RESUMO

Portulaca species can switch between C4 and crassulacean acid metabolism (CAM) depending on environmental conditions. However, the regulatory mechanisms behind this rare photosynthetic adaptation remain elusive. Using Portulaca oleracea as a model system, here we investigated the involvement of the circadian clock, plant hormones, and transcription factors in coordinating C4 and CAM gene expression. Free-running experiments in constant conditions suggested that C4 and CAM gene expression are intrinsically connected to the circadian clock. Detailed time-course, drought, and rewatering experiments revealed distinct time frames for CAM induction and reversion (days versus hours, respectively), which were accompanied by changes in abscisic acid (ABA) and cytokinin metabolism and signaling. Exogenous ABA and cytokinins were shown to promote and repress CAM expression in P. oleracea, respectively. Moreover, the drought-induced decline in C4 transcript levels was completely recovered upon cytokinin treatment. The ABA-regulated transcription factor genes HB7, NFYA7, NFYC9, TT8, and ARR12 were identified as likely candidate regulators of CAM induction following this approach, whereas NFYC4 and ARR9 were connected to C4 expression patterns. Therefore, we provide insights into the signaling events controlling C4-CAM transitions in response to water availability and over the day/night cycle, highlighting candidate genes for future functional studies in the context of facultative C4-CAM photosynthesis.

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RESUMO

The Portulacaceae enable the study of the evolutionary relationship between C4 and crassulacean acid metabolism (CAM) photosynthesis. Shoots of well-watered plants of the C3-C4 intermediate species Portulaca cryptopetala Speg. exhibit net uptake of CO2 solely during the light. CO2 fixation is primarily via the C3 pathway as indicated by a strong stimulation of CO2 uptake when shoots were provided with air containing 2% O2. When plants were subjected to water stress, daytime CO2 uptake was reduced and CAM-type net CO2 uptake in the dark occurred. This was accompanied by nocturnal accumulation of acid in both leaves and stems, also a defining characteristic of CAM. Following rewatering, net CO2 uptake in the dark ceased in shoots, as did nocturnal acidification of the leaves and stems. With this unequivocal demonstration of stress-related reversible, i.e. facultative, induction of CAM, P. cryptopetala becomes the first C3-C4 intermediate species reported to exhibit CAM. Portulaca molokiniensis Hobdy, a C4 species, also exhibited CAM only when subjected to water stress. Facultative CAM has now been demonstrated in all investigated species of Portulaca, which are well sampled from across the phylogeny. This strongly suggests that in Portulaca, a lineage in which species engage predominately in C4 photosynthesis, facultative CAM is ancestral to C4. In a broader context, it has now been demonstrated that CAM can co-exist in leaves that exhibit any of the other types of photosynthesis known in terrestrial plants: C3, C4 and C3-C4 intermediate.

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Three outbreaks of poisoning by Portulaca oleracea were reported in sheep and goats in Northeast Brazil. In the first outbreak, 8 out of 20 sheep were affected and later died. In the second outbreak, three goats and one sheep died out of a flock of 30 animals that included both species. In the third outbreak, two out of 19 sheep were affected, and they recovered after a treatment of 2% methylene blue at a dose of 4 mg/kg body weight. In the first and second outbreaks, the animals ingested P. oleracea after it was cut and offered in feeders. In the third outbreak, the flock was grazing in an area that had been invaded by the plant. To determine the toxicity, P. oleracea was administered experimentally at a dose of 80g/kg of body weight to seven sheep, weighing 19-30 kg. One control sheep received green grass. One to four hours after P. oleracea ingestion, the animals showed clinical signs of poisoning characterized by cyanotic mucous membranes, bloat, ruminal pH of 8-9, pollakiuria, aerophagia, involuntary movements of the upper lip, apathy, tachypnea and tachycardia. Five animals recovered, including one that was treated with 1% methylene blue, and two animals died. During necropsy, the mucous membranes were brownish, and the blood was dark brown. Diphenylamine tests of the plant and of rumen contents were positive for nitrates. Positive results for nitrates were also found in 24 samples of P. oleracea that were collected in different places in the states of Pernambuco and Paraíba. We conclude that P. oleracea accumulates nitrates at toxic levels and may cause poisoning in sheep and goats.(AU)

