Priscila Viau Furtado

LC-MS/MS quantitation of plasma progesterone in cattle

Quantitation of progesterone (P(4)) in biological fluids is often performed by radioimmunoassay (RIA), whereas liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been used much less often. Due to its autoconfirmatory nature, LC-MS/MS greatly minimizes false positives and interference. Herein we report and compare with RIA an optimized LC-MS/MS method for rapid, efficient, and cost-effective quantitation of P(4) in plasma of cattle with no sample derivatization. The quantitation of plasma P(4) released from three nonbiodegradable, commercial, intravaginal P(4)-releasing devices (IPRD) over 192 h in six ovariectomized cows was compared in a pairwise study as a test case. Both techniques showed similar P(4) kinetics (P > 0.05) whereas results of P(4) quantitation by RIA were consistently higher compared with LC-MS/MS (P < 0.05) due to interference and matrix effects. The LC-MS/MS method was validated according to the recommended analytical standards and displayed P(4) limits of detection (LOD) and quantitation (LOQ) of 0.08 and a 0.25 ng/mL, respectively. The high selective LC-MS/MS method proposed herein for P(4) quantitation eliminates the risks associated with radioactive handling; it also requires no sample derivatization, which is a common requirement for LC-MS/MS quantitation of steroid hormones. Its application to multisteroid assays is also viable, and it is envisaged that it may provide a gold standard technique for hormone quantitation in animal reproductive science studies.

Relação do grau de automutilação com as concentrações de metabólitos fecais de glicocorticoides em chimpanzés (Pan troglodytes)

A influencia do estresse de um ambiente nas variaveis endocrino-comportamentais de primatas vem sendo cada vez mais estudada por diversos autores, e mostram que comportamentos anormais associados a aumentos de glicocorticoides podem estar diretamente relacionados ao comprometimento do bem-estar. Neste trabalho foram utilizados 22 chimpanzes (Pan troglodytes) adultos, sendo 11 machos e 11 femeas mantidos em cativeiro de tres instituicoes diferentes. Todos os animais tiveram seus comportamentos registrados pelo metodo de amostragem focal por intervalo de tempo, durante seis meses, totalizando 4800 registros para cada animal. Amostras fecais foram coletadas tres vezes por semana, durante este periodo, para extracao e dosagem de metabolitos fecais de glicocorticoides por radioimunoensaio. Os comportamentos estereotipados representaram 13,45+2,76% do total observado, sendo que dentre estes comportamentos a automutilacao representou 38,28+3,98%. Os animais foram classificados em tres graus diferentes, de acordo com o percentual da superficie corporea com alopecia decorrente da automutilacao. Foi encontrada uma correlacao positiva de intensidade forte entre os graus de alopecia decorrentes de mutilacao observados e as medias de concentracoes de metabolitos fecais de glicocorticoides. Este resultado sugere fortemente que esta graduacao de automutilacao de um chimpanze possa ser utilizada como uma ferramenta auxiliar importante nas avaliacoes das condicoes de adaptacao do animal ao cativeiro, atuando como um indicador indireto da presenca de estresse cronico.

Fecal glucocorticoid metabolites and assay validation: Stress response evaluation in captive brown howler monkeys (Alouatta clamitans)

The advent of non‐invasive methods provides a powerful alternative to stress studies as the use of stressful handling techniques is no longer needed. However, many factors influence hormone metabolism such as sex, diet, and metabolic rate. Thus, validation should be species‐ and matrix‐specific.

Estradiol and progesterone fecal metabolites analysis in crab-eating-fox (Cerdocyoun thous)

In this study, four crab-eating fox females (Cerdocyon thous) maintained at the Federal University of Mato Grosso Zoo, Cuiaba, Brazil, were investigated for 12 months, using feces measurement of estradiol and progesterone concentrations. Fecal collections were performed three times a week for hormone extraction. Two methods of analysis, Elisa (EIA) and Radioimmunoassay (RIA), were used in the measurement of progesterone (P4) and estradiol (E2) metabolites. The aim of this study was to compare and validate two different methods of hormone measurement for C. thous. There were no differences regarding the method used. The Radioimmunoassay technique proved to be more sensitive, however, both showed similar results.

Identificação dos níveis séricos do fator de crescimento tipo insulina 1 em potros com osteocondrose

Osteochondrosis is the most common orthopaedic developmental disorder in horses and has been traditionally defined as a multifactorial disease. The disease had a very dynamic character in which the repair process starts almost immediately after the lesion has formed. The intensity and efficacy of this repair process is strongly age-related and is determined by the turnover rate of the components of the extracellular matrix of the articular cartilage. Since the insulin-like growth factor-I (IGF-1) acts regulating the growth of articular cartilage, this study aimed to describe the serum levels of IGF-1, insulin and glucose in healthy Lusitano foals and foals with osteochondrosis, from birth to 18 months of age. At one month 76.08% of the foals showed radiographic signs of osteochondrosis, but at age of 18 months the percentage dropped to 16.2%. The IGF-1 concentrations reached peak values at age of 14 to 16 months, equivalent to the onset of puberty. The IGF-1 concentrations in foals with osteochondrosis were lower than in healthy 2 to 5-month-old foals (P<0.05), and the insulin at age of 2 months (P<0.05). On farms with high incidence of osteocondrosis is recommended that measurement of serum IGF-1 and insulin occur during the first 6 months of age, to have enough time to establish preventive and therapeutic measures.