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1.
J Anat ; 232(3): 497-508, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29205335

RESUMO

Melanomacrophages are phagocytes that synthesize melanin. They are found in the liver and spleen of ectothermic vertebrates, and in the kidney of fish. In agnathan and elasmobranch fish, melanomacrophages are seen as isolated cells, and forming clusters in all the other vertebrates. The natural phagocytic activity of melanomacrophages is poorly characterized, as most of the research works have focused on induced phagocytic activity only. Furthermore, little is known about amphibian melanomacrophages, mainly about those in caecilians - wormlike amphibians in the order of Gymnophiona, which is the least known group of terrestrial vertebrates. The present research work aimed at the structure and function of hepatic melanomacrophages of Siphonops annulatus, a species largely found in South America. We identified the role of these cells in the control of circulating basophils (pro-melanogenic cells), in the turnover of liver collagen stroma and in the hemocatheresis, interrelated physiological mechanisms.


Assuntos
Anfíbios , Fígado/citologia , Macrófagos/citologia , Animais , Macrófagos/metabolismo , Melaninas/biossíntese
2.
Front Zool ; 15: 46, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30479646

RESUMO

BACKGROUND: Amphibian defence against predators and microorganisms is directly related to cutaneous glands that produce a huge number of different toxins. These glands are distributed throughout the body but can form accumulations in specific regions. When grouped in low numbers, poison glands form structures similar to warts, quite common in the dorsal skin of bufonids (toads). When accumulated in large numbers, the glands constitute protuberant structures known as macroglands, among which the parotoids are the most common ones. This work aimed at the morphological and biochemical characterization of the poison glands composing different glandular accumulations in four species of toads belonging to group Rhinella marina (R. icterica, R. marina, R. schneideri and R. jimi). These species constitute a good model since they possess other glandular accumulations together with the dorsal warts and the parotoids and inhabit environments with different degrees of water availability. RESULTS: We have observed that the toads skin has three types of poison glands that can be differentiated from each other through the morphology and the chemical content of their secretion product. The distribution of these different glands throughout the body is peculiar to each toad species, except for the parotoids and the other macroglands, which are composed of an exclusive gland type that is usually different from that composing the dorsal warts. Each type of poison gland presents histochemical and biochemical peculiarities, mainly regarding protein components. CONCLUSIONS: The distribution, morphology and chemical composition of the different types of poison glands, indicate that they may have different defensive functions in each toad species.

3.
Mol Biotechnol ; 66(2): 354-364, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37162721

RESUMO

This work aimed to assess the Sf9 cell metabolism during growth, and infection steps with recombinant baculovirus bearing rabies virus proteins, to finally obtain rabies VLP in two culture systems: Schott flask (SF) and stirred tank reactor (STR). Eight assays were performed in SF and STR (four assays in each system) using serum-free SF900 III culture medium. Two non-infection growth kinetics assays and six recombinant baculovirus infection assays. The infection runs were carried out at 0.1 pfu/cell multiplicity of infection (MOI) for single baculovirus bearing rabies glycoprotein (BVG) and matrix protein (BVM) and a coinfection with both baculoviruses at MOI of 3 and 2 pfu/cell for BVG and BVM, respectively. The SF assays were done in triplicate. The glucose, glutamine, glutamate, lactate, and ammonium uptake or release specific rates were quantified over the exponential growth phase and infection stage. The highest uptake specific rate was observed for glucose (42.5 × 10-12 mmol cell/h) in SF and for glutamine (30.8 × 10-12 mmol/cell/h) in STR, in the exponential growth phases. A wave pattern was observed for assessed analytes throughout the infection phase and the glucose had the highest wave amplitude within the 10-10 mmol cell/h order. This alternative uptake and release behavior is in harmony with the lytic cycle of baculovirus in insect cells. The virus propagation and VLP generation were not limited by glucose, glutamine, and glutamate, neither by the toxicity of lactate nor ammonium under the conditions appraised in this work. The findings from this work can be useful to set baculovirus infection processes at high cell density to improve rabies VLP yield, purity, and productivity.


