Link:
ncbi.nlm.nih.gov/pubmed/2277725
Plasma 5 alpha-androstane-3 alpha, 17 beta diol (Adiol) glucuronide levels were determined using a reliable radioimmunoassay involving hydrolysis with E. coli beta-glucuronidase, diethylether extraction, and Celite column chromatography. Conditions ensuring optimal hydrolysis were determined as well as quality control criteria. Sixty-eight male out-patients wre studied. These subjects were divided into three age groups: I (n = 21; age 20-35 years), II (n = 21; age: 36-50 years), and III (n = 26; age: 51-70 years). Patients under 50 years of age had infertility with no abnormalities upon sperm analysis. Older patients had erectile dysfunction. All subjects had serum gonadotropin (FSH and LH) and prolactin levels within the normal range for age. Adiol glucuronide levels (mean +/- SD) were as follows: 5.0 +/- 2.2 ng/ml (range: 1.6-9.5), 5.4 +/- 3.8 ng/ml (range 1.4-16.0) and 4.5 +/- 2.5 ng/ml (range 1.2-9.3) in groups I, II and III respectively. A trend towards lower Adiol glucuronide levels with advancing age was found but there was no significant difference between group III and the other two groups. Similarly, no significant correlation was found between Adiol glucuronide levels and age (r = -0.12). Conversely, a significant correlation (r = 0.37; p less than 0.01) was observed between Adiol glucuronide levels and bioavailable testosterone (T) levels. This finding might be the consequence of a certain enhancement of 5 alpha-reductase activity with age and/or the non significant decrease with age of another precursor.