Decreased expression of cardie troponin C is associated with cardiac lesions in amorinia exotropica poisoned cattle.

Abstract

The plants which cause sudden death of cattle in Brazil occupy a leading position for losses in the cattle industry. Amorimia exotropica is one of the plants pertaining to this group. Diagnostic indings in these cases may be inconclusive; further knowledge is necessary. This paper identi ies cardiac lesions through anti-cardiac troponin C (cTnC) immunehistochemistry performed in tissues from cattle poisoned after consumption of A. exotropica in southern Brazil. Heart fragments from nine A. exotropica-poisoned cattle were studied immunohistochemically using anti-human cTnC as the primary antibody. In the hearts from all of the poisoned cattle, there was a sharp decrease in the cTnC expression level in the cytoplasm of groups of cardiomyocytes. A signi icant decrease in anti-cTnC immunoreactivity occurred particularly in degenerated or necrotic cardiomyocytes. Occasional groups of cells showed complete loss of immunolabeling. In the remaining intact cardiomyocytes from poisoned cattle and in cardiomyocytes from six cattle that died from other causes there was intense cytoplasmic staining.

No Brasil, plantas cujo consumo determina morte súbita de bovinos estão entre as principais causas de perdas na pecuária. Esse trabalho identi ica lesões cardíacas através de imuno-histoquímica antitroponina cardíaca C (TncC), desenvolvida em tecidos de bovinos intoxicados após consumo de Amorimia exotropica, no sul do Brasil. Fragmentos cardíacos de nove bovinos intoxicados, naturalmente, por Amorimia exotropica foram examinados por imuno-histoquímica anti-TncC, como anticorpo primário. Nos corações de todos os bovinos intoxicados pela planta, havia pronunciada diminuição dos níveis de expressão de TncC no citoplasma de grupos de cardiomiócitos. Diminuição signi icativa na imunorreatividade anti-TncC ocorreu, particularmente, em cardiomiócitos degenerados ou necróticos. Grupos ocasionais de células mostraram completa perda de imunomarcação. Em cardiomiócitos remanescentes e intactos de bovinos intoxicados e em cardiomiócitos de seis bovinos que morreram por outras causas, observou-se intensa coloração citoplasmática.