Assuntos
Compostos de Amônio , Vírus da Raiva , Raiva , Animais , Células Sf9 , Vírus da Raiva/genética , Glutamina , Baculoviridae/genética , Proteínas Recombinantes/genética , Meios de Cultura Livres de Soro , Ácido Glutâmico , Lactatos , Glucose , Spodoptera
4.
Exp Parasitol ; 135(4): 655-60, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24113627

RESUMO

Nature has provided inspiration for Drug Discovery studies and amphibian secretions have been used as a promising source of effective peptides which could be explored as novel drug prototypes for neglected parasitic diseases as Leishmaniasis and Chagas disease. In this study, we isolated four antimicrobial peptides (AMPs) from Phyllomedusa nordestina secretion, and studied their effectiveness against Leishmania (L.) infantum and Trypanosoma cruzi. The antiparasitic fractions were characterized by mass spectrometry and Edman degradation, leading to the identification of dermaseptins 1 and 4 and phylloseptins 7 and 8. T. cruzi trypomastigotes were susceptible to peptides, showing IC50 values in the range concentration of 0.25-0.68 µM. Leishmania (L.) infantum showed susceptibility to phylloseptin 7, presenting an IC50 value of 10 µM. Except for phylloseptin 7 which moderate showed cytotoxicity (IC50=34 µM), the peptides induced no cellular damage to mammalian cells. The lack of mitochondrial oxidative activity of parasites detected by the MTT assay, suggested that peptides were leishmanicidal and trypanocidal. By using the fluorescent probe SYTOX(®) Green, dermaseptins 1 and 4 and phylloseptins 7 and 8 showed time-dependent plasma membrane permeabilization of T. cruzi; phylloseptin 7 also showed a similar effect in Leishmania parasites. The present study demonstrates for the first time that AMPs target the plasma membrane of Leishmania and T. cruzi, leading to cellular death. Considering the potential of amphibian peptides against protozoan parasites and the reduced mammalian toxicity, they may contribute as scaffolds for drug design studies.


Assuntos
Proteínas de Anfíbios/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Antiprotozoários/farmacologia , Anuros/metabolismo , Leishmania infantum/efeitos dos fármacos , Trypanosoma cruzi/efeitos dos fármacos , Proteínas de Anfíbios/isolamento & purificação , Proteínas de Anfíbios/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/metabolismo , Antiprotozoários/isolamento & purificação , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Cricetinae , Feminino , Fluorometria , Leishmania infantum/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Espectrometria de Massas , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Análise de Sequência de Proteína , Trypanosoma cruzi/metabolismo
5.
Front Pharmacol ; 14: 1181566, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37377933

RESUMO

Introdutcion: The Zika virus (ZIKV) infections are a healthcare concern mostly in the Americas, Africa, and Asia but have increased its endemicity area beyond these geographical regions. Due to the advances in infections by Zika virus, it is imperative to develop diagnostic and preventive tools against this viral agent. Virus-like particles (VLPs) appear as a suitable approach for use as antiviral vaccines. Methods: In this work, a methodology was established to produce virus-like particles containing the structural proteins, C, prM, and E of Zika virus produced in insect cells using the gene expression system derived from baculovirus. The vector pFast- CprME -ZIKV was constructed containing the gene sequences of Zika virus structural proteins and it was used to generate the recombinant bacmids (Bac- CprME -ZIKV) through transformation into DH10BacTM cells. The Bac- CprME -ZIKV was transfected in Spodoptera frugiperda (Sf9) insect cells and batches of BV- CprME -ZIKV were obtained by infection assays using a multiplicity of infection of 2. The Sf9 cells were infected, and the supernatant was collected 96 h post-infection. The expression of the CprME -ZIKV protein on the cell surface could be observed by immunochemical assays. To concentrate and purify virus-like particles, the sucrose and iodixanol gradients were evaluated, and the correct CprME -ZIKV proteins' conformation was evaluated by the Western blot assay. The virus-like particles were also analyzed and characterized by transmission electron microscopy. Results and discussion: Spherical structures like the native Zika virus from 50 to 65 nm containing the CprME -ZIKV proteins on their surface were observed in micrographs. The results obtained can be useful in the development path for a vaccine candidate against Zika virus.

