An overview of some enzymes from buthid scorpion venoms from Colombia: Centruroides margaritatus, Tityus pachyurus, and Tityus n. sp. aff. metuendus

Background: In Colombia, several species of Buthidae scorpions belonging to the genera Centruroides and Tityus coexist, and their stings are considered life-threatening to humans because of their venom neurotoxins. Despite previous studies focusing on neurotoxins from these scorpion genera, little is known about the enzymes present in their venoms and their relationship with whole venom toxicity. Methods: Here, using proteomic and biochemical protocols the enzymatic activities of the venoms of three Colombian scorpion species, C. margaritatus, T. pachyurus, and T. n. sp. aff. metuendus, were compared to establish the presence and absence of enzymes such as phospholipases, hyaluronidases, and proteases that could be related to venom toxicity. Results: C. margaritatus was positive for hyaluronidases, T. n. sp. aff. metuendus for proteases, and T. pachyurus exhibited activity for all three mentioned enzymes. Conclusion: This information provides valuable insights into the specific enzyme diversity of each species' venom and their potential role in venom toxicity, which could contribute to the development of better treatments and prevention strategies for scorpion envenomation.

Effects of scorpion venom heat-resistant peptide on the hippocampal neurons of kainic acid-induced epileptic rats

Scorpion venom is a Chinese medicine for epilepsy treatment, but the underlying mechanism is not clear. Scorpion venom heat-resistant peptide (SVHRP), a peptide isolated from the venom of Buthus martensii Karsch, has an anti-epileptic effect by reducing seizure behavior according to a modified Racine scale. The present study aimed to investigate the molecular mechanism of SVHRP on temporal lobe epilepsy. The hippocampus and hippocampal neurons from kainic acid-induced epileptic rats were treated with SVHRP at different doses and duration. Quantitative RT-PCR and immunoblotting were used to detect the expression level of brain-derived neurotrophic factor (BDNF), neuropeptide Y (NPY), cAMP-response element binding protein (CREB), stromal interaction molecule (STIM), and calcium release-activated calcium channel protein 1 (ORAI1). In the hippocampal tissues and primary hippocampal neuron cultures, SVHRP treatment resulted in increased mRNA and protein levels of BDNF and NPY under the epileptic condition. The upregulation of BDNF and NPY expression was positively correlated with the dose level and treatment duration of SVHRP in hippocampal tissues from kainic acid-induced epileptic rats. On the other hand, no significant changes in the levels of CREB, STIM, or ORAI1 were observed. SVHRP may exhibit an anti-epileptic effect by upregulating the expression of BDNF and NPY in the epileptic hippocampus.

Accidente causado por Tityus falconensis González-Sponga, 1974 (Scorpiones, Buthidae) en La Peña, Sierra de San Luis, estado Falcón, Venezuela / Accident produced by Tityus falconensis González-Sponga, 1974 (Scorpiones, Buthidae) in La Peña, Sierra de San Luis, Falcon state, Venezuela

Resumen Se describe un accidente causado por Tityus falconensis González-Sponga, 1974 (Scorpiones, Buthidae) en un indi viduo masculino de 48 años de edad. El evento catalogado clínicamente como un envenenamiento sin compromiso sistémico, con solo síntomas y signos locales (edema e hiperemia en halux y parestesia del área plantar del pie derecho); ocurrió en el ambiente antrópico (área de dormitorio) en la localidad rural de La Peña, Sierra de San Luis, estado Falcón, región nor-occidental de Venezuela.

Abstract We report an accident produced by Tityus falconensis González-Sponga, 1974 (Scorpiones, Buthidae) in a 48 years old male patient. The accident was considered clinically as an envenomation with no systemic compliance, with just local signs and symptoms (oedema and hyperemia in the halux and paresthesia of the plantar part of the right foot). The accident took place within the human environment (in dormitory) in the rural community of La Peña, Sierra de San Luis, Falcon state, North-Western region from Venezuela.

