Identificação e distribuição de lesões cardíacas em bovinos intoxicados por Amorimia exotropica

Abstract

Amorimia exotropica is a shrub of the Malpighiacea family that contains sodium monofluoroacetate as the toxic principle, which has a cardiotoxic action in cattle. In Southern Brazil it is the only species of the group of plants that causes "sudden death during exercise". This study has identified and mapped cardiac lesions observed in cattle naturally poisoned by A. exotropica. An outbreak of poisoning by the plant occurred in a beef cattle herd in Rio Grande do Sul, where nine bovine hearts were selected for examination and mapping of eight distinct topographical regions (apex, right and left ventricles, interventricular septum, right and left papillary muscles , right and left atrium). At gross examination, four cattle showed focal and well-defined lesions in the left papillary muscle. This corresponds to areas of coagulation necrosis in different stages of evolution on histology, similar to infarcts. All hearts showed cardiomyocytes necrosis, characterized by shrinkage and hypereosinophilic cytoplasm and cellular fragmentation in all sampled areas. The severity of cellular injury was evaluated by immunohistochemistry anti-troponin C, which showed marked decrease of cytoplasm staining in necrotic cells. The left papillary muscle was the most affected region in cases of poisoning by A. exotropica.

Clinical-pathological and immunohistochemical evaluations of cardiac lesions in cats with chronic kidney disease

“…On macroscopic examination, several organs were evaluated in detail, and the data were recorded in forms prepared for this research. At necropsy, the hearts were collected whole for gross evaluation according to the technique described by Bandinelli et al (2014). Then they were cross-sectioned in a total of four complete sections equidistant from each other.…”

“…Several immunohistochemical techniques with high specificity and sensitivity have been developed aiming to detect damage to the cardiomyocytes. Among these, cardiac troponin has shown promising results in cattle (Ortmann et al 2000, Pavarini et al 2012, Bandinelli et al 2014, sheep (Costa et al 2016), anddogs (D'avila et al 2016). Necrotic cardiomyocytes, detectable or not by routine optical microscopy exams, show negative immunostaining, while those unaffected are positive for troponin (Jenkins et al 2010, Bandinelli et al 2014Costa et al 2016.…”

Plantas cardiotóxicas para ruminantes no Brasil

“…Amorimia exotropica ocorre em locais sombreados na mata atlântica do Sudeste (São Paulo) e Sul (Paraná, Rio Grande do Sul e Santa Catarina). O primeiro surto de intoxicação em bovinos foi descrito no Estado de Santa Catarina (Gava et al 1998) e mais recentemente nas regiões metropolitanas de Porto Alegre, Serra Gaúcha e microrregião de Vacaria, Rio Grande do Sul (Pavarini et al 2011, Bandinelli et al 2014. As intoxicações ocorrem durante todo o ano, porém, com maior concentração de casos entre os meses de maio e agosto, período em que há escassez de alimentos no Sul do Brasil.…”

“…(Medeiros et al 2002). Em alguns casos, como nas intoxicações por A. exotropica, A. amazonica e A. septentrionalis, a evolução pode ser subaguda e, dessa forma, o coração pode exibir aspecto globular com áreas esbranquiçadas no miocárdio, além de áreas focais vermelhas entremeadas por áreas brancacentas na musculatura papilar esquerda (Soares et al 2011, Bandinelli et al 2014. Sendo assim, pode haver necrose de coagulação com infiltrado inflamatório composto por macrófagos, linfócitos, neutrófilos degenerados, além de tecido conjuntivo (fibrose) e debris celulares (Bandinelli et al 2014.…”

Ultrastructural lesions in the myocardium and kidneys of rabbits in experimental acute Amorimia exotropica poisoning

“…septentrionalis (Lee et al 2002). Another plant of this genus, A. exotropica, is incriminated in poisoning with sudden death in ruminants in Northern Rio Grande do Sul State , Bandinelli et al 2014.When poisoned by these plants, cattle die after a rapidly progressive clinical disease triggered by exercise; however, animals may die without showing any clinical signs. Muscular tremors, staggering gait, dyspnea, jugular engorgement, opisthotonus, recumbency, and paddling are immediately followed by death (Tokarnia et al 2012).…”