Resultado da pesquisa (5)
Termo utilizado na pesquisa Pseudocalymma elegans
#1 - Antagonism of acetamid in experiments with sheep, goats and rabbits indicates that monofluoroacetate is the toxic principle of Pseudocalymma elegans Bignoniaceae, 31(10):867-874
Abstract in English:
ABSTRACT.- Helayel M.A., Caldas S.A., Peixoto T.C., França, T.N., Tokarnia C.H., Döbereiner J., Nogueira V.A. & Peixoto P.V. 2011. [Antagonism of acetamid in experiments with sheep, goats and rabbits indicates that monofluoroacetate is the toxic principle of Pseudocalymma elegans Bignoniaceae.] O antagonismo com acetamida em experimentos com ovinos, caprinos e coelhos indica monofluoroacetato como princípio tóxico de Pseudocalymma elegans Bignoniaceae. Pesquisa Veterinária Brasileira 31(10):867-874. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: michel_abdallavet@yahoo.com.br
This study aimed to evaluate the protective effect of acetamid in experimental poisoning by Pseudocalymma elegans in sheep, goats and rabbits, in order to prove indirectly that monofluoroacetate (MF) is responsible for the clinical signs and death of animals that ingested the plant. Experiments were performed to determine for sheep and goats the lethal dose of P. elegans collected in Rio Bonito, RJ, in different seasons, and to adjust the dose of acetamid to be administered. - In the first experiment, two sheep and two goats received 1.0g/kg of fresh P. elegans, and two (one sheep and one goat) were pretreated with 2.0g/kg of acetamid. None of the animals showed clinical signs or died. Possibly, the plant could be less toxic, since it was collected at the end of the rainy season. - In the second experiment, two sheep and two goats received 0.67 and 1.0g/kg of the dried plant, after pretreatment with 2.0 and 3.0g/kg of acetamid, respectively. All animals died, as the administered doses of P. elegans were very high. - In the third experiment, two sheep and two goats received 0.333g/kg of dried P. elegans after previous administration of 2.0g/kg of acetamid; a week later, the protocol above was repeated, but without the antidote. In experiments with rabbits, doses of 0.5 and 1.0g/kg of dried P. elegans were given after administration of 3.0g/kg of acetamid; seven days later, the same protocol was repeated, except the administration of acetamide. This procedure, when acetamid was administered before, prevented the appearance of clinical signs and death of sheep, goats and rabbits. But the animals not treated with acetamid showed symptoms of poisoning and died. Clinically, the sheep and goats had tachycardia, engorged jugular vein, positive venous pulse, lateral recumbence, and muscle tremors. In the “dramatic phase”, the animals fell into lateral position, stretched the limbs, were paddling and died within minutes. The rabbits showed apathy, muscle tremors, vocalization and lateral decumbence minutes before death. At postmortem examination, the sheep and goats had engorged jugular veins and atria, dilated vena cava cranialis and caudalis, as well as pulmonary edema, hepatic congestion and edema of the gallbladder subserosa. In rabbits, the main macroscopic alterations were dilated atria, engorged vena cava cranialis and caudalis, and congested liver and diaphragm vessels. Histopathology revealed, in two sheep and one goat, vacuolar-hydropic degeneration of the distal convoluted kidney tubules, together with caryopicnosis. In the rabbits, the liver showed severe congestion with numerous shock corpuscles. The experimental results show indirectly that MF is to be held responsible for death of the animals that ingested P. elegans; since “acetate donor” compounds, such as acetamid, are capable to reduce the competitive inhibition of MF for the same active site (Coenzyme A) which prevents the formation of fluorocitrate, its active metabolite, formed in the body through the so-called “lethal synthesis”.