6.
iScience ; 25(4): 104073, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35372815

RESUMO

Despite the common poison and mucous glands, some amphibian groups have differentiated glands associated with reproduction and usually present on the male ventral surface. Known as breeding glands or sexually dimorphic skin glands (SDSGs), they are related to intraspecific chemical communication during mating. Until recently, reproduction associated with skin glands was recognized only in salamanders and caecilians and remained unexplored among anurans. The Brazilian microhylid Dermatonotus muelleri (Muller's termite frog) is known for its very toxic skin secretion. Despite the slippery body, the male adheres to the female back during reproduction, as they have differentiated ventral glands. In this paper, we have gathered data proposing an integrative approach correlated with the species' biology and biochemical properties of their skin secretions. Furthermore, we suggest that the adhesion phenomenon is related to arm shortening and rounded body that make amplexus inefficient, although constituting important adaptive factors to life underground.

7.
Vaccines (Basel) ; 11(1)2022 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-36679884

RESUMO

This work aimed to assess, following upstream optimization in Schott flasks, the scalability from this culture platform to a stirred-tank bioreactor in order to yield rabies-recombinant baculovirus, bearing genes of G (BVG) and M (BVM) proteins, and to obtain rabies virus-like particles (VLP) from them, using Sf9 insect cells as a host. Equivalent assays in Schott flasks and a bioreactor were performed to compare both systems and a multivariate statistical approach was also carried out to maximize VLP production as a function of BVG and BVM's multiplicity of infection (MOI) and harvest time (HT). Viable cell density, cell viability, virus titer, BVG and BVM quantification by dot-blot, and BVG quantification by Enzyme-Linked Immunosorbent Assay (ELISA) were monitored throughout the assays. Furthermore, transmission electron microscopy was used to characterize rabies VLP. The optimal combination for maximum VLP expression was BVG and BVM MOI of 2.3 pfu/cell and 5.1 pfu/cell, respectively, and 108 h of harvest time. The current study confirmed that the utilization of Schott flasks and a benchtop bioreactor under the conditions applied herein are equivalent regarding the cell death kinetics corresponding to the recombinant baculovirus infection process in Sf9 cells. According to the results, the hydrodynamic and chemical differences in both systems seem to greatly affect the virus and VLP integrity after release.

8.
Toxins (Basel) ; 13(11)2021 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-34822563

RESUMO

Caecilians (order Gymnophiona) are apodan, snake-like amphibians, usually with fossorial habits, constituting one of the most unknown groups of terrestrial vertebrates. As in orders Anura (frogs, tree frogs and toads) and Caudata (salamanders and newts), the caecilian skin is rich in mucous glands, responsible for body lubrication, and poison glands, producing varied toxins used in defence against predators and microorganisms. Whereas in anurans and caudatans skin gland morphology has been well studied, caecilian poison glands remain poorly elucidated. Here we characterised the skin gland morphology of the caecilian Siphonops annulatus, emphasising the poison glands in comparison to those of anurans and salamanders. We showed that S. annulatus glands are similar to those of salamanders, consisting of several syncytial compartments full of granules composed of protein material but showing some differentiated apical compartments containing mucus. An unusual structure resembling a mucous gland is frequently observed in lateral/apical position, apparently connected to the main duct. We conclude that the morphology of skin poison glands in caecilians is more similar to salamander glands when compared to anuran glands that show a much-simplified structure.


Assuntos
Anfíbios/anatomia & histologia , Glândulas Exócrinas/anatomia & histologia , Animais , Feminino , Masculino , Muco/metabolismo , Venenos/metabolismo
9.
Mol Biotechnol ; 63(11): 1068-1080, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34228257

RESUMO

Rabies is an ancient zoonotic disease that still causes the death of over 59,000 people worldwide each year. The rabies lyssavirus encodes five proteins, including the envelope glycoprotein and the matrix protein. RVGP is the only protein exposed on the surface of viral particle, and it can induce immune response with neutralizing antibody formation. RVM has the ability to assist with production process of virus-like particles. VLPs were produced in recombinant baculovirus system. In this work, two recombinant baculoviruses carrying the RVGP and RVM genes were constructed. From the infection and coinfection assays, we standardized the best multiplicity of infection and the best harvest time. Cell supernatants were collected, concentrated, and purified by sucrose gradient. Each step was used for protein detection through immunoassays. Sucrose gradient analysis enabled to verify the separation of VLPs from rBV. Through the negative contrast technique, we visualized structures resembling rabies VLPs produced in insect cells and rBV in the different fractions of the sucrose gradient. Using ELISA to measure total RVGP, the recovery efficiency of VLPs at each stage of the purification process was verified. Thus, these results encourage further studies to confirm whether rabies VLPs are a promising candidate for a veterinary rabies vaccine.


