Leptodactylus vastos (LEPTODACTYLIDAE) PREDATION ON AN ENDEMIC FROG, AND A COMPILATION OF ITS DIET / Depredación de Leptodactylus vastus (Leptodactylidae) en una rana endémica y una recopilación de su dieta

RESUMEN La composición de la dieta constituye información básica sobre la historia natural de la especie. A pesar de la cantidad de datos adquiridos en los últimos años, aún queda mucho por conocer, especialmente para especies geográficamente extendidas. Aquí compilamos los elementos dietéticos disponibles de Leptodactylus vastus y reportamos el primer evento de depredación de Rupirana cardosoi por un juvenil de L. vastus. El hecho de que estas especies sean sintópicas en la región probablemente resultó en este nuevo evento de depredación. A diferencia de las observaciones previas de depredación de L. vastus, los especímenes que observamos no presentan una diferencia notable en el tamaño corporal, pero L. vastus fue capaz de casi tragar R. cardosoi, en coherencia con los hallazgos de que el tamaño de la boca está relacionado con la selección de presas en los anuros. Además, nuestra revisión de la literatura mostró que L. vastus es un depredador generalista y oportunista, que se alimenta de pequeños vertebrados (Amphibia, Squamata y Mammalia).

ABSTRACT Diet composition constitutes basic information on the natural history of the species. Despite the amount of data acquired in the last years, much remains to be known specially for geographically widespread species. Here we compiled the available dietary items of Leptodactylus vastus and report the first predation event upon Rupirana cardosoi by a juvenile L. vastus. The fact these species are syntopic in the region probably resulted in this novel predation event. Different from previous L. vastus predation observations, the specimens we observed do not present a striking difference in body size, but L. vastus was able to almost swallow L. cardosoi, coherent with findings that mouth size is related to prey selection in anurans. Also, our literature review showed that L. vastus is a generalist and opportunistic predator, that prey upon small vertebrates (Amphibia, Squamata, and Mammalia).

Quantity - but not diversity - of secreted peptides and proteins increases with age in the tree frog Pithecopus nordestinus

Amphibians inhabit the terrestrial environment, a conquest achieved after several evolutionary steps, which were still insufficient to make them completely independent of the aquatic environment. These processes gave rise to many morphological and physiological changes, making their skin (and cutaneous secretion) rich in bioactive molecules. Among the tree frogs, the secretion is composed mainly of peptides; but alkaloids, proteins and steroids can also be found depending on the species. The most known class of biologically active molecules is the antimicrobial peptides (AMPs) that act against bacteria, fungi and protozoans. Although these molecules are well-studied among the hylids, AMPs ontogeny remains unknown. Therefore, we performed peptidomic and proteomic analyses of Pithecopus nordestinus (formerly Phyllomedusa nordestina) in order to evaluate the peptide content in post-metamorphosed juveniles and adult individuals. Methods: Cutaneous secretion of both life stages of individuals was obtained and analyzed by LC-MS/MS after reduction and alkylation of disulfide bonds or reduction, alkylation and hydrolysis by trypsin. Results: Differences in the TIC profile of juveniles and adults in both treatments were observed. Moreover, the proteomic data revealed known proteins and peptides, with slight differences in the composition, according to the life stage and the treatment. AMPs were identified, and bradykinin-potentiating peptides were observed in trypsin-treated samples, which suggests a protein source of such peptide (cryptide). Conclusion: In general, skin secretion contents were similar between juveniles and adults, varying in quantity, indicating that the different stages of life are reflected in the number of molecules and not on their diversity.(AU)

Influence and mechanism of Xindakang on cardiac functions of isolated frog heart / 中国药理学与毒理学杂志

OBJECTIVE To evaluate the effects of flavonoids from Xindakang (Hippophae Fructus flavone) on myo?cardial systolic and diastolic functions of isolated frog hearts and explore the possible mechanism, and provide experi?mental basis for improving the effect and efficacy of Xindakang on cardiac function. METHODS The isolated frog heart perfusion specimens were prepared by Yagi's method, and the effects of different concentrations of Xindakang on myo?cardial contractility (0.0125, 0.025, 0.05, 0.1 and 0.2 g·L-1), heart rate and cardiac output of isolated frog heart were stud?ied. Acetylcholine, atropine and epinephrine were administered successively to analyze the effects of Xindakang on car?diac systolic function of isolated frogs under the action of different drugs, and compared with propranolol. The effect of extracellular calcium ion concentration on the action of Xindakang was studied by using low calcium concentration, high cal?cium concentration and normal Ren's solution. To study the effect and possible mechanism of Xindakang on cardiac systolic function of frog. RESULTS The concentration of Xindakang in the range of 0.0125-0.1 g·L-1 could weaken the contractility of isolated frog heart and increase the concentration of Xindakang. The inhibitory effect of Xindakang on con?tractility of isolated frog heart was enhanced, and showed obvious dose-effect relationship. Cardiac output was signifi?cantly decreased by Xindakang (P<0.01), slow heart rate (P<0.05); M receptor blocker atropine could not antagonize the contractile effect of Xindakang, and Xindakang could not completely antagonize the contractile effect of adrenalin. Xindakang could inhibit the isolated frog heart in low calcium concentration, high calcium concentration and normal Ren's solution, and increased with the increase of extracellular calcium concentration (P<0.01). CONCLUSION Xinda?kang has inhibitory effect on isolated frog heart, which may be achieved by blocking the calcium channel on myocardial cell membrane and reducing the calcium concentration in myocardial cells.