Abstract in Portuguese:
RESUMO.- Helayel M.A., Caldas S.A., Peixoto T.C., França, T.N., Tokarnia C.H., Döbereiner J., Nogueira V.A. & Peixoto P.V. 2011. [Antagonism of acetamid in experiments with sheep, goats and rabbits indicates that monofluoroacetate is the toxic principle of Pseudocalymma elegans Bignoniaceae.] O antagonismo com acetamida em experimentos com ovinos, caprinos e coelhos indica monofluoroacetato como princípio tóxico de Pseudocalymma elegans Bignoniaceae. Pesquisa Veterinária Brasileira 31(10):867-874. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: michel_abdallavet@yahoo.com.br
#2 - Morte súbita em bovinos causada pela ingestão de Pseudocalymma elegans (Bignoniaceae) no município de Rio Bonito, RJ, p.498-508
Abstract in English:
ABSTRACT.- Helayel M.A., França T.N., Seixas J.N., Nogueira V.A., Caldas S.A. & Peixoto P.V. 2009. [Sudden death in cattle caused by ingestion of Pseudocalymma elegans (Bignoniaceae) in the county of Rio Bonito, Rio de Janeiro.] Morte súbita em bovinos causada pela ingestão de Pseudocalymma elegans (Bignoniaceae) no município de Rio Bonito, RJ. Pesquisa Veterinária Brasileira 29(7):498-508. Curso de Pós-Graduação em Medicina Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: michel_abdallavet@yahoo.com.br
Natural poisoning by Pseudocalymma elegans, a plant that causes “sudden death” and only occurs in the State of Rio de Janeiro, is described in a cow. This condition was experimentally reproduced in three calves and three rabbits with the plant collected in the area where the deaths had occurred. Postmortem and histopathological examinations of the natural case in the cow did not reveal significant alterations. Oral administration of 1g/kg of the sprouts of P. elegans caused death of the calf 5 hours and 30 minutes after beginning of the administration. The dose of 0.5 g/kg caused death of another calf with onset of symptoms after 3 hours and 24 minutes and a course of 73 hours and 12 minutes. Animals that ingest borderline doses may show a longer course with a characteristic clinical picture of heart impairment. The dose of 0.25g/kg did not cause death, but only clinical signs. Heart palpitation and arrhythmia, increase of breathing frequency, reluctance in moving, positive venous pulse, ingurgitated jugular veins, falling down and peddling movements shortly before death, were observed. At postmortem examination the lesions were those of acute heart insufficiency, and histopathological examination revealed the typical kidney lesion (hydropic-vacular degeneration in the distal convoluted tubules) seen in poisoning by plants that cause “sudden death”. In the experimentally poisoned rabbits the clinical course was less than 1-2 minutes. In the kidney of two rabbits there was also the characteristic microscopic lesion. The presence of the plant in the county of Rio Bonito had not been known by the veterinarians. It is concluded that the plant could be more toxic than described before.
Abstract in Portuguese:
RESUMO.- Helayel M.A., França T.N., Seixas J.N., Nogueira V.A., Caldas S.A. & Peixoto P.V. 2009. [Sudden death in cattle caused by ingestion of Pseudocalymma elegans (Bignoniaceae) in the county of Rio Bonito, Rio de Janeiro.] Morte súbita em bovinos causada pela ingestão de Pseudocalymma elegans (Bignoniaceae) no município de Rio Bonito, RJ. Pesquisa Veterinária Brasileira 29(7):498-508. Curso de Pós-Graduação em Medicina Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: michel_abdallavet@yahoo.com.br
Descreve-se a intoxicação natural por Pseudocalymma elegans em pelo menos um bovino em Rio Bonito, RJ e a reprodução experimental dessa intoxicação em três bovinos e em 3 coelhos com exemplares dessa planta colhida no local onde ocorreu a morte. Necropsia e histopatologia do bovino naturalmente intoxicado não revelaram alterações significativas. A administração, por via oral, de 1g/kg da brotação da planta causou a morte do bovino dentro de 5h e 30 minutos após o início da administração, já pela administração de 0,5 g/kg, a morte do animal ocorreu após 76 horas e 36 minutos. A dose de 0,25g/kg foi capaz de causar sintomas, mas não levou a morte. A sintomatologia caracterizou-se por arritmia cardíaca, taquicardia, aumento da freqüência respiratória, relutância em se mover, pulso venoso positivo, jugulares e grandes vasos ingurgitados, queda ao solo e movimentos de pedalagem, seguindo-se o óbito. À necropsia foram verificadas alterações compatíveis com às observadas na insuficiência cardíaca aguda, e o exame histopatológico revelou a lesão renal típica (degeneração hidrópica em túbulos contornados distais) de intoxicação por plantas que causam “morte súbita”. Nos coelhos, a evolução variou entre menos de um minuto a dois minutos. O exame histopatológico do rim de dois coelhos também revelou a lesão microscópica característica. Essa planta ainda não havia sido mapeada nessa área do Estado do Rio de Janeiro. Conclui-se que a planta pode ser mais tóxica do que anteriormente descrito.