Assuntos
Baculoviridae/genética , Insetos/metabolismo , Vacina Antirrábica/biossíntese , Vírus da Raiva/metabolismo , Raiva/virologia , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Animais , Baculoviridae/isolamento & purificação , Baculoviridae/metabolismo , Células Cultivadas , Humanos , Insetos/imunologia , Insetos/virologia , Vacina Antirrábica/genética , Vacina Antirrábica/imunologia , Vacina Antirrábica/isolamento & purificação , Vírus da Raiva/imunologia , Vírus da Raiva/isolamento & purificação , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas de Partículas Semelhantes a Vírus/isolamento & purificação
10.
Toxicon X ; 6: 100033, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32550588

RESUMO

Amphibian cutaneous glands secrete toxins used in different vital functions including passive defense. Through Desorption Electrospray Ionization-Imaging we analyzed the distribution of the major toxins of the toad Rhinella marina parotoid macroglands. Alkaloids and steroids showed characteristic distribution and intensity within the glands and were also present at lower levels on the skin surface. A comprehensive overview of toxins distribution in toads' skin might help to understand their full biological role within the amphibians.

11.
Toxicon ; 178: 4-7, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32081637

RESUMO

In recent years, SE Brazil, the most populous region in the country with an estimated population of 88 million, has been experiencing an alarming increase in scorpions accidents (scorpionism), mainly caused by the yellow scorpion (Tityus serrulatus), or "escorpião amarelo" in Portuguese. This species is considered particularly dangerous to humans and can reproduce by parthenogenesis favouring rapid dispersal and colonization of new environments. Since the 1940s, owing to the growing danger represented by scorpionism, public control policies have been developed, including active search for scorpions, together with the use of toxic substances applied in places most likely to serve as their refuges. Even so, the number of accidents is increasing year by year, presently at an alarming rate. It seems evident that the increase in accidents is directly (or primarily) related to the lack of predators that in healthy environmental conditions would naturally control scorpion populations. However, due to environmental changes, leading to a lack of predators, scorpions have been gradually invading the urban environment. Arachnids and insects in general, as well as some other invertebrates, are preyed upon by anuran amphibians (toads, frogs and tree frogs). Toads (family Bufonidae) are nocturnal, large, and highly voracious animals, capable of actively exploring extensive areas and consuming large numbers of insects and arachnids daily. One of the most common toad species in southeastern Brazil is Rhinella icterica. Both R. icterica and T. serrulatus inhabit the same nocturnal environment. The predatory action of toads, specifically on scorpions, is practically unknown from behavioural and toxinological points of view. Thus, we studied the predatory behaviour of this toad against the yellow scorpion and evaluated the resistance of the amphibian to scorpion venom. Our results show that R. icterica is a voracious predator of T. serrulatus and is extremely resistant to its venom. Human/toad relationship throughout western history has always been very conflicted and possibly one of the factors that most has contributed to human ignorance of the role of these amphibians in maintaining ecological balance. Presently, the control of scorpionism is being performed through active search and/or the use of chemical agents, although showing little efficacy in reducing human accidents. In the medium or long term, more effective actions taking into account the biology of scorpions and their predators have never been taken to reduce these accidents.


Assuntos
Bufonidae/fisiologia , Picadas de Escorpião/epidemiologia , Venenos de Escorpião , Escorpiões , Animais , Brasil/epidemiologia , Humanos , Controle Biológico de Vetores/métodos
12.
iScience ; 23(7): 101234, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32621800

RESUMO

Amphibians are known for their skin rich in glands containing toxins employed in passive chemical defense against predators, different from, for example, snakes that have active chemical defense, injecting their venom into the prey. Caecilians (Amphibia, Gymnophiona) are snake-shaped animals with fossorial habits, considered one of the least known vertebrate groups. We show here that amphibian caecilians, including species from the basal groups, besides having cutaneous poisonous glands as other amphibians do, possess specific glands at the base of the teeth that produce enzymes commonly found in venoms. Our analysis of the origin of these glands shows that they originate from the same tissue that gives rise to teeth, similar to the venom glands in reptiles. We speculate that caecilians might have independently developed mechanisms of production and injection of toxins early in their evolutionary history.