Leyendo a Spallanzani hoy en día / Reading Spallanzani today

Resumen Recordamos al abate Lázaro Spallanzani (1729-1799) fundamentalmente por su victoriosa contienda con Needham sobre la generación espontánea, pero fue un hombre de múltiples intereses en distintos campos de la ciencia, desde la biología a la volcanología. Se lo llamó el "biólogo de los biólogos", desarrollando una serie de investigaciones sobre la reproducción de los anfibios, en una de las cuales - "Experiencias al servicio de la historia de la generación de animales y plantas" - el lector moderno se estremece de horror ante las crueles mutilaciones que infligiera a los sapos machos tratando de interrumpir su copulación con las hembras. Él mismo las califica de "bárbaras" estas torturas, inadmisibles en un hombre que detentaba una jerarquía eclesiástica, aún en una época como la suya, en que se calificaba a los animales como "anima vili" (cosa sin valor). Mucho se ha avanzado hoy en día en resguardo de nuestros "hermanos menores", como los llamara San Francisco, pero aún falta mucho que hacer en la regulación de la experimentación científica que los utiliza.

Abstract We remember Lazaro Spallanzani (1729-1799) mainly for his controversy with Needham over spontaneous generation, but he was a man of multiple scientific activities in the fields of biology, mineralogy, physics, mathematics and… volcanology! Called "the biologist of biologists", he developed a series of investigations about reproduction of amphibian, in one of them -Experiences in service to the history of the generation of animals and plants- we have found horrific experiments with frogs, including severe and useless mutilation of males, in order to interrupt its copulation with females, acts he describes as "barbaric", and we estimate inadmissible in the ecclesiastic man he was, even in an epoch in which animals were considered "anima vili" (something without value). A brief review of the use of animals in laboratories shows significant advances in the ethical regulations for this practice, but we believe that these achievements are not enough.

Biochemical characterization and cytotoxic effect of the skin secretion from the red-spotted Argentina frog Argenteohyla siemersi (Anura: Hylidae)

Argenteohyla siemersi (red-spotted Argentina frog) is a casque-headed tree frog species belonging to the Hylidae family. This species has a complex combination of anti-predator defense mechanisms that include a highly lethal skin secretion. However, biochemical composition and biological effects of this secretion have not yet been studied. Methods: The A. siemersi skin secretion samples were analyzed by mass spectrometry and chromatographic analysis (MALDI-TOF/MS, RP-HPLC and GC-MS). Proteins were also studied by SDS-PAGE. Among the biological activities evaluated, several enzymatic activities (hemolytic, phospholipase A2, clotting, proteolytic and amidolytic) were assessed. Furthermore, the cytotoxic activity (cytolysis and fluorescence staining) was evaluated on myoblasts of the C2C12 cell line. Results: The MALDI-TOF/MS analysis identified polypeptides and proteins in the aqueous solution of A. siemersi skin secretion. SDS-PAGE revealed the presence of proteins with molecular masses from 15 to 55 kDa. Steroids, but no alkaloids or peptides (less than 5 KDa), were detected using mass spectrometry. Skin secretion revealed the presence of lipids in methanolic extract, as analyzed by CG-MS. This secretion showed hemolytic and phospholipase A2 activities, but was devoid of amidolytic, proteolytic or clotting activities. Moreover, dose-dependent cytotoxicity in cultured C2C12 myoblasts of the skin secretion was demonstrated. Morphological analysis, quantification of lactate dehydrogenase release and fluorescence staining indicated that the cell death triggered by this secretion involved necrosis. Conclusions: Results presented herein evidence the biochemical composition and biological effects of A. siemersi skin secretion and contribute to the knowledge on the defense mechanisms of casque-headed frogs.(AU)

A review on the conservation genetic studies of Indian amphibians and their implications on developing strategies for conservation

Amphibians show a very high level of diversity and endemism and are facing global declines from the past few decades. Studies have shown that the molecular tools can be helpful in their conservation efforts. In India, more than 80% of amphibians are endemic and most show a narrow range of distribution. Most of the Indian amphibians lack information on their genetic diversity. In this study, were view the overall trend on amphibian studies in India with the specific focus on conservation genetics. Overall, of the 173 studies, only 14 dealt with the conservation of amphibians through genetic tools and five studies estimated the genetic diversity or gene structure. Here, we discuss the gaps and provide future directions on how genetic studies can be helpful in Indian amphibian conservation.

