Seasonal Changes in Fecal Cortisol Metabolites in Pyrenean Chamois

Abstract: We studied seasonal changes in fecal Cortisol metabolites (FCM), which have been widely used as indicators of stress, in a population of Pyrenean chamois (Rupicapra pyrenaica pyrenaica) in the Cadí Range of northeastern Spain. We collected fecal samples from 2001 to 2003 in 3 particular locations with different altitudes and male or female presence, and we analyzed them for FCM and fecal nitrogen as an indicator of diet quality. We observed a clear seasonal pattern, with the highest FCM in winter, and we obtained correlations between FCM and monthly mean minimum temperatures and fecal nitrogen. We observed no effects of tourism presence, trophy hunting, or rut season on FCM. Analysis of cortisol metabolites in feces can be a good measure of winter stress in Pyrenean chamois.     

Expression and activity of 3-hydroxy-3-methylglutaryl-CoA synthase and reductase in the fat body of ovariectomized and allatectomized Blattella germanica

Abstract. . 3-Hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and HMG-CoA reductase show coordinated regulation in the fat body of Blattella germanica females. Since the profile of activity is parallel to the cycle of vitellogenin production, we postulated a link between the mevalonate pathway and vitellogenesis. Here we have studied both enzymes in females of B.germanica modified by ovariectomy (which leads to a saturable accumulation of vitellogenin) and allatectomy (which supresses vitellogenesis). Protein levels and enzymatic activity for both enzymes in ovariectomized specimens rose early in the first days of imaginal life and remained high until the end of the period studied, whereas controls showed cyclic profiles. In allatectomized specimens the same parameters were measured on day 4 of adult life and values were much lower with respect to controls. The parallelism between the patterns of HMG-CoA synthase and reductase, and that of vitellogenin, suggests a functional relationship between the mevalonate pathway and the glycosylation of vitellogenin through dolichol intermediates.