Serum analysis testosterone

A complete physical examination and laboratory analysis are needed to rule out secondary causes and to assess kyphosis and back pain. Laboratory testing may include complete blood count, liver function tests, creatinine, urea nitrogen, calcium, phosphorus, alkaline phosphatase, albumin, thyroid-stimulating hormone, free testosterone, 25-hydroxyvitamin D, and 24-hour urine concentrations of calcium and phosphorus. Urine or serum biomarkers (e.g., cross-linked N-telopeptides of type 1 collagen, osteocalcin) are sometimes used. 

Data from animal studies suggest that exposure to excessive selenium has adverse effects on testosterone levels and sperm production and increases the percentage of abnormal sperm (El-Zarkouny et al. 1999 Kaur and Parshad 1994 NTP 1994). A significant reduction (49%) in serum testosterone levels was reported for New Zealand White rabbits gavaged with 0.3 mg selenium/kg (0.001 mg selenium/kg/day) as sodium selenite once a week for 6 weeks (El-Zarkouny et al. 1999). The percentage of spermatozoa without an acrosome was also increased in treated rabbits compared with controls, but the difference was not significant. Sperm motility, ejaculate volume, sperm concentration, and total sperm output were all reduced by selenium treatment, but statistical analysis of these data was not presented. 

In addition, analysis of hormone levels in serum samples of white sucker Catostomus commersoni) in Lake Superior have been used to complement measurements of physiological response significant differences in the levels of testosterone and estradiol in females, and of testosterone levels in males have been associated with pollution by bleachery effluents (Munkittrick et al. 1991). It has been observed that feral fish captured from areas exposed to established contamination by PAHs, PCBs, and mercury did not exhibit the increased levels of hydrocortisone normally resulting from capture (Hontela et al. 1992). These results were interpreted as showing the adverse effect on sterol metabolism in fish chronically exposed to such pollutants. Collectively, such data draw attention to the subtler effects of exposure to xenobiotics. 

Dehydroepiandrosterone (DHEA), a naturally occurring precursor of endogenous testosterone synthesis, assnmed national attention following its use in professional baseball. Unlike the parenteral administration of testosterone, however, DHEA does not produce a notable elevation in serum testosterone levels or enhance skeletal mnscle hypertrophy.Several adverse effects were reported and the International Olympic Committee considers DHEA an illegal steroid, banning its use. A recent analysis of sixteen commercial DHEA products revealed that only half the products contained the actual amount of DHEA stated on the product label, with actual levels varying between 0% and 150% of the label content. ... 

Other SPME-IMS methods that have been reported for application to pharmaceutical or related samples include those for analysis of ephedrine in urine, meth-amphetamines in human serum, and captopril in human plasma and pharmaceutical preparations. In a method similar to SPME-IMS, testosterone was collected with a molecular imprinted polymer from urine and desorbed into an IMS. The method was validated with HPLC and determined to have a detection limit of 0.9 ng/mL with a linear dynamic range from 10 to 250 ng/mL. ... 

Higashi, T. Ninomiya, Y. IwaM, N. Yamauchi, A. Takayama, N. Shimada, K. Studies on neurosteroids XVin. LC-MS analysis of changes in rat brain and serum testosterone levels induced by immobilization stress and ethanol administration. Steroids 2006, 71 (7), 609-617. 

---