Relatam-se três surtos de intoxicação por Portulaca oleracea em ovinos e caprinos no Nordeste do Brasil. No primeiro surto morreram oito de 20 ovinos. No segundo morreram três caprinos e um ovino de um total de 30 animais das duas espécies. No terceiro surto foram afetadas duas ovelhas de um rebanho de 19 animais, que se recuperaram após o tratamento com azul de metileno a 2% na dose de 4 mg/kg/vivo. Nos surtos 1 e 2 os animais ingeriram P. oleracea cortada e oferecida no coxo e no surto 3 estavam pastoreando em uma área invadida pela planta. Para determinar a toxicidade de P. oleracea foram utilizados oitos ovinos, sendo sete experimentais e um controle, com peso entre 19 e 30 kg. A planta foi administrada por via oral, na dose de 80 g/kg/peso corporal. O animal controle recebeu capim verde e concentrado. Entre uma a quatro horas após a ingestão da planta os animais apresentaram sinais clínicos caracterizados por mucosas cianóticas, timpanismo gasoso, pH ruminal de 8-9, polaquiúria, aerofagia, movimentos involuntários do lábio superior, apatia, taquipnéia e taquicardia. Cinco animais se recuperaram, incluindo um que foi tratado com azul de metileno a 2%, e dois morreram. Na necropsia observaram-se mucosas de coloração marrom e sangue marrom escuro. O teste de difenilamina realizado na planta e no conteúdo ruminal foi positivo para nitratos. Resultados positivos para nitratos foram detectados em 24 amostras coletadas em diferentes locais dos estados de Pernambuco e Paraíba. Conclui-se que P. oleracea acumula nitratos em níveis tóxicos, e quando ingerida por ovinos e caprinos pode provocar intoxicação e morte.(AU)

Assuntos

RESUMO

Three outbreaks of poisoning by Portulaca oleracea were reported in sheep and goats in Northeast Brazil. In the first outbreak, 8 out of 20 sheep were affected and later died. In the second outbreak, three goats and one sheep died out of a flock of 30 animals that included both species. In the third outbreak, two out of 19 sheep were affected, and they recovered after a treatment of 2% methylene blue at a dose of 4 mg/kg body weight. In the first and second outbreaks, the animals ingested P. oleracea after it was cut and offered in feeders. In the third outbreak, the flock was grazing in an area that had been invaded by the plant. To determine the toxicity, P. oleracea was administered experimentally at a dose of 80g/kg of body weight to seven sheep, weighing 19-30 kg. One control sheep received green grass. One to four hours after P. oleracea ingestion, the animals showed clinical signs of poisoning characterized by cyanotic mucous membranes, bloat, ruminal pH of 8-9, pollakiuria, aerophagia, involuntary movements of the upper lip, apathy, tachypnea and tachycardia. Five animals recovered, including one that was treated with 1% methylene blue, and two animals died. During necropsy, the mucous membranes were brownish, and the blood was dark brown. Diphenylamine tests of the plant and of rumen contents were positive for nitrates. Positive results for nitrates were also found in 24 samples of P. oleracea that were collected in different places in the states of Pernambuco and Paraíba. We conclude that P. oleracea accumulates nitrates at toxic levels and may cause poisoning in sheep and goats.(AU)

Relatam-se três surtos de intoxicação por Portulaca oleracea em ovinos e caprinos no Nordeste do Brasil. No primeiro surto morreram oito de 20 ovinos. No segundo morreram três caprinos e um ovino de um total de 30 animais das duas espécies. No terceiro surto foram afetadas duas ovelhas de um rebanho de 19 animais, que se recuperaram após o tratamento com azul de metileno a 2% na dose de 4 mg/kg/vivo. Nos surtos 1 e 2 os animais ingeriram P. oleracea cortada e oferecida no coxo e no surto 3 estavam pastoreando em uma área invadida pela planta. Para determinar a toxicidade de P. oleracea foram utilizados oitos ovinos, sendo sete experimentais e um controle, com peso entre 19 e 30 kg. A planta foi administrada por via oral, na dose de 80 g/kg/peso corporal. O animal controle recebeu capim verde e concentrado. Entre uma a quatro horas após a ingestão da planta os animais apresentaram sinais clínicos caracterizados por mucosas cianóticas, timpanismo gasoso, pH ruminal de 8-9, polaquiúria, aerofagia, movimentos involuntários do lábio superior, apatia, taquipnéia e taquicardia. Cinco animais se recuperaram, incluindo um que foi tratado com azul de metileno a 2%, e dois morreram. Na necropsia observaram-se mucosas de coloração marrom e sangue marrom escuro. O teste de difenilamina realizado na planta e no conteúdo ruminal foi positivo para nitratos. Resultados positivos para nitratos foram detectados em 24 amostras coletadas em diferentes locais dos estados de Pernambuco e Paraíba. Conclui-se que P. oleracea acumula nitratos em níveis tóxicos, e quando ingerida por ovinos e caprinos pode provocar intoxicação e morte.(AU)

