pig atria incubated under same conditions with MTX, except that 10(-4) M exposed for 150 min. was able to depress the Emax to isoproterenol by 21.2%. In addition, MTX (10(-4) M) in this model promoted a non-competitive antagonistic effect on the chronotropic action of histamine. These data are compatible with the idea that MTX could induce cardiac acute effects qualitatively similar to but of lower potency than those produced by doxorubicin in these two models. In addition, guinea pig atria seemed to display higher sensitivity to MTX compared to rat atrial preparations.

Decrease of extracellular pH associated with the secretion of catecholamines induced by barium in perfused bovine adrenal medulla.

1. The possible modifications of extracellular pH produced during buffer-free 5 mM Ba2+ stimulation was studied in decorticated perfused bovine adrenal glands. 2. A significant and reversible drop of pH accompanied the release of catecholamines each time the tissue was exposed to a buffer-free 5 mM Ba2+ solution. 3. A progressive declination of the magnitude of this acidification associated with a gradual attenuation of the secretory response was observed consecutive to successive periods of Ba(2+)-stimulation. 4. D-600 (methoxyverapamil), in a concentration of 3 x 10(-4) M, markedly antagonized both Ba(2+)-induced secretory response and extracellular pH drop. 5. Perfusion of adrenal medulla for 4 min period with Locke solution buffered at pH 6.9, significantly and reversibly reduced the secretory response to 5 mM Ba2+ (pH 6.9) compared to a first control response obtained 35 min before at pH 7.4. 6. These results are compatible with the view that Ba(2+)-induced secretory activity is accompanied by the release of protons which could be involved in a local negative automodulatory mechanism of adrenomedullary secretion.

Comparison of acute effects of mitoxantrone and doxorubicin in guinea-pig atria.

1. The acute effects of doxorubicin (DOX) and mitoxantrone (MTX) on basal rate and on positive chronotropic activity induced by 1-noradrenaline (1-NA) were investigated in isolated guinea-pig atria. 2. DOX (10(-5)-10(-4)M) progressively depressed atrial rate after a short latency period. Only 10(-4) M MTX reduced the spontaneous frequency after 120 and 180 min incubation. This effect was significantly lower to that elicited by DOX (10(-4)M). 3. Atropine (1.5 x 10(-6) M) and reserpine pretreatment did not affect the negative chronotropic action induced by DOX or MTX. 4. DOX (10(-5)-10(-4) M) produced a significant reduction of the maximal chronotropic response (Emax) to 1-noradrenaline (1-NA) after 60, 120 and 180 min of exposure. 5. MTX (10(-5)-10(-4) M) after 60 and 120 min incubation induced a beta-adrenergic, concentration- and time-dependent, competitive blocking effect. After 180 min of exposure, MTX (10(-4) M) reduced the Emax to 1-NA which was of less magnitude to that produced by DOX (10(-4) M). 6. Although both DOX and MTX depressed spontaneous and 1-NA induced chronotropic activity, MTX effects were of a slower onset and development compared to those exerted by DOX.

[The mitral valve apparatus: an anatomo-echocardiographic approach]. / Aparelho valvar mitral: um enfoque anátomo-ecocardiográfico.

The shape of the mitral valve ring, the position of its chordae and of its leaflets were studied in 34 normal hearts fixed through intra-ventricular injection of tamponate formalin. As the authors have assumed that the post-rigor left ventricle has an architecture very similar to that seen at to the end of ventricular systole, comparisons were made between the anatomical and the echocardiographic features usually seen at the end of the phase of the cardiac cycle. The mitral ring has the shape of a hyperbolic paraboloid, and this peculiar geometry explains why the "apical-four chambers" view, which explores the most superficial ring segments, is the more appropriate view for detecting mitral valve prolapses. In that incidence the valvar diameter is longer (2.43 +/- 0.45 cm) that in the "parasternal view" (1.99 +/- 0.45 cm) and the angle made by the leaflets is comparatively less acute ("four chambers" = 127.41 +/- 16.45 degrees; "parasternal" = 102.05 +/- 0.17 degrees). In the "four chamber" view the point of coaptation (which represents the vertex of the referred angle) is 0.45 +/- 0.17 cm far from the echographic line usually taken as the valvar plane (EVPL-echocardiographic valvar plane line) whereas in the other view, it is more distant from this line (0.59 +/- 0.16 cm). These two last factors make both leaflets closer to the left atrium and explains why mitral valve prolapse, when present, is more easily seen in that incidence.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of doxorubicin on the release of catecholamines from the bovine adrenal medulla.

We have studied the effects of the anthracycline doxorubicin on the release of catecholamines from the perfused bovine adrenal gland. Doxorubicin produced different concentration-dependent effects on adrenomedullary catecholamine secretion. At a 3 x 10(-6) M concentration, doxorubicin facilitated the secretory response induced by acetylcholine and 56 mM K+ but did not affect the spontaneous catecholamine output or that evoked by NaCl deprivation. Conversely, a higher concentration of doxorubicin (10(-4) M) resulted in a significant and irreversible inhibition of the spontaneous secretion of catecholamines, as well as of that caused by acetylcholine or high K+. Doxorubicin at this high concentration did not modify the catecholamine release induced by NaCl deprivation. These results suggest that doxorubicin effects could be mediated at the plasma membrane of the chromaffin cells. The present study is compatible with the idea that increased adrenomedullary catecholamine release is involved in the cardiotoxic action of relatively low doses of doxorubicin.

Cardiotoxicidad de la adriamicina: estudio farmacológico e histopatológico en ratas / Cardiotoxicity of adriamycin: pharmacological and histopathological study in rats

Trabajos recientes mostraron una disminución en la respuesta adrenérgica miocárdica en la insuficiencia cardíaca. Por ello evaluamos los efectos de un tratamiento subagudo con ADM sobre la actividad cardíaca de noradrenalina (NA) e ISOproterenol (ISO). Ratas Wistar de ambos sexos (300-400 g) recibieron ADM 4 mg/kg i.v. en los días 1 y 8. Los controles fueron inyectados con solución fisiológica. El día 21 se sacrificaron los animales y se estudió la histopatología cardíaca. Mediante curvas concentración-respuesta, se evaluó la actividad cronotrópica (CRONO) de NA en la aurícula dreecha aislada (Krebs-carbogeno, 37 grados centígrados). El efecto inotrópico (INO) de NA e ISO fue estudiado en aurícula izquierda, estimulada a 3 Hz. Cada grupo experimental incluyó 4-6 ratas. Las curvas concentración-respuesta a NA revelaron: 1) Desplazamiento a la derecha para CRONO en el grupo ADM (ED 50:7,1 + ou - 1,7. 10-7M versus 3,0 + ou - 1,4.10-8 M en controles; p<0,01).2) Un fenómeno similar para INO (ED 50:2,8 + ou - 0,2.10-7 M con ADM versus 2,3 + ou - 0,7.10-8 en controles; p<0,01). Con ISO, se obtuvieron resutados similares en INO (ED 50:1,8 + ou - 0,7.10-8 M con ADM, versus 3,6 + ou - 1,7.10-10 M en controles; p<0,001). Las ratas tratadas con ADM presentaron ascitis, derrame pleural y lesiones miocárdicas (miocitolisis, vacuolización, infiltración linfocitaria), no así las ratas control. El tratamiento subagudo con ADM deprime la respuesta beta-adrenérgica miocárdica en ratas. Este fenómeno se acompaña de signos histopatológicos de daño cardíaco. El presente modelo puede ser útil para evaluar posibles agentes protectores de la cardiotoxicidad promovida por la ADM