Age-related testosterone declines can be detected in men's fingernails.

Testosterone plays multiple roles in the regulation of development, physiology, reproduction, and behavior. Age-related testosterone declines are expected in the population. However, measuring circulating testosterone is especially challenging because concentrations are labile, responding to social situations and challenges. Matrices that integrate long-term testosterone levels are therefore valuable as biomarkers of endogenous levels as well as chronic exposures. Here, we report on a simple method to extract and measure accumulated testosterone from human fingernails using commercial enzyme immunoassay kits. Furthermore, we demonstrate known human testosterone sex and age trends. Our method is especially useful for quantifying testosterone in men's nails, where a small amount of matrix is required. Thus, this approach is a potential tool for biomonitoring endogenous as well as exogenous testosterone exposure. We suggest considering nails as an alternative matrix for quantifying other steroids as well.

Endogenous testosterone levels and visuospatial ability / 中华行为医学与脑科学杂志

To describe the effects of endogenous testosterone levels on the visuospatial ability.Thevisuospatial ability,testosteronewere included as the key words,retrieving 46 papers in the database.35 relevant papers have been reviewed in the paper,as the results,we have found that the visuospatial ability of male was better than female.The performances of the visuospatial tasks in males were associated with the lev-els of endogenous testosterone,and the effects comprised two aspects:the organizational function and activa-tional function of the testosterone.The latter have received more attention from researchers.Until now,most studies of activational effects of testosterone on visuospatial ability remained on the level of behavioral re-search.The mental rotation task,navigation task and virtual reality scenes tasks were implied in these stud-ies.A nonlinear relationship has aroused a great controversy.Latest research suggests that further investiga-tion of the neural mechanisms related to visual-spatial ability is needed,using ERP and MRI techniques,to assess the relationship of endogenous testosterone levels with the relevant neural basis of visuospatial ability.