Resumo O presente trabalho tem por objetivo descrever, pela primeira vez no Estado do Tocantins, as características epidemiológicas, clínicas e patológicas de um surto de intoxicação espontânea por Combretum glaucocarpa em bovinos. De um lote de 200 bovinos acessíveis à planta, 70 animais chegaram a óbito. Os sinais observados foram edema na região posterior da coxa e inguinal, períneo, escroto e ventre do abdômen, tórax e barbela; fezes escuras e fétidas; emagrecimento e pêlos ásperos. O curso clínico variou de 3 a 20 dias. As concentrações séricas de ureia e creatinina e as atividades séricas de alanino-aminotransferase e aspartato-aminotransferase estavam elevadas nos dez animais avaliados. As lesões observadas foram grande quantidade de transudato na cavidade abdominal, tórax e saco pericárdico. Notou-se edema na bexiga, tecidos perirenais e na subserosa da vesícula biliar, junto à sua inserção com o fígado. Este estava aumentado, com bordos arredondados, congesto e azulado. Petéquias e equimoses foram observadas no epicárdio, miocárdio, mucosa da traqueia, omento, serosa do rúmen, vesícula urinária e testículos. Áreas de sufusões foram observadas no encéfalo. Na histopatologia, visualizou-se degeneração hidrópica centrolobular leve no fígado e, no rim, focos de hemorragia na junção corticomedular com degeneração tubular leve. Encontraram-se células epiteliais necróticas e cilindros hialinos em alguns túbulos renais. É a primeira descrição por C. glaucocarpum em bovinos no Tocantins.

Abstract The present study aimed to describe, for the first time in Tocantins State, the epidemiological, clinical, and pathological aspects of an outbreak of Combretum glaucocarpa poisoning in cattle. From a herd of 200 cattle that had access to the plant, 70 animals died. The signs were swelling of the posterior thigh, groin, perineum, scrotum, ventral abdomen, chest, and barb; dark and fetid stools; marked weight loss, and rough hair. The clinical course ranged from 3 to 20 days. The serum activities of alanine aminotransferase and aspartate amininotransferase and the serum concentrations of urea and creatinine were markedly elevated in all the ten animals examined. The gross lesions consisted of large amouts of transudate in the peritoneal, pleural, and pericardial cavities. Edema was also seen in the urinary bladder, perirenal tissue and gallbladder subserosa at its insertion to the liver. The liver was enlarged, congested, and bluish. Petechiae and ecchymosis were observed in the epicardium, myocardium, tracheal mucosa, omentum, ruminal serosa, urinary bladder, and testicles. Suffusions were detected in the brain. Histopathology of the liver revealed mild centrilobular degeneration. In the kidney, hemorrhagic foci in corticomedullary junction with mild tubular degeneration were observed. Additionally, some renal tubules had necrotic epithelial cells and hyaline casts. It is the first report of poisoning by C. glaucocarpum in cattle in Tocantins.

Este estudo teve como objetivo avaliar o efeito do acetato de medroxi-progesterona (MAP) com ou sem benzoato de estradiol (BE) sobre o crescimento folicular durante o ciclo estral bovino. No primeiro experimento, vacas da raça Hereford foram sincronizadas com um análogo sintético de PGF2á e tratadas com duas doses diferentes de MAP (250 ou 500mg), com ou sem EB, durante 7 dias, iniciando-se no oitavo dia do ciclo estral. Observou-se uma inibição do crescimento folicular (P<0,05) em todas as vacas, exceto no grupo controle e no grupo que recebeu 250mg de MAP sem BE. Os 75% dos animais não exibiu estro no momento da remoção do MAP, mas sim nos dias 21 e 22 do ciclo, demonstrando que os tratamentos não induziram cio. Para se determinar se o tratamento com BE alterou a sensibilidade endometrial à ocitocina e, assim, a cascata luteolítica, vacas multíparas pré-sincronizadas receberam 5mg de BE, seguidos, após 6 horas, de 50 UI de ocitocina (OT; n=9). Oito horas após a administração de BE, colheram-se fragmentos endometriais das vacas, nos dias 4, 13 e 17 do ciclo estral, mensurando-se a expressão gênica de COX-2 através de PCR. O BE aumentou os níveis de RNAm de COX-2 apenas no dia 17 do ciclo estral (P<0,05). Em conclusão, o MAP isolado ou associado a BE é capaz de suprimir o crescimento folicular bovino. Entretanto, o BE, na presença de MAP é ineficaz na indução da luteólise bovina, quando injetado no oitavo dia do ciclo estral.

The objective of this study was to evaluate the effect of medroxy-progesterone acetate (MAP) with or without estradiol benzoate (EB) on follicular growth during the estrous cycle in cattle. In the first experiment, Hereford cows were synchronized with a synthetic analogue of PGF2 alpha and were treated with two different doses of MAP (250 or 500 mg) with or without EB for 7 days starting on day 8 of the estrous cycle. Follicular growth was inhibited (P<0.05) in all cows except controls and those receiving 250mg MAP without EB. Seventy-five percent of the animals (15/20) showed estrus on days 21 and 22 of the cycle rather than at MAP withdrawal, demonstrating that these treatments did not induce estrus. To determine whether the EB treatment altered endometrial sensitivity to oxytocin and thus the luteolytic cascade, multiparous pre-synchronized cows received 5 mg of EB followed 6 hours later with 50 IU of oxytocin (OT; n=9). Eight hours after EB injection, endometrial fragments were collected from the cows on days 4, 13 and 17 of the estrous cycle and COX-2 gene expression was measured by PCR. EB increased COX-2 mRNA levels only on day 17 of the estrous cycle (P<0.05). In conclusion, MAP alone or associated with EB is able to suppress bovine follicular growth. However, EB in the presence of MAP is not efficient to induce luteolysis in cows when injected on day 8 of the estrous cycle.

Matrix metalloproteinases (MMP) are key enzymes involved in tissue remodeling. Within the ovary, they are believed to play a major role in ovulation, and have been linked to follicle atresia. To gain insight into the regulation of MMPs, we measured the effect of hormones and growth factors on MMP2 and MMP9 mRNA levels in non-luteinizing granulosa cells in serum-free culture. FSH and IGF1 both stimulated estradiol secretion and inhibited MMP2 and MMP9 mRNA abundance. In contrast, EGF and FGF2 both inhibited estradiol secretion but had no effect on MMP expression. At physiological doses, none of these hormones altered the proportion of dead cells. Although we cannot link MMP expression with apoptosis, the specific down regulation by the gonadotropic hormones FSH and IGF1 in vitro suggests that excess MMP2 and MMP9 expression is neither required nor desired for follicle development.