Expansión de la distribución de escorpiones del género Tityus C. L. Koch 1836 en Argentina: Implicancias sanitarias / Expansion of the distribution of scorpions of the genus Tityus C. L. Koch 1836 in Argentina: Implications in public health

Se ha observado la presencia de especies de Tityus en diferentes regiones del país, en las cuales su presencia no había sido comunicada previamente: 1- Tityus bahiensis en las provincias de Entre Ríos y Buenos Aires, en esta última en la localidad de Lanús y en San Clemente del Tuyú, y 2- Tityus confluens en la Ciudad Autónoma de Buenos Aires (CABA) y en la provincia de Buenos Aires en las localidades de Pilar, La Plata, Mar del Plata y Bahía Blanca. Estos hallazgos modifican el mapa de la distribución de escorpiones de importancia sanitaria en Argentina por lo que ante la picadura de escorpiones deben considerarse estos nuevos hallazgos. Esto es especialmente importante en el ámbito de la CABA y la provincia de Buenos Aires, en donde la enorme mayoría de los accidentes por escorpiones han sido causados por T. trivittatus y en donde ahora, al menos en algunas de sus regiones se pueden encontrar T. confluens y T. bahiensis. Se discuten posibles razones de esta nueva distribución así como la ocurrencia de accidentes graves en zonas donde no ocurrían históricamente y de sus posibles causas. En base a los casos graves producidos en los últimos tiempos y a este nuevo mapa de distribución, se hace énfasis en la necesidad de capacitación al personal de salud en general y de los médicos de guardia y terapistas en particular, para tratar adecuadamente los accidentes por escorpiones.

Several species of Tityus have been described in regions of Argentina where their presence had not been previously described. These are: 1- Tityus bahiensis in the provinces of Entre Ríos and Buenos Aires (in the localities of Lanús and San Clemente del Tuyú), and 2- Tityus confluens in the city of Buenos Aires and in the province of Buenos Aires in the localities of Pilar, La Plata, Mar del Plata and Bahía Blanca. These findings modify the distribution map of scorpions of sanitary importance in Argentina, reason for which this new distribution must be considered when facing a scorpion sting. This is especially important in the city of Buenos Aires and the province of Buenos Aires, where most of the accidents by scorpions are caused by Tityus trivittatus, and where at least in some of their regions, T. confluens or T. bahiensis can be found at present. The possible reasons of this new distribution, as well as the possible causes for the occurrence of severe envenomations in regions where these were not observed historically, are discussed. Based on the severe envenomations observed and on this new distribution map, emphasis is placed on the need to capacitate health personnel in general and intensivists or critical care physicians in particular to adequately treat scorpion accidents.

Scorpion toxins targeting Kv1 3 channels: insights into immunosuppression

Scorpion venoms are natural sources of molecules that have, in addition to their toxic function, potential therapeutic applications. In this source the neurotoxins can be found especially those that act on potassium channels. Potassium channels are responsible for maintaining the membrane potential in the excitable cells, especially the voltage-dependent potassium channels (Kv), including Kv1.3 channels. These channels (Kv1.3) are expressed by various types of tissues and cells, being part of several physiological processes. However, the major studies of Kv1.3 are performed on T cells due its importance on autoimmune diseases. Scorpion toxins capable of acting on potassium channels (KTx), mainly on Kv1.3 channels, have gained a prominent role for their possible ability to control inflammatory autoimmune diseases. Some of these toxins have already left bench trials and are being evaluated in clinical trials, presenting great therapeutic potential. Thus, scorpion toxins are important natural molecules that should not be overlooked in the treatment of autoimmune and other diseases.(AU)

The evolution and distribution of noxious species of scorpions (Arachnida: Scorpiones)

This contribution attempts to bring some general information on the evolution and, in particular, on the geographic distribution of scorpion species noxious to humans. Since 95% of the scorpions incidents are generated by specimens of the family Buthidae C. L. Koch, the analysis will be limited to this familial group. As in previous similar contributions, the content of this work is mostly addressed to non-specialists whose research embraces scorpions in several fields such as venom toxins and public health. Only in recent years, efforts have been made to create better links between 'academic scorpion experts' and other academic non-specialists who use scorpions in their research. Even if a larger progress can yet be expected from such exchanges, crossed information proved to be useful in most fields of scorpion studies. Since the taxonomy of scorpions is complex, misidentifications and even more serious errors concerning scorpion classification/ identification are often present in the general literature. Consequently, a precise knowledge of the distribution patterns presented by many scorpion groups and, in particular, those of infamous species, proves to be a key point in the interpretation of final results, leading to a better treatment of the problems caused by infamous scorpion species.(AU)