Revisión taxonómica de la rana marsupial Gastrotheca peruana (Amphibia: Hemiphractidae) en base al gen mitocondrial 16S / Taxonomic evaluation of the marsupial frog Gastrotheca peruana (Amphibia: Hemiphractidae) based on mitochondrial 16S rRNA gene

Se revisa el estado taxonómico de Gastrotheca peruana usando métodos filogenéticos en base a secuencias de 16S rRNA. Los árboles de máxima verosimilitud y Bayesiano mostraron que las variantes génicas de G. peruana forman dos clados que no son hermanos. Uno de estos clados se distribuye en el norte de Perú, incluyendo un individuo procedente de la localidad típica de G. peruana dissimilis. El segundo clado está restringido al centro de Perú y contiene individuos de las localidades tipo de dos formas nominales, G. p. peruana y G. p. junensis, y es hermano de G. aratia. De esta forma, reconocemos dos especies dentro de lo que actualmente se conoce como G. peruana. Restringimos Gastrotheca peruana a las poblaciones del centro de Perú (departamentos de Ancash, Lima, Pasco y Junín) y asignamos Gastrotheca dissimilis a las poblaciones de los departamentos de La Libertad y Cajamarca.

The taxonomic status of Gastrotheca peruana is evaluated using phylogenetic methods and 16S gene sequences. The maximum likelihood and Bayesian trees showed that the genetic variants of G. peruana form two clades that are not sister to each other. One of these clades is present in northern Perú and includes a specimen collected at the type locality of G. peruana dissimilis. The other clade is restricted to central Peru and contains individuals from type localities of two nominal forms, G. p. peruana and G. p. junensis, and is sister to G. aratia. Our results suggest that G. peruana sensu lato currently encompass two species. We restrict Gastrotheca peruana to populations from central Perú (departments of Ancash, Lima, Pasco and Junín) and assign populations from departments of La Libertad and Cajamarca to Gastrotheca dissimilis.

Evaluación de la abundancia relativa de Telmatobius culeus en la zona litoral del lago Titicaca, Perú / Assessment of relative abundance of Telmatobius culeus in littoral zone of Lake Titicaca, Peru

El estudio se realizó en 13 zonas del litoral peruano del lago Titicaca, durante la época seca, desde junio hasta agosto de 2017. En cada zona se determinó la abundancia relativa y uso de microhábitat de Telmatobius culeus. En las zonas de evaluación se utilizó buceo con esnórquel para realizar en cada una tres transectos de 100 m x 2 m, con un total de 38 transectos evaluados. Se registraron 45 individuos en solo seis zonas de evaluación. El mayor número de individuos se encontraron en la zona de Perka Norte, con una abundancia relativa de 10.33 individuos/hora/02 personas a una profundidad de 1.5 m; en siete zonas no se registró ningún individuo. Los individuos fueron encontrados en los siguientes micro hábitats: 17 fueron encontrados sobre la vegetación acuática, 11 en arena combinado con vegetación acuática, 9 en roca combinado con vegetación acuática, 5 en fango combinado con vegetación acuática, 2 en roca y 1 en arena. a la vez se realizó análisis de diferentes parámetros de calidad de agua en cada zona de estudio, como: temperatura, pH, alcalinidad, dureza y oxígeno.

The Telmatobius culeus relative abundance and its microhabitat use was determined. In 13 areas of Peruvian littoral of Lake Titicaca was carried out, during the dry season, since June to August 2017. In each the evaluation areas, snorkeling was used to perform three 100 x 2 m transects. A total of 38 transects were evaluated. 45 individuals were registered in only six evaluation zones. The largest number of individuals were found in the North Perka area, with a relative abundance of 10.33 individuals/hour/02 people, at a depth of 1.5 m; in seven zones no individual was registered. Individuals were found in the following micro habitats: 17 were found on aquatic vegetation, 11 in sand combined with aquatic vegetation, 9 in rock combined with aquatic vegetation, 5 in mud combined with aquatic vegetation, 2 in rock and 1 in sand. At the same time, analyzes of different water quality parameters were performed in each study area, such as: temperature, pH, alkalinity, hardness and oxygen.

WATER-BUG (Abedus SP.; BELOSTOMATIDAE) PREDATION ON THE CRITICALLY ENDANGERED Atelopus varius (BUFONIDAE) AT LAS TABLAS PROTECTED ZONE, COSTA RICA / Depredación por el Chinche de Agua (Abedus sp.; Belostomatidae) sobre el Críticamente Amenazado Atelopus varius (Bufonidae) en la Zona Protectora Las Tablas, Costa Rica

ABSTRACT Atelopus varius was believed to be extinct in Costa Rica until the rediscovery of a population within the Las Tablas Protected Zone (LTPZ) in 2008. This rediscovery represented a research and conservation opportunity, including contributing new information about the species' natural history. There are few reported species that prey on A. varius. This report presents a new predation record by a species of water bug (Abedus spp.) on an adult harlequin frog (A. varius). This is only the second confirmed predator for the species. These water bugs have been reported to prey on anurans during reproductive seasons, but in this case, the event occurred on A. varius out of their reproductive season. The effects of water bug predation on the only known reproductive population of this Critically Endangered species needs to be assessed to consider appropriate conservation measures to prevent further decline of the species.