13.
Exp Neurol ; 332: 113390, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32598929

RESUMO

Because environmental elements modify chronic pain development and endogenous mechanisms of pain control are still a great therapeutic source, we investigated the effects of an early exposure to environmental enrichment (EE) in a translational model of neuropathic pain. Young male rats born and bred in an enriched environment, which did not count on running wheel, underwent chronic constriction injury (CCI) of sciatic nerve. EE abolished neuropathic pain behavior 14 days after CCI. Opioid receptors' antagonism reversed EE-analgesic effect. ß-endorphin and met-enkephalin serum levels were increased only in EE-CCI group. Blockade of glucocorticoid receptors did not alter EE-analgesic effect, although corticosterone circulating levels were increased in EE animals. In the spinal cord, EE controlled CCI-induced serotonin increase. In DRG, EE blunted the expression of ATF-3 after CCI. Surprisingly, EE-CCI group showed a remarkable preservation of sciatic nerve fibers compared to NE-CCI group. This work demonstrated global effects induced by an EE protocol that explain, in part, the protective role of EE upon chronic noxious stimulation, reinforcing the importance of endogenous mechanisms in the prevention of chronic pain development.


Assuntos
Meio Ambiente , Neuralgia/prevenção & controle , Traumatismos dos Nervos Periféricos/complicações , Nervo Isquiático/lesões , Animais , Sobrevivência Celular , Constrição Patológica , Endorfinas/sangue , Encefalinas/sangue , Hiperalgesia/patologia , Masculino , Fibras Nervosas/patologia , Neuralgia/etiologia , Neuralgia/patologia , Traumatismos dos Nervos Periféricos/patologia , Ratos , Ratos Wistar , Receptores de Glucocorticoides/metabolismo , Nervo Isquiático/patologia , Medula Espinal/metabolismo , Suporte de Carga
14.
Sci Rep ; 9(1): 18490, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811169

RESUMO

Tetrodotoxin (TTX), one of the most toxic substances in nature, is present in bacteria, invertebrates, fishes, and amphibians. Marine organisms seem to bioaccumulate TTX from their food or acquire it from symbiotic bacteria, but its origin in amphibians is unclear. Taricha granulosa can exhibit high TTX levels, presumably concentrated in skin poison glands, acting as an agent of selection upon predatory garter snakes (Thamnophis). This co-evolutionary arms race induces variation in T. granulosa TTX levels, from very high to undetectable. Using morphology and biochemistry, we investigated differences in toxin localization and quality between two populations at the extremes of toxicity. TTX concentration within poison glands is related to the volume of a single cell type in which TTX occurs exclusively in distinctive secretory granules, suggesting a relationship between granule structure and chemical composition. TTX was detected in mucous glands in both populations, contradicting the general understanding that these glands do not secrete defensive chemicals and expanding currently held interpretations of amphibian skin gland functionality. Skin secretions of the two populations differed in low-mass molecules and proteins. Our results demonstrate that interpopulation variation in TTX levels is related to poison gland morphology.


Assuntos
Salamandridae , Pele/química , Tetrodotoxina/análise , Animais , Evolução Biológica
15.
Toxicon ; 51(5): 898-913, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18262581

RESUMO

Although snake infralabial glands are generally constituted of mucous cells, among dipsadines, they are much more developed and predominantly serous in nature, possibly due to the peculiar feeding habits of some species of this group, the "goo-eaters", which feed on soft and viscous invertebrates. We compared the morphology and histochemistry of the infralabial glands of three goo-eater species of Southeast Brazil, Atractus reticulatus, Dipsas indica and Sibynomorphus mikanii. In A. reticulatus the glands are formed by mixed acini composed of mucous and seromucous cells and in D. indica, they are composed of mucous tubules and seromucous acini. In S. mikanii the glands are organized in seromucous acini; mucous cells are restricted to the gland anterior region and to the duct lining epithelium. Ultrastructurally, secretory granule electron density varies from low to moderate, depending on their mucous or seromucous nature. The results indicate a large morphological and histochemical variation in the infralabial glands, probably reflecting differences in the secretion chemical composition and in feeding specialization among the three species. The protein content in the secretory cells can be related with the presence of toxins that can be used in chemical prey immobilization or detaching of snails from their shells.