#3 - Experimental poisoning in horses by Pseudocalymma elegans (Bignoniaceae)
Abstract in English:
Pseudocalymma elegans (Vell.) Kuhlm., a plant poisonous to cattle in the State of Rio de Janeiro, also has been implicated, from time to time, as the cause death in horses. ln arder to establish its toxicity to this animal species and the clinical-pathological picture, sprouts of the plant were given orally to 8 horses in doses ranging from 0.8 to 3.2 g/kg. The lethal dose found was 2.4 g/kg. The symptoms of poisoning by P. elegans in the horse were characterized mainly by nervous manifestations such as intense sweating, abrupt involuntary movements of the head or the whole body, ílacid lips, somnolence, instability and falling down of the animal; less evidente were signs of cardiac insufficiency shown by positive venous pulse, dyspnoea and laborious respiration. The first symptoms were seen between 9h15mln and 27h after the start of feeding the plant, and the clinical course of the poisoning varied from 5h08min to 21h11min. The clinical signs of poisoning by P. elegans were similar to those caused by Palicourea marcgravii in horses, but different from those observed in cattle where poisoning by both plants is characterized by "sudden death" due to an acute cardiac insufficiency. Also contrary to the poisoning in cattle, exercise had no influence on the manifestation of symptoms. As in cattle, there were very few post-morten findings. The most important histological lesion was, necrosis of the epithelial cells of the uriniferous tubules with picnosis of their nuclei and vacuolization of the cytoplasffi; frequently resulting in lysis. This lesion was more marked than that observed in cattle, but unlike that caused by P. marcgravii, in the poisoning of horses by P. elegans it was seen mainly in the distal convoluted uriniferous tu bules.
Abstract in Portuguese:
Pseudocalymma elegans (Vell.) Kuhlm., planta tóxica de interesse pecuário para bovinos no Estado do Rio de Janeiro, é suspeita de também ser responsável pela morte de eqüinos. Para estabelecer a sensibilidade dos eqüinos a P. elegans e determinar o. quadro clínico-patológico, a brotação da planta foi administrada, por via oral, a oito eqüinos, em doses de 0,8 a 3,2 g/ kg. A dose letal situou-se em 2,4 g/kg. O quadro clínico da intoxicação por P. elegans em eqüinos se relacionava sobretudo ao sistema nervoso central e era representado por sudorese, movimentos abruptos involuntários da cabeça ou afetando todo corpo (tiques), lábio inferior flácido, sonolência, relutância em locomover-se, instabilidade com queda, tremores musculares, movimentos de mastigação vazios, ranger de dentes; sinais de insuficiência cardíaca, como pulso venoso positivo, dispnéia, respiração ofegante, eram menos evidentes. Os primeiros sintomas após o início da administração da planta foram observados entre 9h15min e 27h e a evolução da intoxicação nos casos fatais variou entre 5h08min e 21h11min. Os achados de necropsia foram praticamente negativos. As alterações histológicas mais importantes e constantes foram necrose das células epiteliais dos túbulos uriníferos, caracterizada por picnose nuclear e vacuolização citoplasmática com freqüente evolução paralise.