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RESUMO

Descreve-se um surto de intoxicação aguda em bovinos causado pela ingestão de Portulaca elatior na região nordeste do Brasil. O surto resultou da ingestão a partir da administração da planta no cocho pelo criador para os bovinos. Quatro de cinco bovinos foram intoxicados e dois morreram. Os sinais clínicos incluíram dor abdominal, tremores musculares, intensa salivação, timpanismo moderado e desidratação. O curso clínico da doença variou de 10 a 18 horas. Os achados macroscópicos incluíram desidratação, avermelhamento das mucosas dos pré-estômagos, abomaso e intestinos, além de ulceração da mucosa ruminal. Nos dois casos foi notada a presença de fragmentos de Portulaca no interior do rúmen. Os achados histológicos foram de degeneração e necrose das camadas superficiais do epitélio dos pré-estômagos, necrose e inflamação da mucosa intestinal e necrose linfoide. As atividades de AST e GGT estavam dentro dos valores de normalidade. O diagnóstico de intoxicação associado à ingestão de P. elatior foi baseado na epidemiologia, sinais clínicos e lesões. A ausência de informação sobre a toxicidade de P. elatior foi a principal causa para a ocorrência da intoxicação acidental.(AU)

An outbreak of acute poisoning in cattle caused by the ingestion of Portulaca elatior occurred in the northeastern Brazil. The outbreak resulted from ingestion of the plant provided by the farmer. Four out of five cattle were poisoned and two died. Clinical signs included abdominal pain, muscle trembling, intense salivation, mild bloat and dehydration. The course of the disease ranged from 10 to 18 hours. Gross findings included dehydration, reddening of the mucosa of forestomachs, abomasum, and intestine, with ulcerations of the ruminal mucosa. The presence of Portulaca leaves in the rumen was noted in both cases. The main histologic lesions were superficial to full thickness degeneration and necrosis of the stratified epithelium lining the forestomachs, necrosis and inflammation of the intestinal mucosa, and lymphoid necrosis. The serum activities of AST and GGT and serum were within normal ranges. The diagnosis of poisoning associated with ingestion of P. elatior was based on the epidemiology, clinical signs and lesions. The lack of information about the toxicity of P. elatior was the main cause for the accident of poisoning.(AU)

Assuntos

RESUMO

Descreve-se um surto de intoxicação aguda em bovinos causado pela ingestão de Portulaca elatior na região nordeste do Brasil. O surto resultou da ingestão a partir da administração da planta no cocho pelo criador para os bovinos. Quatro de cinco bovinos foram intoxicados e dois morreram. Os sinais clínicos incluíram dor abdominal, tremores musculares, intensa salivação, timpanismo moderado e desidratação. O curso clínico da doença variou de 10 a 18 horas. Os achados macroscópicos incluíram desidratação, avermelhamento das mucosas dos pré-estômagos, abomaso e intestinos, além de ulceração da mucosa ruminal. Nos dois casos foi notada a presença de fragmentos de Portulaca no interior do rúmen. Os achados histológicos foram de degeneração e necrose das camadas superficiais do epitélio dos pré-estômagos, necrose e inflamação da mucosa intestinal e necrose linfoide. As atividades de AST e GGT estavam dentro dos valores de normalidade. O diagnóstico de intoxicação associado à ingestão de P. elatior foi baseado na epidemiologia, sinais clínicos e lesões. A ausência de informação sobre a toxicidade de P. elatior foi a principal causa para a ocorrência da intoxicação acidental.(AU)