Scorpionism by Hemiscorpius spp. in Iran: a review

Scorpions are distributed throughout Iran and the genus Hemiscorpius is particularly important in this region. Hemiscorpius lepturus is the most significant species within the genus in the country. Since scorpionism provoked by Hemiscorpius comprises a medical emergency, the present study is focused on this important issue. In order to perform the present work, a review of the medical and health-related literature was carried out in several databases. The current findings indicate that six species of Hemiscorpius are found in 15 states of Iran, mainly in the south and southwest. Deaths caused by stings were reported only for two species. The morphological characteristics and geographical distribution of H. lepturus in Iran, its venom and the toxic compounds, epidemiologic data and clinical manifestations of envenomation as well as treatment for affected people are herein reviewed and described. H. lepturus venom toxicity differs from other Iranian scorpions regarding duration and severity. Scorpionism is an important public health problem in Iran, especially in southwest and south regions and in urban areas. It is more prevalent in children and young people. H. lepturus venom is primarily a cytotoxic agent and has hemolytic, nephrotoxic and to some extent hepatotoxic activity. The use of polyvalent antivenom to prevent scorpion sting symptoms is recommended. A well-planned health education program might be useful in preventing scorpionism.(AU)

Mass fingerprinting and electrophysiological analysis of the venom from the scorpion Centruroides hirsutipalpus (Scorpiones: Buthidae)

Centruroides hirsutipalpus, of the family Buthidae, is a scorpion endemic to the Western Pacific region of Mexico. Although medically important, its venom has not yet been studied. Therefore, this communication aims to identify their venom components and possible functions. Methods Fingerprinting mass analysis of the soluble venom from this scorpion was achieved by high-performance liquid chromatography and electrospray mass spectrometry. Furthermore, the soluble venom and its toxic effects were evaluated extensively via electrophysiological assays in HEK cells expressing human voltage-gated Na+ channels (hNav 1.1 to Nav1.6), CHO cells expressing hNav 1.7, potassium channel hERG 1 (Ether-à-go-go-related-gene) and the human K+-channel hKv1.1. Results The separation of soluble venom produced 60 fractions from which 83 distinct components were identified. The molecular mass distribution of these components varies from 340 to 21,120 Da. Most of the peptides have a molecular weight between 7001 and 8000 Da (46% components), a range that usually corresponds to peptides known to affect Na+ channels. Peptides with molecular masses from 3000 to 5000 Da (28% of the components) were identified within the range corresponding to K+-channel blocking toxins. Two peptides were obtained in pure format and completely sequenced: one with 29 amino acids, showing sequence similarity to an "orphan peptide" of C. limpidus, and the other with 65 amino acid residues shown to be an arthropod toxin (lethal to crustaceans and toxic to crickets). The electrophysiological results of the whole soluble venom show a beta type modification of the currents of channels Nav1.1, Nav1.2 and Nav1.6. The main effect observed in channels hERG and hKv 1.1 was a reduction of the currents. Conclusion The venom contains more than 83 distinct components, among which are peptides that affect the function of human Na+-channels and K+-channels. Two new complete amino acid sequences were determined: one an arthropod toxin, the other a peptide of unknown function.(AU)

Effects of Brazilian scorpion venoms on the central nervous system

In Brazil, the scorpion species responsible for most severe incidents belong to the Tityus genus and, among this group, T. serrulatus, T. bahiensis, T. stigmurus and T. obscurus are the most dangerous ones. Other species such as T. metuendus, T. silvestres, T. brazilae, T. confluens, T. costatus, T. fasciolatus and T. neglectus are also found in the country, but the incidence and severity of accidents caused by them are lower. The main effects caused by scorpion venoms - such as myocardial damage, cardiac arrhythmias, pulmonary edema and shock - are mainly due to the release of mediators from the autonomic nervous system. On the other hand, some evidence show the participation of the central nervous system and inflammatory response in the process. The participation of the central nervous system in envenoming has always been questioned. Some authors claim that the central effects would be a consequence of peripheral stimulation and would be the result, not the cause, of the envenoming process. Because, they say, at least in adult individuals, the venom would be unable to cross the blood-brain barrier. In contrast, there is some evidence showing the direct participation of the central nervous system in the envenoming process. This review summarizes the major findings on the effects of Brazilian scorpion venoms on the central nervous system, both clinically and experimentally. Most of the studies have been performed with T. serrulatus and T. bahiensis. Little information is available regarding the other Brazilian Tityus species.(AU)

