Measurement of thyroid hormones (thyroxine, T4; triiodothyronine, T3) in captive nondomestic felids.

The aim of this research was to obtain basic values for the evaluation of thyroid function in nondomestic felids. Serum thyroid hormone concentrations (thyroxine, T4; triiodothyronine, T3) were measured by radioimmunoassay in 145 cats, representing nine species of captive nondomestic felids: jaguar (Panthera onca), n = 49; puma (Puma concolor), n = 10; ocelot (Leopardus pardalis), n = 22; oncilla (Leopardus tigrinus), n = 12; geoffroy (Oncifelis geoffroyi), n = 4; jaguarundi (Herpailurus yaguarondi), n = 8; margay (Leopardus wiedii), n = 7; lion (Panthera leo), n = 26; and tiger (Panthera tigris), n = 7. For each species, mean +/- SEM of T3 and T4, respectively, were as follows: jaguar, 0.

Assessment of the physiologic stress response by quantification of fecal corticosteroids.

Noninvasive techniques to monitor reproductive or stress hormones are now widely used in captive and free-ranging wildlife. These methods offer great advantages and deserve to be used also in laboratory rodents. However, we remain naïve about factors that may influence the accuracy of these techniques.

Impaired female sexual behavior of rat offspring exposed to Solanum lycocarpum unripe fruits during gestation and lactation: lack of hormonal and fertility alterations.

Solanum lycocarpum St. Hil (Solanaceae) is an invasive and native shrub very common in the Brazilian savanna. It is well known that this plant contain steroidal glycoalkaloids that can be transformed into an intermediate for steroidal drugs production, like oral contraceptives.