The radioactive tracer experiment indicated substantial metabolism of the [14C]testosterone resulting in only a small percentage of injected radiolabeled testosterone being excreted in the feces. Though measurable, androsterone and etiocholanone were not good indicators of testes function, probably because these steroids are also formed as metabolites of adrenal steroid secretion. Despite the extensive metabolism of testosterone, there is sufficient amount excreted to quantify using the ELISA. It should be noted that the effect that a single large dose of testosterone may have had on the metabolic profile was unknown. birth control yasmin
The production and release of endocrine-disrupting chemicals has been occurring for decades and is a concern in environmental research. These chemicals can suppress reproductive development in wild male mice, and this suppression is due in part to decreased production and release of testosterone. Because reproduction is not required for the immediate survival of the individual, fecundity may be reduced, and despite survival of the individual, important reduction in the quality and numbers of the succeeding generations could result.
In conclusion, the present study employed a technique for extracting and measuring fecal steroids that can measure androgen status of animals in the laboratory and field. Mus were studied because of their availability, the abundance of baseline data, and their prevalence in the fields of California. Peromyscus were chosen because they have many characteristics of good sentinel species for field studies. Feces can be easily collected in the field and frozen. With fecal analysis, samples can be collected frequently without the stress associated with venipuncture. This fecal testosterone biomarker should prove to be a valuable marker in the study of endocrine-disrupting chemicals on free-ranging wild mice.