Portal de Pesquisa da BVS Veterinária

Tese em Português | VETTESES | ID: vtt-213971

Resumo

A urolitiase e enfermidade com importancia economica para a ovinocultura, que causa a saida prematura de ovinos machos destinados a reproducao, custos com tratamento e morte. A associacao entre avaliacao hemogasometrica, pesquisa de proteinas de fase aguda (PFA) como biomarcadores precoces e o estudo morfometrico do trato urinario pode ser empregada como método de auxilio diagnostico precoce para a doenca. Com esse objetivo, foram utilizados 14 ovinos higidos, machos (nao castrados), da raca Santa Ines com idade aproximada de 90 dias. Os ovinos receberam dieta experimental hiperfosforica durante todo o periodo experimental, foram examinados semanalmente e apos desenvolvimento da urolitiase, reorganizados em dois grupos experimentais distintos D1 (sem urolitiase) e D2 (com urolitiase) para analise comparada dos dados. No periodo pre-experimental e no dia do abate foram coletadas amostras de sangue venoso para avaliação hemogasometrica. Para mensurar as imunoglobulinas (A e G) e as PFA, analisaramse as amostras dos ovinos que desenvolveram a urolitiase (D2). As coletas de sangue foram realizadas semanalmente ate a manifestacao clinica da enfermidade, totalizando 16 amostras. Ao termino do experimento foi realizado o abate e necropsia dos ovinos, para descricao das alteracoes patologicas e a analise morfometrica. Fragmentos do trato urinario e figado foram coletados e submetidos a rotina histologica e as laminas histologicas foram descritas, seguindo-se a histomorfometria. Embora o pH sanguineo nao tenha sido diferente (P < 0,05) entre grupos, os ovinos que desenvolveram urolitiase apresentaram alcalose metabolica compensatoria. Elevacao da pressao parcial de dioxido de carbono (pCO2) foi observada entre D1 e D2, mas houve diferenca (P < 0,05) apenas nos momentos finais (MFs). Expressivas diferencas de excesso de base (EB), dioxido de carbono total no plasma (tCO2), bicarbonato (HCO3-) e saturacao de bicarbonato (stHCO3-), foram registradas apenas nos MFs, assim como maiores valores para Na+ e K+. As PFA que apresentaram diferenca (P < 0,05) ao longo do tempo foram haptoglobina e transferrina. Necrose do processo uretral e bexiga urinaria repleta foram observados em todos ovinos que desenvolveram urolitiase. Alem disso, um dos ovinos apresentou hidronefrose, extensa area de hemorragia na bexiga urinaria, alem de ruptura de uretra e edema subcutaneo. Nao houve diferenca significativa nas variaveis morfometricas macroscopicas entre grupos, com excecao da largura do ureter direito, contrariando a hipotese de sua possivel utilizacao como metodo de auxilio diagnostico precoce para a urolitiase. Quanto a avaliacao histopatologica, foram observadas areas multifocais de discreta a moderada congestao dos tufos glomerulares e proteina no lumen tubular dos rins. No figado, observou-se nas regioes centrolobulares, discreta a moderada degeneracao gordurosa e apenas em um ovino foi observada, macro e microscopicamente, area focal ulcerada na mucosa da bexiga. Os achados da presente pesquisa demonstraram que a dieta formulada foi eficaz na inducao da doenca clinica. Foram encontradas lesoes no figado e trato urinario, mas nao houve alteracoes histomorfometricas significativas.

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Urolithiasis is an economically important disease for male sheep production that causes the premature calving of sheep for breeding, treatment costs and death. The association between hemogasometric evaluation, acute phase protein (APP) research as early biomarkers and urinary tract morphometric study can be employed as an early diagnostic aid for the disease. For this purpose, 14 healthy male (non-castrated) Santa Ines sheep, approximately 90 days old, were used. Sheep received a hyperphosphoric experimental diet throughout the experimental period, were examined weekly and after development of urolithiasis, reorganized into two distinct experimental groups D1 (without urolithiasis) and D2 (with urolithiasis) for comparative analysis of the data. In the pre-experimental period and on the day of slaughter, venous blood samples were collected for hemogasometric evaluation. To measure immunoglobulins (A and G) and APP, samples from sheep that developed urolithiasis (D2) were analyzed. Blood samples were collected weekly until the clinical manifestation of the disease, totaling 16 samples. At the end of the experiment, sheep were slaughtered and necropsied to describe the pathological changes and the morphometric analysis. Urinary tract and liver fragments were collected and submitted to histological routine and histological slides were described, followed by histomorphometry. Although blood pH was not different (P < 0.05) between groups, sheep that developed urolithiasis had compensatory metabolic alkalosis. Carbon dioxide partial pressure elevation (pCO2) was observed between D1 and D2, but there was a difference (P < 0.05) only in the final moments (FMs). Significant differences in base excess (BE), total plasma carbon dioxide (tCO2), bicarbonate (HCO3-) and bicarbonate saturation (stHCO3-) were recorded only in the FMs, as well as higher values for Na+ and K+. The APP that showed difference (P < 0.05) over time were haptoglobin and transferrin. Necrosis of the urethral process and full urinary bladder were observed in all sheep that developed urolithiasis. In addition, one of the sheep presented hydronephrosis, extensive area of urinary bladder hemorrhage, urethral rupture and subcutaneous edema. There was no significant difference in macroscopic morphometric variables between groups, except for right ureter width, contrary to the hypothesis of its possible use as an early diagnostic aid method for urolithiasis. Regarding histopathological evaluation, multifocal areas of mild to moderate congestion of the glomerular tufts and protein in the tubular lumen in the kidneys were observed. In the liver, in the centrilobular regions, mild to moderate fatty degeneration was observed, and only in one sheep was observed, macroscopically and microscopically, an ulcerated focal area in the bladder mucosa. The findings of the present research demonstrated that the formulated diet was effective in inducing clinical disease. Liver and urinary tract lesions were found, but there were no significant histomorphometric changes.

Biblioteca responsável: BR68.1