Purificación parcial de péptidos presentes en el veneno del escorpión Tityus macrochirus (Buthidae) y evaluación preliminar de su actividad citotóxica / Partial purification of peptides present in the Tityus macrochirus (Buthidae) scorpion venom and preliminary assessment of their cytotoxicity

RESUMEN Introducción. El veneno del escorpión posee péptidos con actividad neurotóxica que actúan principalmente en los canales iónicos del sistema nervioso de insectos y mamíferos. También se ha establecido su acción citolítica y anticancerígena, características biológicas que aún no se han explorado en el veneno del escorpión Tityus macrochirus. Objetivo. Evaluar si tanto el veneno total de T. macrochirus como la fracción de péptidos parcialmente purificados disminuyen el porcentaje de viabilidad de diferentes líneas celulares provenientes de tumores. Materiales y métodos. Mediante métodos cromatográficos, electroforéticos y de ultrafiltración con membranas de Amicon Ultra 0.5®, se identificaron y purificaron parcialmente los péptidos del veneno de T. macrochirus obtenido mediante estimulación eléctrica. Los ensayos de actividad citotóxica del veneno y de la fracción de péptidos se hicieron en líneas celulares provenientes de tumores con el método colorimétrico de reducción de la sal de tetrazolio (Mossman's Tetrazole Test, MTT). Resultados. El veneno de T. macrochirus posee péptidos con pesos moleculares entre 3 y 10 kDa, los cuales se purificaron parcialmente mediante ultrafiltración y se evaluaron mediante cromatografía líquida de alta resolución en fase inversa (Reverse Phase-High Pressure Liquid Chromatography, RP-HPLC). Los ensayos de citotoxicidad del veneno total de T. macrochirus evidenciaron una mayor disminución de la viabilidad en la línea celular PC3 que en las demás líneas celulares evaluadas, en tanto que la fracción parcialmente purificada de péptidos logró disminuir la viabilidad de la línea celular HeLa. Conclusión. Los péptidos del veneno de T. macrochirus presentaron actividad citotóxica en algunas de las líneas celulares provenientes de tumores, y se observó algún grado de selectividad frente a ellas.

ABSTRACT Introduction: Scorpion venom contains peptides with neurotoxic action primarily active on ion channels in the nervous system of insects and mammals. They are also characterized as cytolytic and anticancer, biological characteristics that have not yet been reported for the Tityus macrochirus venom. Objective: To assess if the total T. macrochirus venom and the fraction of partially purified peptides decrease the viability of various tumor-derived cell lines. Materials and methods: The scorpion venom was collected by electrical stimulation and, subsequently, subjected to chromatography, electrophoresis, and ultrafiltration with Amicon Ultra 0.5® membranes for the partial identification and purification of its peptides. The cytotoxic activity of the venom and the peptides fraction trials on tumor-derived cell lines were carried out by the MTT method. Results: The T. macrochirus scorpion venom has peptides with molecular weights ranging between 3 and 10 kDa. They were partially purified using the ultrafiltration technique, and assessed by the RP-HPLC method. Cytotoxicity trials with the whole T. macrochirus venom showed a higher viability decrease on the PC3 cell line compared to the other cell lines assessed, while the partially purified peptides decreased the HeLa cell line viability. Conclusion: Peptides in the T. macrochirus scorpion venom showed cytotoxic activity on some tumor-derived cell lines. We observed some degree of selectivity against other cell lines assessed.

Cardiorespiratory alterations in rodents experimentally envenomed with Hadruroides lunatus scorpion venom

Abstract Background Hadruroides lunatus is the most abundant scorpion species in the Peruvian central coast, where most of the accidents involving humans are registered. In spite of its prevalence, there are only very few studies on H. lunatus envenomation. The aim of the present study was to analyze the cardiorespiratory alterations caused by H. lunatus envenomation in rodents. Methods Wistar rats injected with H. lunatus scorpion venom were submitted to electrocardiography. After euthanasia, rat lungs were collected and histopathologically analyzed. Mouse cardiomyocytes were used to perform immunofluorescence and calcium transient assays. Data were analyzed by ANOVA or Student’s t-test. The significance level was set at p< 0.05. Results It was observed that H. lunatus venom increased heart rate and caused arrhythmia, thereby impairing the heart functioning. Lungs of envenomed animals showed significant alterations, such as diffuse hemorrhage. In addition, immunofluorescence showed that H. lunatus venom was capable of binding to cardiomyocytes. Furthermore, mouse ventricular cardiomyocytes incubated with H. lunatus venom showed a significant decrease in calcium transient, confirming that H. lunatus venom exerts a toxic effect on heart. Conclusion Our results showed that H. lunatus venom is capable of inducing cardiorespiratory alterations, a typical systemic effect of scorpionism, stressing the importance of medical monitoring in envenomation cases.

