Changes in the fecal concentrations of cortisol and androgen metabolites in captive male jaguars (Panthera onca) in response to stress

In the present study we determined the efficacy of the measurement of fecal cortisol and androgen metabolite concentrations to monitor adrenal and testicular activity in the jaguar (Panthera onca). Three captive male jaguars were chemically restrained and electroejaculated once or twice within a period of two months. Fecal samples were collected daily for 5 days before and 5 days after the procedure and stored at -20ºC until extraction. Variations in the concentrations of cortisol and androgen metabolites before and after the procedure were determined by solid phase cortisol and testosterone radioimmunoassay and feces dry weight was determined by drying at 37ºC for 24 h under vacuum. On four occasions, fecal cortisol metabolite levels were elevated above baseline (307.8 ± 17.5 ng/g dry feces) in the first fecal sample collected after the procedure (100 to 350 percent above baseline). On one occasion, we did not detect any variation. Mean (± SEM) fecal androgen concentration did not change after chemical restraint and electroejaculation (before: 131.1 ± 26.7, after: 213.7 ± 43.6 ng/g dry feces). These data show that determination of fecal cortisol and androgen metabolites can be very useful for a noninvasive assessment of animal well-being and as a complement to behavioral, physiological, and pathological studies. It can also be useful for the study of the relationship between adrenal activity and reproductive performance in the jaguar.

Perfil electroforético de deshidrogenasas de pentosas en vertebrados: órdenes carnívora y lagomorpha / Electrophoretic profile of pentose dehydrogenases in vertebrates: carnivorous and lagomorpha order

Deshidrogenasas de pentosas NAD o NADP dependientes fueron aisladas de riñón, corazón, cerebro e hígado de perro y conejo. La electroforesis en geles de policrilamida de los extractos enzimáticos, reveló la presencia de varias bandas con actividad deshidrogenásica. En perro, los diferentes órganos estudiados, mostraron actividad enzimática NADP-dependiente, con amplia especificidad de sustrato. También estos órganos exhibieron una deshidrogenasa que utilizaba al cofactor NAD como aceptor de hidrógeno. Su sustrato preferido fue D-arabinosa. Los extractos de hígado y de riñón de conejo fueron activados con NADP o NAD usando D-arabinosa como sustrato. Los extractos de riñón revelaron una actividad adicional para D-aribosa y NAD. La presencia de este tipo de deshidrogenasas de pentosas, sugiere que en mamíferos las pentosas puden ser utilizadas por una vía diferente a la de pentosa-fosfato