Assuntos
Colubridae/anatomia & histologia , Colubridae/metabolismo , Boca/anatomia & histologia , Animais , Comportamento Alimentar , Feminino , Histocitoquímica/veterinária , Masculino , Microscopia Eletrônica de Transmissão/veterinária , Glândulas Salivares Menores/anatomia & histologia , Glândulas Salivares Menores/ultraestrutura
16.
Toxicon ; 52(1): 13-21, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18588907

RESUMO

Amphibian skin secretions are considered a rich source of biologically active compounds and are known to be rich in peptides, bufadienolides and alkaloids. Bufadienolides are cardioactive steroids from animals and plants that have also been reported to possess antimicrobial activities. Leishmaniasis and American Trypanosomiasis are parasitic diseases found in tropical and subtropical regions. The efforts toward the discovery of new treatments for these diseases have been largely neglected, despite the fact that the only available treatments are highly toxic drugs. In this work, we have isolated, through bioguided assays, the major antileishmanial compounds of the toad Rhinella jimi parotoid macrogland secretion. Mass spectrometry and (1)H and (13)C NMR spectroscopic analyses were able to demonstrate that the active molecules are telocinobufagin and hellebrigenin. Both steroids demonstrated activity against Leishmania (L.) chagasi promastigotes, but only hellebrigenin was active against Trypanosoma cruzi trypomastigotes. These steroids were active against the intracellular amastigotes of Leishmania, with no activation of nitric oxide production by macrophages. Neither cytotoxicity against mouse macrophages nor hemolytic activities were observed. The ultrastructural studies with promastigotes revealed the induction of mitochondrial damage and plasma membrane disturbances by telocinobufagin, resulting in cellular death. This novel biological effect of R. jimi steroids could be used as a template for the design of new therapeutics against Leishmaniasis and American Trypanosomiasis.


Assuntos
Bufanolídeos/farmacologia , Bufonidae/metabolismo , Leishmania infantum/efeitos dos fármacos , Glândula Parótida/metabolismo , Tripanossomicidas/farmacologia , Animais , Bufanolídeos/química , Bufanolídeos/isolamento & purificação , Cricetinae , Macrófagos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/biossíntese , Trypanosoma cruzi/efeitos dos fármacos
17.
Sci Rep ; 8(1): 3576, 2018 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-29476100

RESUMO

Amphibian skin is rich in mucous glands and poison glands, secreting substances important for gas exchange and playing a fundamental role in chemical defense against predators and microorganisms. In the caecilian Siphonops annulatus (Mikan, 1920) we observed a concentration of enlarged mucous glands in the head region. In the posterior region of the body a similar concentration is made up of enlarged poison glands. These accumulations of glands structurally resemble the macroglands previously reported in anurans and salamanders. The skin glands in these regions are each surrounded by collagen walls forming a honeycomb-like structure. The collagen network in the head region firmly attaches to tiny pits in the bones of the skull. The two extremities of the body produce different secretions, containing exclusive molecules. Considering the fossorial lifestyle of caecilians, it seems evident that the secretions of the head and caudal region serve different functions. The anterior macrogland of mucous glands, rich in mucous/lipid secretion, in conjunction with the funnel-shaped head, may act to lubricate the body and penetrate the soil, thus facilitating locomotion underground. The blunt posterior end bearing an internalized macrogland of poison glands in the dermis may act in chemical defense and/or by blocking invasion of tunnels.


Assuntos
Anuros/fisiologia , Evolução Biológica , Glândulas Exócrinas/fisiologia , Fenômenos Fisiológicos da Pele , Animais , Anuros/metabolismo , Secreções Corporais/fisiologia , Derme/fisiologia , Glândulas Exócrinas/metabolismo , Venenos/metabolismo , Pele/química , Pele/metabolismo , Crânio/fisiologia
18.
Toxicon ; 130: 127-135, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28249803