An outbreak of acute poisoning in cattle caused by the ingestion of Portulaca elatior occurred in the northeastern Brazil. The outbreak resulted from ingestion of the plant provided by the farmer. Four out of five cattle were poisoned and two died. Clinical signs included abdominal pain, muscle trembling, intense salivation, mild bloat and dehydration. The course of the disease ranged from 10 to 18 hours. Gross findings included dehydration, reddening of the mucosa of forestomachs, abomasum, and intestine, with ulcerations of the ruminal mucosa. The presence of Portulaca leaves in the rumen was noted in both cases. The main histologic lesions were superficial to full thickness degeneration and necrosis of the stratified epithelium lining the forestomachs, necrosis and inflammation of the intestinal mucosa, and lymphoid necrosis. The serum activities of AST and GGT and serum were within normal ranges. The diagnosis of poisoning associated with ingestion of P. elatior was based on the epidemiology, clinical signs and lesions. The lack of information about the toxicity of P. elatior was the main cause for the accident of poisoning.(AU)

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RESUMO

ABSTRACT: An outbreak of acute poisoning in cattle caused by the ingestion of Portulaca elatior occurred in the northeastern Brazil. The outbreak resulted from ingestion of the plant provided by the farmer. Four out of five cattle were poisoned and two died. Clinical signs included abdominal pain, muscle trembling, intense salivation, mild bloat and dehydration. The course of the disease ranged from 10 to 18 hours. Gross findings included dehydration, reddening of the mucosa of forestomachs, abomasum, and intestine, with ulcerations of the ruminal mucosa. The presence of Portulaca leaves in the rumen was noted in both cases. The main histologic lesions were superficial to full thickness degeneration and necrosis of the stratified epithelium lining the forestomachs, necrosis and inflammation of the intestinal mucosa, and lymphoid necrosis. The serum activities of AST and GGT and serum were within normal ranges. The diagnosis of poisoning associated with ingestion of P. elatior was based on the epidemiology, clinical signs and lesions. The lack of information about the toxicity of P. elatior was the main cause for the accident of poisoning.

RESUMO: Descreve-se um surto de intoxicação aguda em bovinos causado pela ingestão de Portulaca elatior na região nordeste do Brasil. O surto resultou da ingestão a partir da administração da planta no cocho pelo criador para os bovinos. Quatro de cinco bovinos foram intoxicados e dois morreram. Os sinais clínicos incluíram dor abdominal, tremores musculares, intensa salivação, timpanismo moderado e desidratação. O curso clínico da doença variou de 10 a 18 horas. Os achados macroscópicos incluíram desidratação, avermelhamento das mucosas dos pré-estômagos, abomaso e intestinos, além de ulceração da mucosa ruminal. Nos dois casos foi notada a presença de fragmentos de Portulaca no interior do rúmen. Os achados histológicos foram de degeneração e necrose das camadas superficiais do epitélio dos pré-estômagos, necrose e inflamação da mucosa intestinal e necrose linfoide. As atividades de AST e GGT estavam dentro dos valores de normalidade. O diagnóstico de intoxicação associado à ingestão de P. elatior foi baseado na epidemiologia, sinais clínicos e lesões. A ausência de informação sobre a toxicidade de P. elatior foi a principal causa para a ocorrência da intoxicação acidental.

RESUMO

This first phytochemical study of Talinum triangulare Leach (Portulacaceae), also known as 'cariru', which is a commonly consumed food in Northern Brazil, allowed the isolation and structural determination of four new compounds: one acrylamide, 3-N-(acryloyl, N-pentadecanoyl) propanoic acid (5), and three new phaeophytins named (15(1)S, 17R, 18R)-Ficuschlorin D acid (3(1),3(2)-didehydro-7-oxo-17(3)-O-phytyl-rhodochlorin-15-acetic acid), (13), Talichorin A (17R, 18R)-phaeophytin b-15(1)-hidroxy, 15(2),15(3)-acetyl-13(1)-carboxilic acid (14), and (15(1)S, 17R, 18R)-phaeophytin b peroxylactone or (15(1)S, 17R, 18R)-hydroperoxy-ficuschlorin D (16), together with twelve known compounds, including four phaeophytins (11,12, 15 and 17). The structures of the compounds were established on the basis of 1D and 2D NMR, IR, HRESI-MS spectra, including GC-MS, and HPLC-UV analysis, as well as comparisons with the literature data. The CD spectra data analysis were used to define the absolute configuration of phaeophytins 12 (13(2)R, 17R, 18R)-13(2)-hydroxyphaeophytin a, 13 and 16, 15 (15(1)S, 17R, 18R)-3(1),3(2)-didehydro-15(1)-hydroxyrhodochlorin-15-acetic acid δ-lactone-15(2)-methyl-17(3)-phytyl ester and 17 (17R, 18R)-purpurin 18-phytyl ester.