Partial purification and functional characterization of Ts19 Frag-I, a novel toxin from Tityus serrulatus scorpion venom

Background The yellow scorpion Tityus serrulatus (Ts) is responsible for the highest number of accidents and the most severe scorpion envenoming in Brazil. Although its venom has been studied since the 1950s, it presents a number of orphan peptides that have not been studied so far. The objective of our research was to isolate and identify the components present in the fractions VIIIA and VIIIB of Ts venom, in order to search for a novel toxin. The major isolated toxins were further investigated for macrophage modulation. Methods The fractions VIIIA and VIIIB, obtained from Ts venom cation exchange chromatography, were rechromatographed on a C18 column (4.6 × 250 mm) followed by a reversed-phase chromatography using another C18 column (2.1 × 250 mm). The main eluted peaks were analyzed by MALDI-TOF and Edmans degradation and tested on macrophages. Results The previously described toxins Ts2, Ts3-KS, Ts4, Ts8, Ts8 propeptide, Ts19 Frag-II and the novel peptide Ts19 Frag-I were isolated from the fractions VIIIA and VIIIB. Ts19 Frag-I, presenting 58 amino acid residues, a mass of 6,575 Da and a theoretical pI of 8.57, shares high sequence identity with potassium channel toxins (KTx). The toxins Ts4, Ts3-KS and the partially purified Ts19 Frag-I did not produce cytotoxic effects on macrophage murine cells line (J774.1). On the other hand, Ts19 Frag-I induced the release of nitric oxide (NO) by macrophages, while Ts4 and Ts3-KS did not affect the NO production at the tested concentration (50 g/mL). At the same concentration, Ts19 Frag-I and Ts3-KS increased the production of interleukin-6 (IL-6). Ts19 Frag-I and Ts4 did not induce the release of IL-10, IL-1 or tumor necrosis factor- by macrophage cells using the tested concentration (50 g/mL). Conclusions We partially purified and determined the complete sequence and chemical/physical parameters of a new -KTx, denominated Ts19 Frag-I. The toxins Ts4, Ts3-KS and Ts19 Frag-I showed no cytotoxicity toward macrophages and induced IL-6 release. Ts19 Frag-I also induced the release of NO, suggesting a pro-inflammatory activity.

Comparison between two methods of scorpion venom milking in Morocco

Background The present study compared two methods used successfully in a large-scale program for the collection of scorpion venoms, namely the milking of adult scorpions via manual and electrical stimulation. Results Our immunobiochemical characterizations clearly demonstrate that regularly applied electrical stimulation obtains scorpion venom more easily and, most importantly, in greater quantity. Qualitatively, the electrically collected venom showed lack of hemolymph contaminants such as hemocyanin. In contrast, manual obtainment of venom subjects scorpions to maximal trauma, leading to hemocyanin secretion. Our study highlighted the importance of reducing scorpion trauma during venom milking. Conclusions In conclusion, to produce high quality antivenom with specific antibodies, it is necessary to collect venom by the gentler electrical stimulation method.(AU)

Participação de fatores de crescimento e de citosinas nas alterações observadas na prole de ratas tratadas com o veneno do escorpião Tityus Bahiensis no período gestacional / Participation of growth factors and citokynes in alterations observed in offspring of rats treated with Tityus bahiensis scorpion venom during the pregnancy