#4 - Experimental poisoning of sheep by Pseudocalymma elegans (Bignoniaceae)
Abstract in English:
The fresh leaves of Pseudocalymma elegans (Vell.) Kuhlm., a poisonous liane for cattle, were also toxic for sheep when administered orally. The lethal dose was 1,5 grams of the fresh plant per kilogram of body weight. The dried plant was also toxic, but the lethal dose was 1 g/kg, corresponding to 3 g/kg of the fresh plant. In experiments where sheep were given repeated daily doses of 1/5, 1/10 and 1/20 of the lethal dose of dried leaves of P. elegans, a pronounced cumulative toxic effect was noted with daily quantities of 1/5, a moderate cumulative toxic effect with daily doses of 1/10, and only a slight one with daily doses of 1/20 of the lethal dose. The subsequent administration of a single lethal dose to surviving sheep of these experiments showed that the plant did not induce tolerance or immunity to the toxic properties of the plant. P. elegans caused the clinical and pathological symptoms of "sudden death", that is, a poisoning of peracute course, which lasted from a few minutes up to 24 minutes in one case. Symptoms and death of the sheep could be caused or precipitated by exercise. In experiments with both single and repeated administrations of fractions of the lethal dose, a few sheep exibited short lasting symptoms of poisoning during exercise prior to death. The symptoms of poisoning of sheep by P. elegans were, in order of appearance: reluctance to walk, dyspnea, tachycardia, difficulty in remaining standing, generalized muscular tremors, sometimes the animal laid down or fell to the ground, opisthotonus, generalized contractions and death. Post-mortem examination only revealed pulmonary edema in sheep fed repeated fractions of the lethal dose. This occurred in 5 of the 8 sheep which died in these experiments. Histological studies revealed alterations mainly in liver, kidney, heart and lungs. The nature of these changes were circulatory, regressive, inflammatory and proliferative in the heart, circulatory and regressive in the kidney, regressive in the liver and circulatory in the lungs. Changes in the kidney and liver showed no difference in nature or incidence between sheep receiving the plant once or repeatedly. But heart lesions, mainly those of proliferative nature, and changes in the lungs, were seen principally in the sheep from experiments with repeated administrations of fractions of the lethal dose.
Abstract in Portuguese:
As folhas de Pseudocalymma elegans (Vell.) Kuhlm., planta tóxica para bovinos, também se revelaram tóxicas para ovinos, quando administradas experimentalmente por via oral, tanto em estado fresco como dessecado. A dose letal da planta fresca foi 1,5 g/kg. A dose letal da planta dessecada foi 1g/kg, que corresponde a 3 g/kg da planta fresca. Administrações diárias de frações da dose letal demonstraram que, para ovinos, a planta dessecada tem acentuado efeito acumulativo nas dosagens de 1/5 da dose letal, moderado nas de 1/10 da dose letal e somente leve nas de 1/20 da dose letal; entretanto a planta não induz tolerância ou imunidade. Nos ovinos a planta provocou o quadro clínico-patológico da "morte súbita", isto é, uma intoxicação de evolução superaguda, com duração de minutos, no máximo de 24 minutos. Os sintomas e a morte dos animais puderam ser provocados ou precipitados pelo exercício. Tanto nos experimentos de administrações únicas como nos de administrações repetidas de frações da dose letal, alguns animais mostraram sintomas em exercícios anteriores àquele que culminou com a morte. Os sintomas observados foram, na seqüência em que apareceram, relutância em correr, dispnéia, taquicardia, dificuldade de ficar em pé, tremores musculares generalizados, às vezes o animal se deitava, às vezes caía ao chão, opistotono, contrações generalizadas e morte. Achados de necropsia consistentes foram verificados somente em 5 dos 8 ovinos que receberam administrações repetidas de frações da dose letal, sob forma de edema pulmonar. Histologicamente observaram-se, no coração, alterações de natureza circulatória, regressiva, inflamatória e proliferativa, no rim de natureza circulatória e regressiva, no fígado de natureza regressiva e no pulmão de natureza circulatória. As alterações renais e hepáticas mantiveram uniformidade em natureza e incidência, porém as alterações cardíacas, sobretudo as de natureza proliferativa, e as pulmonares, foram encontradas principalmente nos ovinos nos experimentos de administrações repetidas de frações da dose letal.