RESUMO

Dermatonotus muelleri is the sole species of the Dermatonotus genus and inhabits Argentina, Bolivia, Brazil and Paraguay. This animal exhibits an explosive reproductive behavior during the Southern spring months, which lasts only for five days. Moreover, this animal displays specific adaptations to the habitat resulting in the energy conservation needed during either the intense reproduction period or times of estivation. During dry seasons and/or food shortages D. muelleri can survive because its food specialization and ability to dig an underground chamber for protection. Few literature is available on this amphibian and no biochemical characterization has ever been performed on the animal's skin secretion. This work, on the other hand, presents for the first time a venomic analysis of the major components present in the skin secretion of this microhylid. The crude skin secretion was obtained my mechanical stimulation and was analyzed according to one major criterion: >10 kDa or <10 kDa. The high molecular mass fraction was subjected to typical gel-based proteomic processing whereas the low molecular mass fraction was analyzed by liquid chromatography, mass spectrometry and nuclear magnetic resonance (NMR), yielding an overall 'venomics' approach. No classical/evident toxin was detected, but peptidases (metallo and serino) and structural proteins could be identified. In the low molecular mass fraction no peptides were detected, as well as no typical alkaloid or steroid. On the other hand, the amino acid tryptophan could be identified and a typical sugar spectrum was obtained in the NMR analyses. Altogether these findings point out to the fact that D. muelleri skin secretion is unique and the molecular arsenal present herein is yet to be explored; therefore, this venomics study is only the beginning.


Assuntos
Proteínas de Anfíbios/química , Venenos de Anfíbios/química , Anuros/metabolismo , Pele/metabolismo , Proteínas de Anfíbios/farmacologia , Proteínas de Anfíbios/fisiologia , Venenos de Anfíbios/metabolismo , Venenos de Anfíbios/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Escherichia coli/efeitos dos fármacos , Espectrometria de Massas , Metabolômica , Testes de Sensibilidade Microbiana , Micrococcus luteus/efeitos dos fármacos , Ressonância Magnética Nuclear Biomolecular , Proteômica , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
19.
Toxicon ; 129: 123-133, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28235580

RESUMO

Anuran integument is characterized by the presence of glands, some of which are responsible for toxin production. In some species these glands accumulate in parts of the body strategically located against predators, forming structures known as macroglands. This is the case for parotoid macroglands, on the dorsum of the head, tibial macroglands, on the rear limbs, and radial macroglands, on the forelimbs of toads and some other anurans. The toad Rhinella jimi, for example, simultaneously displays all three types of macroglands, which is unusual even among bufonids. Interestingly, considering the phylogenetic distance, the frog Odontophrynus cultripes (Odontophrynidae) also presents these three macroglandular types. In this study we analyze the morphology of O. cultripes macroglands and the chemical composition of their poison using an interdisciplinary approach. In this species, the parotoid, tibial, and radial macroglands consist of aggregates of elongated and juxtaposed poison glands, arranged in a honeycomb style, very similar to that of toads. Comparative analysis of these three macrogland types shows significant differences in both the morphology of secretory granules and biochemical composition. The present work on O. cultripes contributes to the evidence that amphibians, or at least anurans, share a basic design for all cutaneous glandular accumulations. The determinant factor for macroglandular formation may be the selective pressure for defense against predators.


Assuntos
Anuros/fisiologia , Bufonidae/fisiologia , Glândula Parótida/anatomia & histologia , Venenos de Anfíbios/química , Venenos de Anfíbios/metabolismo , Animais , Anuros/classificação , Comportamento Animal , Bufonidae/classificação , Feminino , Masculino , Glândula Parótida/metabolismo , Glândula Parótida/ultraestrutura , Filogenia , Pele/anatomia & histologia , Especificidade da Espécie
20.
Zootaxa ; 3905(3): 425-31, 2015 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-25661220

RESUMO

A new species of siphonopid caecilian, Microcaecilia butantan sp. nov., is described based on four specimens from Belterra, in the State of Pará, Brazil. The new species differs from all other Microcaecilia in having a combination of more than 135 primary annuli and long premaxillary-maxillary tooth series that extend posteriorly beyond the choanae. Some specimens were dug from soil in a cupuaçu (Theobroma grandiflorum) plantation suggesting that this form of agriculture provides an environment suitable for at least some caecilians.


Assuntos
Anfíbios/classificação , Anfíbios/anatomia & histologia , Anfíbios/crescimento & desenvolvimento , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Brasil , Ecossistema , Feminino , Masculino , Tamanho do Órgão
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