RESUMEN Atelopus varius se consideró extinto en Costa Rica, hasta el redescubrimiento de una población en la Zona Protectora Las Tablas (ZPLT). Este hallazgo representa una oportunidad de investigación y conservación, incluyendo contribuir nueva información acerca de la historia natural de la especie. Hay pocas especies reportadas que depredan A. varius. Este reporte presenta un registro de depredación del chinche de agua (Abedus spp.), sobre un adulto de Sapo Arlequín (A. varius), como el segundo depredador confirmado de la especie. Usualmente, los chinches de agua depredan anuros durante su época reproductiva, pero este evento ocurrió fuera de la época reproductiva de A. varius. Los efectos de la depredación de chinches acuáticos sobre la única población reproductiva conocida de esta especie Críticamente Amenazada necesitan ser evaluados para considerar acciones de conservación.

The prediction of baicalin content in the extraction process of Scutellaria baicalensis by near-infrared spectroscopy combined with different variable selection methods / 药学学报

Near-infrared spectroscopy (NIRS) combined with chemometrics can achieve rapid detection in process analysis. After variable selection, the redundant information is effectively removed and the characteristic variables related to the response values are selected. Compared with global model, the complexity is significantly reduced and the prediction accuracy is also improved. In this study, near-infrared spectroscopy analysis combined with different variable selection methods was applied to achieve the rapid detection of baicalin in the extraction process of Scutellaria baicalensis. Data sets were divided based on sample set portioning based on joint x-y distance (SPXY) method. Competitive adaptive weighted resampling method (CARS), random frog (RF) and successive projections algorithm (SPA) were applied to variable selection. Partial least squares (PLS) models were constructed based on above three methods, and the prediction results were compared. After CARS, RF and SPA method, 92, 10 and 17 variables were screened out respectively. According to the performance of the models, CARS method is found to be more effective and suitable than RF and SPA. Furthermore, the characteristic variables selected by CARS method have a better correspondence with the chemical structure of baicalin. The root mean square error (RMSEC) of the calibration set and the root mean square error (RMSEP) of the prediction set are 0.528 2 and 0.720 2 respectively. Compared with the global PLS model, the correlation coefficient of the calibration set (Rc) is increased to 0.979 9 from 0.917 0, and the relative standard errors of prediction (RSEP) is reduced to 5.59% from 10.58%.

Hypolipidemic activity of low-cholesterol ovum oil of Rana chensinensis and phytosterol (stigmasterol) in rats / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The ovum oil of forest frog has various health beneficial functions. In the current research, we evaluated the hypolipidemic effects of the low-cholesterol ovum oil from the forest frog and its combination with stigmasterol in rats.

Effects of Ethyl Acetate Part from Ethanol Extract of Miao Medicine Periploca forrestii on Cardiac Function of Isolated Frog Heart / 中国药房

OBJECTIVE： To study the effects of ethyl acetate part form the ethanol extract of Periploca forrestii on cardiac function of isolated frog heart， and to primarily investigate its potential mechanism. METHODS： The isolated frog heart samples were prepared by using the intube method of steinmann. The Ren’s solution （blank control）， 1.70 mg/mL and 3.48 mg/mL ethyl acetate part from ethanol extract of P. forrestii were used to perfuse the sample. The BL-420 biological function experimental system was used to record the changes in heart rate and myocardial contractility. The effects of ethyl acetate part from ethanol extract of P. forrestii on cardiac function of isolated frog heart were investigated. After perfused with 10 mg/L atropine， 20 μL isoproterenol， 1 μL low calcium （per 1 000 mL pure water contain 0.06 g CaCl2）， high calcium Ren’s solution （per 1 000 mL pure water contain 0.24 g CaCl2）， adding 1.74 mg/mL ethyl acetate part from ethanol extract of P. forrestii， the changes of myocardial contractility in isolated hearts were recorded by BL-420 biological function experimental system. Myocardial tissue was collected after perfused with Ren’s solution （blank control） and ethyl acetate part from ethanol extract of P. forrestii with 1.74 and 3.48   mg/mL. The activity of Na+-K+-ATPase， Ca2+-Mg2+-ATPase and AChE were detected to investigate the potential mechanism of the effects of ethyl acetate extract from ethanol extract of P. forrestii on cardiac function. RESULTS： Compared with blank control， mean myocardial contractility was significantly decreased （P＜0.001） after adding 1.74， 3.48 mg/mL ethyl acetate part form ethanol extract of P. forrestii， but had no significant on heart rate （P＞0.05）. With the increase of extracellular Ca2+ concentration， the inhibitory effect of ethyl acetate part from ethanol extract of P. forrestii on isolated frog heart contraction also increased gradually. After adding atropine and isoproterenol， the inhibitory effect of the ethyl acetate part form ethanol extract of P. forrestii on isolated frog heart contraction decreased to some certain. The activity of Na+-K+-ATPase in cardiac tissue was not significantly changed （P＞0.05）， the activity of Ca2+-Mg2+-ATPase was significantly increased （P＜0.05）， and the activity of AChE was significantly decreased （P＜0.05） after perfused with 1.74， 3.48 mg/mL ethyl acetate part form ethanol extract of P. forrestii. CONCLUSIONS： The ethyl acetate part from the ethanol extract of P. forrestii can inhibit the contractile activity of the isolated frog heart and has a certain negative inotropic effect. The mechanism may be related to the increase of Ca2+-Mg2+-ATPase activity， inhibition of AChE activity， blocking of calcium channel in the cell membrane， the activation of M receptor and blocking of β receptor.

