When organisms are stressed by changes in the environment, their energies are utilized for immediate survival, and reproductive potential is reduced. Thus, a reduction of fecundity, or reproductive potential, can be used as a measure of the adverse effects or cumulative negative impact of adverse environmental changes altering the fitness of an organism. This paper describes a method of measuring changes in reproductive potential by looking at changes in steroid levels. buy flovent inhaler
Conventional methods of assessing the reproductive health of males require invasive procedures and only infer endocrine function. These methods include determination of number of sperm in the testis, epididymis, or ejaculate; measures of sperm function; and histopathology. Serum steroid measurements require invasive procedures such as collection of blood samples and expensive assays. While it is well accepted that measurements of reproductive hormones, such as testosterone, are an adequate measure of reproductive potential, they have to be adapted to field studies. The objective of the present study was to develop a simple method for extraction and measurement of testosterone from feces of male rodents and to employ this parameter as a noninvasive biomarker of reproductive stress in Peromyscus maniculatus. This study was an examination of methods for extraction of fecal testosterone and its subsequent measurement using a competitive ELISA.