#5 - Experimental poisoning of goats by Pseudocalymma elegans (Bignoniaceae)
Abstract in English:
The sprouts of Pseudocalymma elegans (Vell.) Kuhlm., a liane known to be toxic to cattle in the State of Rio de Janeiro, were found to be toxic also for goats. The smallest dose of the plant administered orally, which caused death of all goats, was 1 g/kg (5 animals). One out of 4 goats died when fed 0.75 g/kg and one of 5 goats given 0.5 g/kg. The experiments suggest that young animals are more sensitive. AH but one animal that showed symptoms of poisoning, died. Both symptoms and death occurred in most goats when exercised. The course of the poisoning varied from 6 minutes to 3 days. The symptoms of poisoning by P. elegans in goats were reluctance to walk, sternal decubitus, dispnea, frequent bleating, muscular tremors, lateral decubitus and death. Exercise was found to always aggravate symptoms. Post-mortem examinations revealed no significant lesions. Histopathological studies generally showed lesions in heart, liver and kidney. Necrosis of heart fibers were seen in the myocardium of 2 goats, accompanied by macrophages and in one case by fibroblasts. Vacuolization was seen in most livers. ln the kidney hydropic-vacuolar degeneration of the epithelial cells of the proximal convoluted tubules was seen in 3 cases and coagulative necrosis of the tubules in the cortex of one case.
Abstract in Portuguese:
Foi confirmada também para caprinos a toxidez da brotação de Pseudocalymma elegans (Vell.) Kuhlm., planta tóxica de interesse pecuário para bovinos no Estado do Rio de Janeiro. A menor dose da brotação fresca, administrada por via oral, que causou a morte de todos os caprinos, foi 1 g/kg (5 animais). Ainda morreram um de 4 caprinos que tinham ingerido 0,75 g/kg e um de 5 caprinos que tinham recebido 0,5 g/kg. Os experimentos sugerem que animais jovens são mais sensíveis a essa intoxicação. Todos os animais que mostraram sintomas, com exceção de um, morreram. Os sintomas de intoxicação e a morte dos caprinos apareceram, na grande maioria dos casos. Após exercício a que os animais experimentais eram submetidos 2 vezes ao dia, a partir de aproximadamente 15 horas após a ingestão da planta. Além disto, o exercício, toda vez que era aplicado, também acentuava a sintomatologia, uma vez manifestada. A evolução clínica da intoxicação por P. elegans em caprinos variou de 6 minutos a 3 dias. Os sintomas observados foram relutância em andar, decúbito esterno-abdominal, dispnéia, freqüentes balidos, tremores musculares, ducúbito lateral e morte. Não foram verificados achados de necropsia significantes. Os exames histopatológicos revelaram alterações no coração, fígado e rim. No miocárdio observaram-se áreas de necrose de coagulação em 2 dos 8 caprinos mortos, com presença de macrófagos, e em um adicionalmente com presença de fibroblastos. No fígado observou-se, na maioria dos casos, vacuolização de hepatócitos. No rim foi observada degeneração hidrópico-vacuolar das células·epiteliais dos túbulos contornados distais em 3 animais, e necrose de coagulação tubular no córtex de um.