Role of bone status in anterolateral portion of femoral head in the progression of osteonecrosis of the femoral head / 中国组织工程研究

BACKGROUND:Mechanical stress plays an important role in the progressive collapse in osteonecrosis of the femoral head.Therefore,the bone structure of weight-bearing area may be the risk factor for collapse.OBJECTIVE:To investigate the relationship between the bone preservation of weight-bearing area and collapse progression in necrotic femoral head.METHODS:Eighty-seven patients (102 hips) with ARCO stage Ⅱ osteonecrosis of the femoral head,diagnosed by MRI,were enrolled.All patients underwent a natural progression.Collapse and bone involvement of the weight-bearing area were viewed by anteroposterior and frog-leg lateral radiographs.According to the location of the necrotic lesion on the anterolateral portion of the femoral head,the necrosis was divided into three types:type 1,the posteromedial and central portions;type 2,part of the anterolateral portion;type 3,the entire anterolateral portion.The collapse rate and the time to collapse in different types were assessed.RESULTS AND CONCLUSION:(1) All patients were followed up for 3-58 months.(2) Of the 60 hips with collapse,46 (76.7％) hip collapse was identified on anteroposterior radiograph.On frog-leg lateral radiograph showing collapsed femoral head could be identified in 57 (95.0％) hips,which was significantly different (P ＜ 0.01).(3) In all 102 hips,the collapse rate in type 3 osteonecrosis of the femoral head was significantly higher than that of type 2 osteonecrosis of the femoral head (P ＜ 0.001),and the time to collapse was markedly shortened.None collapse occurred in all six hips with type Ⅰ osteonecrosis of the femoral head during follow-up.(4) In summary,preservation of anterolateral portion is associated with potential collapse progression in necrotic femoral head.

Ocorrência de Amblyomma rotundatum Koch, 1844 (Acari: Ixodidae) em Rhinella icterica (Spix, 1824) (Anura: Bufonidae) em Maricá, Rio de Janeiro, Brasil / Occurrence of Amblyomma rotundatum Koch, 1844 (Acari: Ixodidae) in Rhinella icterica (Spix, 1824) (Anura: Bufonidae) in Maricá, Rio de Janeiro, Brazil / Ocurrencia de Amblyomma rotundatum Koch, 1844 (Acari: Ixodidae) en Rhinella icterica (Spix, 1824) (Anura: Bufonidae) en Maricá, Río de Janeiro, Brasil

Anfíbios anuros são comumente parasitados por carrapatos da espécie Amblyomma rotundatum, os quais possuem alta predileção por animais ectotérmicos. Fêmeas e ninfas ingurgitadas de A. rotundatum foram coletadas em condições naturais a partir de um espécime de "sapo-cururu" da espécie Rhinella icterica. A identificação dos carrapatos foi feita por meio de características morfológicas. Este é o primeiro relato do parasitismo deste carrapato em sapos desta espécie no Município de Maricá, Região Metropolitana do Estado do Rio de Janeiro, Brasil.(AU)

Anuran amphibians are commonly parasitized by ticks of the species Amblyomma rotundatum, which have high predilection for ectothermic animals. Engorged females and nymphs of A. rotundatum were collected under natural conditions from a "toad-cururu" specimen of the species Rhinella icterica. The identification of ticks was made through morphological characteristics. This is the first report of the parasitism of this tick in toads of this species in the Municipality of Maricá, Metropolitan Region of the State of Rio de Janeiro, Brazil.(AU)

Los anfibios anuros son comúnmente parasitados por garrapatas de la especie Amblyomma rotundatum, los cuales poseen alta predilección por animales ectotermos. Las hembras y ninfas ingurgitadas de A. rotundatum fueron recolectadas en condiciones naturales a partir de un espécimen de "sapo cururú" de la especie Rhinella icterica. La identificación de las garrapatas se ha hecho a través de características morfológicas. Este es el primer relato del parasitismo de esta garrapata en sapos de esta especie en el Municipio de Maricá, Región Metropolitana del Estado de Río de Janeiro, Brasil.(AU)