No Brasil, o escorpionismo é um problema de saúde pública. O escorpião T. serrulatus é considerado o mais perigoso, mas um grande número de acidentes também acontece com o T. bahiensis. O objetivo do estudo foi verificar possíveis efeitos do veneno do escorpião T. bahiensis no desempenho reprodutivo materno e nos níveis de citocinas e fatores de crescimento em embriões de mães tratadas durante a gestação. Para os parâmetros reprodutivos foram utilizadas fêmeas prenhes injetadas com uma dose de 2,5mg/Kg (s.c.) do veneno no 5º (GD5) ou no 10º (GD10) dia gestacional. O grupo controle foi injetado com salina a 1,46% (1ml/Kg) em ambos os dias. No 21º dia gestacional, os filhotes foram retirados por laparotomia e divididos em dois grupos que receberam tratamento específico para a análise visceral e esquelética. Para avaliação dos níveis de citocinas e de fatores de crescimento, as fêmeas prenhes foram injetadas com salina (1ml/Kg), LPS (100μg/kg) ou veneno (2,5mg/Kg) no 10º (GD10) ou 16º (GD16) dia gestacional. Os filhotes foram removidos por laparotomia 6, 12 ou 24 horas após o tratamento materno. As amostras foram maceradas em um homogenizador de tecido e centrifugadas. Os níveis de citocinas e fatores de crescimento foram determinados por ensaios imunoenzimáticos. Nos parâmetros reprodutivos não houve alterações no peso materno durante a gestação, no número de corpos lúteos, número de filhotes, peso do útero e dos filhotes. Houve diminuição no número de implantações e reabsorções no grupo GD5. Houve aumento no peso das placentas em GD5 e GD10. No desenvolvimento dos filhotes foram observadas aumento no peso do coração e pulmão em GD5 e GD10 e no peso do fígado em GD10. Não foram observadas anomalias e malformações internas ou externas nos filhotes de ambos os grupos experimentais. Em GD10 não foram observadas alterações nos níveis de citocinas 6 horas após a aplicação do veneno, mas verificou-se diminuição do nível de INF-γ 24 horas depois...

In Brazil scorpionism is a public health problem. The scorpion T. serrulatus is considered the most dangerous, but a large number of accidents also occur with T. bahiensis. The objective of this work was to verify the possible effects of the T. bahiensis scorpion venom on the maternal reproductive parameters and on the cytokines levels and growth factors in embryos after the treatment of pregnancy females. To the reproductive parameters it was used pregnant females injected with a dose of 2.5mg/Kg (s.c.) of the venom. The experimental groups were injected with venom on the 5th (GD5) or on the 10th (GD10) gestational day. The control group was injected with NaCl 1.46% on both days. On the 21st gestational day, the pups were taken out by laparotomy and were divided into two groups that received specific treatments for skeletal or visceral analyses. To evaluate the cytokines levels, pregnant females were injected with saline (1ml/kg), LPS (100μg/kg) or crude venom (2.5mg/kg) on the 10th (GD10) or 16th (GD16) gestational day. The pups were removed by laparotomy 6, 12 or 24 hours after the mother’s treatment. The samples (embryo/placenta) were macerated by a tissue homogenizer and centrifuged. The cytokine levels were determined by enzyme immunoassays. In the reproductive parameters no changes were observed in the maternal weight during the gestational period, corpora lutea, number of pups, uterus weight and pups weight. There was a decrease on the number of implantation and resorption in GD5 There was alteration on the placenta’s weight in GD5 and GD10. In pups development there were observed alterations in the heart and lung weight on GD5 and GD10 and on the liver weight on GD10. There were not observed external or internal anomalies and malformations in the offspring of both experimental groups. The cytokines levels were not alterated after 6 hours in GD10. In GD16 there was an increase in the IL-1α levels...

Scorpion sting-induced myocardial damage and pulmonary oedema.

A patient with electrocardiographic abnormalities simulating early myocardial infarction after scorpion sting is reported. Pulmonary oedema and congestive heart failure accompanied these electrocardiographic changes. The aetiology of the cardiovascular manifestations in severe scorpion sting is related to the venom effects on the sympathetic nervous system and the adrenal secretion of catecholamines, as well as to the toxic effects of the venom on the myocardium.

Efeitos da Toxina TsTX-I isolada do veneno do Escorpião Tityus serrulatus sobre o hipocampo de ratos / Effects of TsTX-I toxin isolated from Tityus serrulatus scorpion venom on the hippocampus of rats

Os venenos escorpiônicos são compostos, entre outras substâncias , por neurotoxinas, polipeptídios básicos de baixo peso molecular que atuam sobre canais iônicos alterando a liberação de mediadoes químicos. O veneno do escorpião Tityus serrulatus tem sido extensamente estudado e muitas de suas toxinas já foram bem caracterizadas e sequenciadas. Entre as mais importantes se encontra a TsTX-I, uma toxina que se liga ao sítio 4 do canal de sódio, que já foi bem estudada quanto a seus periféricos, embora seus efeitos centrais sejam pouco conhecidos...