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RESUMO

The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE) and the hydromethanolic fraction (Fraction 1), resulting in a concentration of 0.5853 g/100 g for Fraction 1, and 0.1400 g/100 g for the CE. Taking into account the results of the DPPH, the free radical scavenging capacity was confirmed. The formation of complexes with Fe II ions was evaluated by UV/visible spectrometry; results showed that CE has complexing power similar to the positive control (Gingko biloba extract).The inhibitory capacity of samples against the tyrosinase enzyme was determined by the oxidation of L-DOPA, providing IC50 values of 13.3 µg·mL(-1) (CE) and 6.6 µg·mL(-1) (Fraction 1). The values indicate that Fraction 1 was more active and showed a higher inhibitory power on the tyrosinase enzyme than the ascorbic acid, used as positive control. The hydromethanolic extract of T. triangulare proved to have powerful antioxidant activity and to inhibit the tyrosinase enzyme; its potential is increased after the partition with chloroform.

RESUMO

Um surto de intoxicação espontânea por Portulaca elatior foi diagnosticado no município de Aroeiras, Paraíba, na época das chuvas. Entre os meses de fevereiro e abril, em um rebanho de 316 caprinos, 16 adoeceram, sendo 15 de um lote de 16 caprinos que tinham sido introduzidos recentemente na fazenda e um animal do rebanho já existente na fazenda. Os caprinos apresentaram intensa salivação, relutância em se movimentar, tremores de lábios, marcha incoordenada, diarreia, timpanismo, dor abdominal, gemidos, desidratação e berros constantes. A evolução da enfermidade variou de 2 a 48 horas; 13 caprinos morreram e três se recuperaram. As lesões macroscópicas caracterizavam-se por mucosa ruminal e do retículo avermelhadas, serosa do rúmen hemorrágica, mucosa abomasal avermelhada com áreas ulceradas e mucosa do intestino delgado com equimoses. No exame histopatológico observou-se degeneração e necrose das células epiteliais dos pré-estômagos com formação de vesículas e infiltrado inflamatório neutrofílico. Suspeita de ter causado o surto, Portulaca elatior foi administrada a três caprinos nas doses de 40, 20 e 10 gramas de planta fresca por kg de peso animal (g/kg). Esses caprinos apresentaram sinais semelhantes aos casos espontâneos. Os animais que ingeriram 20 e 40g/kg morreram e o que ingeriu 10g/kg se recuperou. Microscopicamente foram observadas lesões do sistema digestivo semelhantes às dos casos espontâneos. A reprodução experimental da intoxicação, com sinais clínicos e lesões histológicas semelhantes às dos casos espontâneos, comprova que a doença foi causada por Portulaca elatior. P. elatior apresentou níveis de oxalatos de 6,37 por cento e outra planta, identificada como Blutaparon vermiculare e que ocorria em grande quantidade nas pastagens, apresentou níveis de oxalatos de 5,29 por cento. B. vermiculare foi administrada experimentalmente a um caprino na dose de 40g/kg, sem que o animal apresentasse sinais clínicos[...]

An outbreak of poisoning by Portulaca elatior was diagnosed in the state of Paraíba, northeastern Brazil, during the rainy season. Between February and April, 16 out of 316 goats were affected and 13 died. Fifteen of the affected animals were from a flock of 16 goats introduced on the farm at the beginning of the rainy season. Clinical signs were intense salivation, reluctance to move, lip tremors, slight uncoordinated gait, diarrhea, bloat, abdominal pain, groans, dehydration and constant bellowing. The course of the disease ranged from 2 to 48 hours; 13 goats died and three recovered. Gross lesions were reddening of the mucosa of rumen and reticulum, hemorrhages in the ruminal serosa, ulcerations of the abomasal mucosa, and ecchymoses in the small intestinal mucosa. Histological examination revealed degeneration and necrosis of epithelial cells with vesicle formation in the fore stomachs associated with infiltration by neutrophils. Suspected to have caused the outbreak, Portulaca elatior was administered experimentally to three animals at doses of 40, 20 and 10 grams of the fresh plant per kg bodyweight, respectively. The goats that ingested 20 and 40g/kg died, and the one that ingested 10g/kg showed clinical signs but recovered. These animals showed similar clinical signs and histological lesions as those seen in the goats poisoned spontaneously, demonstrating that the disease was caused by the ingestion of Portulaca elatior. Oxalate concentration were determined in P. elatior and in another plant identified as Blutaparon vermiculare. P. elatior contained 6.37 percent of total oxalates and B. vermiculare 5.29 percent. B. vermiculare was administered experimentally to one goat at a dose of 40g/kg, without causing clinical signs. These results and the absence of oxalate crystals in the digestive system and kidneys of the goats necropsied suggest that poisoning by P. elatior is not caused by high oxalate concentration in the plant.