Effect of Sciatic Nerve Transection on acetylcholinesterase activity in spinal cord and skeletal muscles of the bullfrog Lithobates catesbeianus / Efeito da Secção do Nervo Isquiático sobre a atividade da acetilcolinesterase em medula espinal e músculos esqueléticos da rã-touro Lithobates catesbeianus

Abstract Sciatic nerve transection (SNT), a model for studying neuropathic pain, mimics the clinical symptoms of "phantom limb", a pain condition that arises in humans after amputation or transverse spinal lesions. In some vertebrate tissues, this condition decreases acetylcholinesterase (AChE) activity, the enzyme responsible for fast hydrolysis of released acetylcholine in cholinergic synapses. In spinal cord of frog Rana pipiens, this enzyme's activity was not significantly changed in the first days following ventral root transection, another model for studying neuropathic pain. An answerable question is whether SNT decreases AChE activity in spinal cord of frog Lithobates catesbeianus, a species that has been used as a model for studying SNT-induced neuropathic pain. Since each animal model has been created with a specific methodology, and the findings tend to vary widely with slight changes in the method used to induce pain, our study assessed AChE activity 3 and 10 days after complete SNT in lumbosacral spinal cord of adult male bullfrog Lithobates catesbeianus. Because there are time scale differences of motor endplate maturation in rat skeletal muscles, our study also measured the AChE activity in bullfrog tibial posticus (a postural muscle) and gastrocnemius (a typical skeletal muscle that is frequently used to study the motor system) muscles. AChE activity did not show significant changes 3 and 10 days following SNT in spinal cord. Also, no significant change occurred in AChE activity in tibial posticus and gastrocnemius muscles at day 3. However, a significant decrease was found at day 10, with reductions of 18% and 20% in tibial posticus and gastrocnemius, respectively. At present we cannot explain this change in AChE activity. While temporally different, the direction of the change was similar to that described for rats. This similarity indicates that bullfrog is a valid model for investigating AChE activity following SNT.

Resumo A transecção do nervo isquiático (SNT), um modelo para estudar dor neuropática, simula os sintomas clínicos do "membro fantasma", uma condição dolorosa que ocorre nos humanos após amputação ou secção completa da medula espinal. Essa condição muda a atividade da acetilcolinesterase (AChE), a enzima responsável pela rápida hidrólise da acetilcolina liberada nas sinapses colinérgicas, em alguns tecidos de vertebrados. Em medula espinal de rã Rana pipiens, a atividade da AChE não foi significativamente alterada nos primeiros dias após a secção da raiz ventral, outro modelo para o estudo da dor neuropática. Uma questão ainda não respondida é se a SNT diminui a atividade da AChE na medula espinal de rã Lithobates catesbeianus, uma espécie que vem sendo usada como modelo em estudos da dor neuropática induzida por SNT. Como cada modelo animal é criado a partir de metodologia específica, e seus resultados tendem a variar com pequenas mudanças na metodologia de indução da dor, o presente estudo avaliou a atividade da AChE em medula espinal lombossacral de rã-touro Lithobates catesbeianus, adultos, machos, 3 e 10 dias após a completa SNT. Como há diferenças temporais na maturação de placas motoras em músculos esqueléticos de ratos, nosso estudo ainda demonstrou, na rã-touro, os efeitos da SNT sobre a atividade da AChE nos músculos esqueléticos tibial posticus, um músculo postural, e gastrocnêmio, um músculo frequentemente usado em estudos do sistema motor. A atividade da AChE não mudou significativamente na medula espinal aos 3 e 10 dias após a SNT. Nos músculos, a atividade não alterou significativamente aos 3 dias após a lesão, mas reduziu de forma significativa aos 10 dias após a SNT. Aos 10 dias, a diminuição foi 18% no músculo tibial posticus e 20% no gastrocnêmio. No momento, nós não temos explicação para essa mudança na atividade da AChE. Embora temporalmente diferente, o sentido da mudança é similar ao que é descrito em ratos. Esta similaridade torna a rã-touro um modelo válido para se estudar questões ainda não respondidas da SNT sobre a AChE.

