Products

• RecoveryMatrix
• VitalityMatrix
• Varimune100
• FlexMatrix
• FlexPro
• OmegaMatrix
• FlexAid
• TerreMatrix
• PhytoMatrix
• MSMPro
• SkinMatrix
• SkinPro
• Thyrovus
• Acnevus
• E-reXX
• SkinBalm

Back

Testosterone is a steroid hormone from the androgen group.

Testosterone is secreted in the testes of men and the ovaries of women. It is the principal male sex hormone. In both males and females, it plays key roles in health and well-being. Testosterone is derived from cholesterol just like other steroid hormones. The largest amounts of testosterone are produced by the testes in men, but it is also synthesized in smaller quantities in women by the theca cells of the ovaries, by the placenta.

Testosterone effects can be classified as virilizing and anabolic effects, although the distinction is somewhat artificial, as many of the effects can be considered both. Anabolic effects include growth of muscle mass and strength, increased bone density and strength, and stimulation of height growth and bone maturation. Virilizing effects include maturation of the sex organs, particularly the penis and the formation of the scrotum in fetuses, and after birth (usually at puberty) a deepening of the voice, growth of the beard and torso hair.

Anabolic steroids have also been taken to enhance muscle development, strength, or endurance. After a series of scandals and publicity in the 1980s (such as Ben Johnson's improved performance at the 1988 Summer Olympics), prohibitions of anabolic steroid use were renewed or strengthened by many sports organizations, and it was made a "controlled substance" by the United States Congress.

Androgens with activity at estrogen receptor beta have anxiolytic and cognitive-enhancing effects in male rats and mice.

Horm Behav. 2008 Aug 8. [Epub ahead of print]

Frye CA, Koonce CJ, Edinger KL, Osborne DM, Walf AA.
Department of Psychology, The University at Albany-SUNY, USA; Department of Biological Sciences, The University at Albany-SUNY, USA; The Center for Life Sciences, The University at Albany-SUNY, USA; The Center for Neuroscience Research, The University at Albany-SUNY, USA.

Testosterone (T) and its metabolites may underlie some beneficial effects for anxiety and cognition, but the mechanisms for these effects are unclear. T is reduced to dihydrotestosterone (DHT), which can be converted to 5alpha-androstane,3alpha,17beta-diol (3alpha-diol) and/or 5alpha-androstane-3beta,17beta-diol (3beta-diol). Additionally, T can be converted to androstenedione, and then to androsterone. These metabolites bind with varying affinity to androgen receptors (ARs; T and DHT), estrogen receptors (ERbeta; 3alpha-diol, 3beta-diol), or GABA(A)/benzodiazepine receptors (GBRs; 3alpha-diol, androsterone). Three experiments were performed to investigate the hypothesis that reduced anxiety-like and enhanced cognitive performance may be due in part to actions of T metabolites at ERbeta.

Experiment 1: Gonadectomized (GDX) wildtype and ERbeta knockout mice (betaERKO) were subcutaneously (SC) administered 3alpha-diol, 3beta-diol, androsterone, or oil vehicle at weekly intervals, and tested in anxiety tasks (open field, elevated plus maze, light-dark transition) or for cognitive performance in the object recognition task.

Experiment 2: GDX rats were administered SC 3alpha-diol, 3beta-diol, androsterone, or oil vehicle, and tested in the same tasks. Experiment 3: GDX rats were androsterone- or vehicle-primed and administered an antagonist of ARs (flutamide), ERs (tamoxifen), or GBRs (flumazenil), or vehicle and then tested in the elevated plus maze. Both rats and wildtype mice, but not betaERKO mice, consistently had reduced anxiety and improved performance in the object recognition task. Androsterone was only effective at reducing anxiety-like behavior in the elevated plus maze and this effect was modestly reduced by flumazenil administration. Thus, actions at ERbeta may be required for T's anxiety-reducing and cognitive-enhancing effects.

---

Semen quality according to prenatal coffee and present caffeine exposure: two decades of follow-up of a pregnancy cohort.

Ramlau-Hansen CH, Thulstrup AM, Bonde JP, Olsen J, Bech BH.
Department of Occupational Medicine, Aarhus University Hospital, Norrebrogade 44, Building 2C, DK-8000 Aarhus C, Denmark.

BACKGROUND A few studies have investigated the association between male caffeine consumption in adult life and semen quality with conflicting results, but so far no studies have explored the effect of prenatal coffee exposure. We studied the association between prenatal coffee and current caffeine exposure and semen quality and levels of reproductive hormones.

METHODS From a Danish pregnancy cohort established in 1984-1987, 347 sons out of 5109 were selected for a follow-up study conducted 2005-2006. Semen and blood samples were analyzed for conventional semen characteristics and reproductive hormones and were related to information on maternal coffee consumption during pregnancy and present caffeine consumption. Data were available for 343 men.

RESULTS There was a tendency toward decreasing crude median semen volume (P = 0.06) and adjusted mean testosterone (P = 0.06) and inhibin B (P = 0.09) concentrations with increasing maternal coffee consumption during pregnancy. Sons of mothers drinking 4-7 cups/day had lower testosterone levels than sons of mothers drinking 0-3 cups/day (P = 0.04). Current male caffeine intake was associated with increasing testosterone levels (P = 0.007). Men with a high caffeine intake had approximately 14% higher concentration of testosterone than those with a low caffeine intake (P = 0.008).

CONCLUSIONS The results observed in this study are only tentative, but they do not exclude a small to moderate effect of prenatal coffee exposure on semen volume and levels of reproductive hormones. Present adult caffeine intake did not show any clear associations with semen quality, but high caffeine intake was associated with a higher testosterone concentration.