Assuntos

RESUMO

Um surto de intoxicação espontânea por Portulaca elatior foi diagnosticado no município de Aroeiras, Paraíba, na época das chuvas. Entre os meses de fevereiro e abril, em um rebanho de 316 caprinos, 16 adoeceram, sendo 15 de um lote de 16 caprinos que tinham sido introduzidos recentemente na fazenda e um animal do rebanho já existente na fazenda. Os caprinos apresentaram intensa salivação, relutância em se movimentar, tremores de lábios, marcha incoordenada, diarreia, timpanismo, dor abdominal, gemidos, desidratação e berros constantes. A evolução da enfermidade variou de 2 a 48 horas; 13 caprinos morreram e três se recuperaram. As lesões macroscópicas caracterizavam-se por mucosa ruminal e do retículo avermelhadas, serosa do rúmen hemorrágica, mucosa abomasal avermelhada com áreas ulceradas e mucosa do intestino delgado com equimoses. No exame histopatológico observou-se degeneração e necrose das células epiteliais dos pré-estômagos com formação de vesículas e infiltrado inflamatório neutrofílico. Suspeita de ter causado o surto, Portulaca elatior foi administrada a três caprinos nas doses de 40, 20 e 10 gramas de planta fresca por kg de peso animal (g/kg). Esses caprinos apresentaram sinais semelhantes aos casos espontâneos. Os animais que ingeriram 20 e 40g/kg morreram e o que ingeriu 10g/kg se recuperou. Microscopicamente foram observadas lesões do sistema digestivo semelhantes às dos casos espontâneos. A reprodução experimental da intoxicação, com sinais clínicos e lesões histológicas semelhantes às dos casos espontâneos, comprova que a doença foi causada por Portulaca elatior. P. elatior apresentou níveis de oxalatos de 6,37 por cento e outra planta, identificada como Blutaparon vermiculare e que ocorria em grande quantidade nas pastagens, apresentou níveis de oxalatos de 5,29 por cento. B. vermiculare foi administrada experimentalmente a um caprino na dose de 40g/kg, sem que o animal apresentasse sinais clínicos[...](AU)

An outbreak of poisoning by Portulaca elatior was diagnosed in the state of Paraíba, northeastern Brazil, during the rainy season. Between February and April, 16 out of 316 goats were affected and 13 died. Fifteen of the affected animals were from a flock of 16 goats introduced on the farm at the beginning of the rainy season. Clinical signs were intense salivation, reluctance to move, lip tremors, slight uncoordinated gait, diarrhea, bloat, abdominal pain, groans, dehydration and constant bellowing. The course of the disease ranged from 2 to 48 hours; 13 goats died and three recovered. Gross lesions were reddening of the mucosa of rumen and reticulum, hemorrhages in the ruminal serosa, ulcerations of the abomasal mucosa, and ecchymoses in the small intestinal mucosa. Histological examination revealed degeneration and necrosis of epithelial cells with vesicle formation in the fore stomachs associated with infiltration by neutrophils. Suspected to have caused the outbreak, Portulaca elatior was administered experimentally to three animals at doses of 40, 20 and 10 grams of the fresh plant per kg bodyweight, respectively. The goats that ingested 20 and 40g/kg died, and the one that ingested 10g/kg showed clinical signs but recovered. These animals showed similar clinical signs and histological lesions as those seen in the goats poisoned spontaneously, demonstrating that the disease was caused by the ingestion of Portulaca elatior. Oxalate concentration were determined in P. elatior and in another plant identified as Blutaparon vermiculare. P. elatior contained 6.37 percent of total oxalates and B. vermiculare 5.29 percent. B. vermiculare was administered experimentally to one goat at a dose of 40g/kg, without causing clinical signs. These results and the absence of oxalate crystals in the digestive system and kidneys of the goats necropsied suggest that poisoning by P. elatior is not caused by high oxalate concentration in the plant.(AU)

Assuntos