The study of skeletal muscle relaxant property of pheniramine maleate in acetylcholine induced contractions on isolated frog rectus muscle

Background: A muscle relaxant is a drug which affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasm, pain and hyperreflexia. Skeletal muscle relaxants are heterogeneous group of medications that refer to 2 major therapeutic groups: neuromuscular blockers and spasmolytics. This study is carried out to evaluate the skeletal muscle property of Pheniramine maleate in Acetylcholine Induced Contractions on Isolated Frog Rectus Muscle.Methods: There are various screening techniques available to assess the muscle relaxant property of a drug. For initial screening, frog rectus muscle is used. Here frogs are divided into 4 different groups. Each group contains 6 isolated frog rectus muscles. The experiment is carried out by adding 100?g, 200?g, 400?g and 800?g of pheniramine maleate with 80?g of acetylcholine to the organ bath and response is recorded by kymograph.Results: Pheniramine maleate in various doses like 100?g, 200?g, 400?g and 800?g with 80?g of acetylcholine 100?g showed the maximum contractions of frog rectus muscle in kymograph. At all the doses of Pheniramine maleate, it showed a significant effect of skeletal muscle relaxant property.Conclusions: In conclusion with work done by using pheniramine maleate in different doses along with 80?g of acetylcholine. Pheniramine maleate showed the maximum skeletal muscle relaxant property on frog rectus muscle at 800?g dose.

Acetylcholine produces contractions mediated by the cyclooxygenase pathway in arterial vessels in the Chilean frog (Calyptocephalella gayi) / Acetilcolina produz contrações mediadas pela via da ciclooxigenase em vasos arteriais da rã chileno (Calyptocephalella gayi)

Abstract Previous studies performed in marine fish (I. conceptionis and G. laevifrons) showed that indomethacin blocked arterial contraction mediated by acetylcholine (ACh). The objective of this study was to determine if contraction induced by acetylcholine is mediated by the cyclooxygenase pathway in several arterial vessels in the Chilean frog Calyptocephalella gayi. Arteries from the pulmonary (PA), dorsal (DA), mesenteric (MA) and iliac (IA) regions were dissected from 6 adult specimens, and isometric tension studies were done using dose response curves (DRC) for ACh (10-13 to 10-3 M) in presence of a muscarinic antagonist (Atropine 10-5 M) and an unspecific inhibitor of cyclooxygenases (Indomethacin, 10-5M). All the studied arteries exhibited vasoconstriction mediated by ACh. This vasoconstriction was abolished in the presence of atropine in DA, MA and IA and attenuated in PA. Indomethacin abolished the vasoconstriction in MA and attenuated the response in PA, DA and IA. Similar to marine fish, C. gayi have an ACh-mediated vasoconstrictor pattern regulated by muscarinic receptors that activate a cyclooxygenase contraction pathway. These results suggest that the maintenance in vasoconstrictor mechanisms mediated by ACh→COX →vasoconstriction is conserved from fish to frogs.

Resumo Estudos feitos em peixes marinhos (I. conceptionis e G. laevifrons) têm demostrado que a indometacina bloqueia a contração arterial mediada por acetilcolina (ACh). O objetivo do presente estudo foi avaliar o efeito da via da ciclooxigenase na contração induzida por ACh em vasos arteriais da rã chilena Calyptocephalella gayi. Foram dissecadas regiões das artérias pulmonares (PA), dorsal (DA), mesentérica (MA) e ilíaca (IA) de seis espécimes adultos e realizados estudos de tensão isométrica utilizando curvas dose-resposta (CDR) de ACh (10-13 a 10-3 M) na presença de um antagonista muscarínico (atropina, 10-5 M) e um inibidor das ciclooxigenases (indometacina, 10-5 M). Todas as artérias evidenciaram uma resposta vasoconstritora mediada por ACh. Esta resposta vasoconstrictora foi suprimida na presença de atropina nas artérias DA, MA, IA e atenuada na PA. A indometacina suprimiu a vasoconstrição na artéria MA e atenuou a resposta nas artérias PA, DA e IA. Tal como os peixes marinhos, a C. gayi tem um padrão de vasoconstrição mediado por Ach que é regulado pelos receptores muscarínicos e pela ciclooxigenase. Estes resultados sugerem a conservação dos mecanismos vasoconstrictores mediados por ACh→COX em peixes e rãs.

The peculiar breeding biology of the Amazonian frog Allobates subfolionidificans (Aromobatidae)

ABSTRACT Allobates subfolionidificans is a vulnerable and endemic leaf-litter frog from the state of Acre, Brazilian Amazonia. We monitored a population of A. subfolionidificans through regular censuses and mark-recapture of 181 individuals during an entire breeding season to characterize its reproductive behavior. The space use of A. subfolionidificans individuals differed between sexes, with males using smaller and more segregated spaces. Males defended territories and were aggressive against same-sex individuals, which was not the case in females. The daily cycle of calling activity showed peaks in the morning and in the afternoon, and the occurrence of reproductive events was positively correlated with monthly rainfall. The breeding behavior comprised vocal and tactile interactions, although the species lacked reproductive amplexus. Egg and larvae attendance, as well as tadpole transport to water environments was performed mostly by males but occasionally by females, probably in cases of desertion by the father. This species is characterized by performing courtship, mating, oviposition, as well as egg and larvae attendance exclusively on the under surface of leaves, a unique behavior among members of the superfamily Dendrobatoidea.

