In conclusion, thus far the studies conducted on human males generally reveal an insignificant effect of coenzyme Q10 supplementation on testosterone levels. Specifically, coenzyme Q10 supplementation was found to significantly suppress testicular oxidative stress and lipid peroxidation, and restore the antioxidant defense mechanism , which in turn can counteract chemical oxidative injury and maintain the function of Leydig cells to produce testosterone . In all of these studies, coenzyme Q10 was found to counteract the reduction in testosterone levels. The last three studies in the table are reproductive toxicity studies, which measured the influence of coenzyme Q10 on testosterone levels after testicular injury by a chemical toxicant. In this study the activity level of CAT, POD, SOD in testes samples of CCl4 treated rats decreased as compared to the control group (Fig. 1). CAMP (A) and testosterone production (B and C) by Leydig cells isolated from 4-month-old (young) and 24-month-old (old) rats that were treated with BSO or vehicle (PBS) for 7 d. Cells from BSO-treated young and old rats produced significantly less testosterone than the cells from age-matched control animals when the cells were incubated with dbcAMP (Fig. 6B) or 25-HC (Fig. 6C). With 1 wk of BSO treatment, cells isolated from rats of both ages produced significantly less testosterone than their age-matched controls whether or not the cells were stimulated with LH. GSH content (A) and testosterone production (B) by Leydig cells isolated from 4-month-old rats and cultured without (C) or with BSO (100 μm) or BSO plus the antioxidants vitamin E (VE; 40 μg/ml), BPN (1 mm), or Trolox (100 μm) (B). Elevate your T levels and you’ll boost your muscle mass, strength and athleticism – you’ll look and feel better. However, consistent training also stimulates the body to upgrade its own antioxidant defense systems over time. Intense exercise does create significant oxidative stress, which can temporarily tax glutathione stores. For research purposes, precursors like N-acetylcysteine (NAC) are often studied to help the body produce its own glutathione. In an environment rich with glutathione, the Leydig cells can do their job efficiently. The link between glutathione and testosterone is a perfect example of that web. In the brain and bone, testosterone is converted by aromatization into estradiol, which binds to estrogen receptors . In the liver, testosterone enhances protein synthesis, while in muscles, testosterone enhances muscle mass . Testosterone is primarily synthesized in Leydig cells, which are stimulated by the luteinizing hormone (also called lutropin) , which is a glycoprotein hormone secreted from the gonadotropic cells in the pituitary gland in response to the gonadotropin-releasing hormone . In human males, about 95% of testosterone is synthesized in the testis, and the remainder (≈5%) is synthesized by other organs, mostly the adrenal gland . To determine whether BSO treatment of the rats affected Leydig cell viability, the freshly isolated cells were incubated with 0.5 mg/ml MTT for 1 h. To this end, young and old rats were treated with BSO at a dose of 2 mmol/kg body weight at 12-h intervals for 7 d. Leydig cells isolated from the testes of 4-month-old rats were cultured without (0) or with BSO (3.1–100 μm) in vitro for 48 h.
