Testosterone ELISA

Intended Use

The DRG Testosterone ELISA is an enzyme immunoassay for the quantitative in vitro diagnostic measurement of testosterone in serum or plasma (EDTA, lithium heparin or citrate plasma)

Summary and Explanation

Testosterone is the major androgenic steroid hormone. It is responsible for the development of the male external genitalia and secondary sexual characteristics. In females, its main role is as an estrogen precursor. In both genders, it also exerts anabolic effects and influences behavior. In men, testosterone is secreted by the testicular Leydig cells and, to a minor extent, by the adrenal cortex. At puberty, testosterone increases dramatically in boys and progressively declines starting between the fourth and sixth decades of life. In premenopausal women, the ovaries are the main source of testosterone with minor contributions by the adrenals and peripheral tissues. After menopause, ovarian testosterone production is significantly diminished. Testosterone production in testes and ovaries is regulated via pituitary-gonadal feedback involving luteinizing hormone (LH) and, to a lesser degree, inhibins and activins. 40-50 % of the total testosterone in blood is bound with high affinity to sex hormone-binding globulin (SHBG), while 40-50 % is bound with low affinity to albumin, and only 1 2 % can be detected as unbound or free testosterone. Free Testosterone and albumin-bound Testosterone are considered bioactive. In men, mild-to-moderate testosterone elevations are usually asymptomatic while high levels of testosterone are associated with hypothalamic-pituitary-unit dysfunction, testicular tumors, congenital adrenal hyperplasia, prostate cancer or intake of anabolic steroids. Male testosterone levels below the reference range indicate partial or complete hypogonadism, caused either by primary or secondary/tertiary (pituitary/hypothalamic) testicular failure. Low levels of testosterone are encountered in male patients with the following diseases: primary hypogonadism (e.g. Klinefelter´s syndrome), testicular feminization, orchidectomy, congenital cryptorchidism, enzymatic defects, anorexia, liver cirrhosis, drug abuse, or prepubescent intake of anabolic steroids. In adult women, excess testosterone production results in varying degrees of virilization, including hirsutism, acne, oligo-amenorrhea. Increased testosterone levels may be caused by polycystic ovaries, ovarian and adrenal tumors, adrenal hyperplasia, Cushing´s syndrome, or congenital adrenal hyperplasia. Decreased testosterone in females can be caused by primary or secondary insufficiency of the ovaries, intake of ovulation blockers, liver cirrhosis, drug abuse, Addison´s disease or anorexia. Symptoms of low testosterone may include decline in libido and nonspecific mood changes.