Effect of Sciatic Nerve Transection on acetylcholinesterase activity in spinal cord and skeletal muscles of the bullfrog Lithobates catesbeianus

Abstract Sciatic nerve transection (SNT), a model for studying neuropathic pain, mimics the clinical symptoms of phantom limb, a pain condition that arises in humans after amputation or transverse spinal lesions. In some vertebrate tissues, this condition decreases acetylcholinesterase (AChE) activity, the enzyme responsible for fast hydrolysis of released acetylcholine in cholinergic synapses. In spinal cord of frog Rana pipiens, this enzymes activity was not significantly changed in the first days following ventral root transection, another model for studying neuropathic pain. An answerable question is whether SNT decreases AChE activity in spinal cord of frog Lithobates catesbeianus, a species that has been used as a model for studying SNT-induced neuropathic pain. Since each animal model has been created with a specific methodology, and the findings tend to vary widely with slight changes in the method used to induce pain, our study assessed AChE activity 3 and 10 days after complete SNT in lumbosacral spinal cord of adult male bullfrog Lithobates catesbeianus. Because there are time scale differences of motor endplate maturation in rat skeletal muscles, our study also measured the AChE activity in bullfrog tibial posticus (a postural muscle) and gastrocnemius (a typical skeletal muscle that is frequently used to study the motor system) muscles. AChE activity did not show significant changes 3 and 10 days following SNT in spinal cord. Also, no significant change occurred in AChE activity in tibial posticus and gastrocnemius muscles at day 3. However, a significant decrease was found at day 10, with reductions of 18% and 20% in tibial posticus and gastrocnemius, respectively. At present we cannot explain this change in AChE activity. While temporally different, the direction of the change was similar to that described for rats. This similarity indicates that bullfrog is a valid model for investigating AChE activity following SNT.

Resumo A transecção do nervo isquiático (SNT), um modelo para estudar dor neuropática, simula os sintomas clínicos do membro fantasma, uma condição dolorosa que ocorre nos humanos após amputação ou secção completa da medula espinal. Essa condição muda a atividade da acetilcolinesterase (AChE), a enzima responsável pela rápida hidrólise da acetilcolina liberada nas sinapses colinérgicas, em alguns tecidos de vertebrados. Em medula espinal de rã Rana pipiens, a atividade da AChE não foi significativamente alterada nos primeiros dias após a secção da raiz ventral, outro modelo para o estudo da dor neuropática. Uma questão ainda não respondida é se a SNT diminui a atividade da AChE na medula espinal de rã Lithobates catesbeianus, uma espécie que vem sendo usada como modelo em estudos da dor neuropática induzida por SNT. Como cada modelo animal é criado a partir de metodologia específica, e seus resultados tendem a variar com pequenas mudanças na metodologia de indução da dor, o presente estudo avaliou a atividade da AChE em medula espinal lombossacral de rã-touro Lithobates catesbeianus, adultos, machos, 3 e 10 dias após a completa SNT. Como há diferenças temporais na maturação de placas motoras em músculos esqueléticos de ratos, nosso estudo ainda demonstrou, na rã-touro, os efeitos da SNT sobre a atividade da AChE nos músculos esqueléticos tibial posticus, um músculo postural, e gastrocnêmio, um músculo frequentemente usado em estudos do sistema motor. A atividade da AChE não mudou significativamente na medula espinal aos 3 e 10 dias após a SNT. Nos músculos, a atividade não alterou significativamente aos 3 dias após a lesão, mas reduziu de forma significativa aos 10 dias após a SNT. Aos 10 dias, a diminuição foi 18% no músculo tibial posticus e 20% no gastrocnêmio. No momento, nós não temos explicação para essa mudança na atividade da AChE. Embora temporalmente diferente, o sentido da mudança é similar ao que é descrito em ratos. Esta similaridade torna a rã-touro um modelo válido para se estudar questões ainda não respondidas da SNT sobre a AChE.

Metodologia de abate de girinos de rã-touro para obtenção de filés de cauda e subprodutos não comestíveis

O objetivo do presente trabalho foi estabelecer uma metodologia para abate de girinos, com foco na obtenção de filés de cauda para a produção de alimentos e da parte não comestível para a fabricação de farinha animal. As operações de abate foram realizadas em planta industrial sob inspeção sanitária oficial. Um total de 1.600 girinos pesando 13,55±6,67g foram submetidos a um jejum de 24 horas e em seguida coletados e transportados até a planta industrial, onde foram transferidos para caixas plásticas para depuração. As etapas tecnológicas de abate foram pré-insensibilização, lavagem, inspeção, decapitação e corte de cauda, produção dos filés de cauda, lavagem, embalagem da cauda e da parte não comestível, selagem, pré-resfriamento, congelamento rápido, estocagem e distribuição. O rendimento da parte não comestível foi de 73,49±5,51% em relação ao peso total, enquanto que o rendimento dos filés de cauda representou 26,51±5,51% do peso total. O método desenvolvido mostrou-se eficaz para a obtenção dos produtos propostos, com bom rendimento percentual para ambas matrizes obtidas.