Scorpion venoms are composed mainly neurotoxins that are basic peptides with low molecular weight acting on ionic channels, mainly sodium channel, changing the release of chemical mediators. Crude venom of Tityus serrulatus scorpion as well its toxins, has already been extensively studied. Many of the venom toxins were well characterized and sequenced. TsTX- I is one of the most important toxin present in the the venom. This toxin actin by binding on site 4 of sodium channel, its peripherical effects have been well studied but its central effects are not well kmow...

Scorpion bite induced myocardial damage and pulmonary edema

A patient with electrocardiographic abnormalities after scorpion sting, simulating early myocardial infarction, is reported here. Pulmonary edema and congestive heart failure accompanied these electrocardiographic changes. The etiology of the cardiovascular manifestations in severe scorpion sting is related to the venom effects on the sympathetic nervous system and the adrenal secretion of catecholamines as well as to the toxic effects of the venom on the myocardium

Envenenamiento de Chelydra serpentina (Reptilia: Testudines) por Tityus trivittatus (Scorpionida: Buthidae) / Envenomation of Chelydra serpentina (Reptilia: Testudines) by Tityus trivittatus (Scorpionida: Buthidae)

Se describe el caso de un ejemplar de tortuga mordedora (Chelydra serpentina) que fue hallada con los miembros tetanizados en extensión, midriasis y poca respuesta a estímulos externos, en cuyo recinto se encontró un ejemplar de escorpión Tityus trivittatus. Ante el claro cuadro de envenenamiento, se trató al quelonio con antiveneno escorpiónico específico retornando a un estado de relajación muscular a las seis horas y encontrándoselo totalmente normal a las 24 horas sin mostrar secuelas posteriores. Este es el primer comunicado sobre el envenenamiento de quelonios por escorpiones. Se discuten algunos aspectos de este envenenamiento escorpiónico y su tratamiento con antiveneno específico.

We report the case of a snapping turtle (Chelydra serpentina) found tetanized, with the limbs in extension, mydriasis and poor response to external stimuli, in whose terrarium was found a Tityus trivittatus scorpion. Based on the clear clinical picture of envenoming, the turtle was treated with a specific scorpion antivenin, returning to a state of muscle relaxation after six hours of treatment and it was found totally normal at 24 hours, without envenoming sequelae. This is the first report on turtle envenomation by scorpion. The scorpion envenomation in reptiles and the treatment with specific antivenom is discussed.

Experimental Tityus serrulatus scorpion envenomation: age- and sex-related differences in symptoms and mortality in mice

Among the various methods for evaluating animal venom toxicity, the calculation of the median lethal dose (LD50) is the most widely used. Although different protocols can be used to calculate the LD50, the source of the venom and the method of extraction, as well as the strain, age, and sex of the animal model employed, should be taken into consideration. The objective of the present study was to evaluate the influence of sex and age on the toxicity of Tityus serrulatus scorpion venom in Swiss mice. Although the symptoms of envenomation were similar in male and female animals, female mice proved to be more resistant to the venom. In females, age had no impact on the susceptibility to scorpion envenomation. Male mice were more sensitive to T. serrulatus venom. Moreover, in males, age was an important parameter since sensitivity to the venom increased with age.

Neurotransmitter evaluation in the hippocampus of rats after intracerebral injection of TsTX scorpion toxin

TsTX is an á-type sodium channel toxin that stimulates the discharge of neurotransmitters from neurons. In the present study we investigated which neurotransmitters are released in the hippocampus after TsTX injection and if they are responsible for electrographic or histopathological effects. Microdialysis revealed that the toxin increased glutamate extracellular levels in the hippocampus; however, levels of gamma-aminobutyric acid (GABA), glycine, 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were not significantly altered. Neurodegeneration in pyramidal cells of hippocampus and electroencephalographic alterations caused by the toxin were blocked by pretreatment with riluzole, a glutamate release inhibitor. The present results suggest a specific activity of TsTX in the hippocampus which affects only glutamate release.