title: Plasma levels of steroid glucuronides in prepubertal, adult and elderly men.
abstract: The present study has been designed to measure the levels of C-19 steroids and their glucuronide derivatives (G) in the plasma of males at three different ages: (1) 4-7 years old, (2) 20-35 years old and (3) 55-70 years old. In 4-7 years old, the plasma levels of the free and conjugated C-19 steroids were almost undetectable. From the data obtained in both groups of adult men, it appeared that except for androsterone, the levels of all free C-19 steroids were diminished by 10-70% during aging. In adult men, androsterone-G was the predominant C-19 steroid-G in plasma. The levels of androsterone-G, in the group of 20-35 years old, exceed by 3 and 20-fold the levels of androstane-3 alpha, 17 beta-diol-G and androstane-3 beta, 17 beta-diol-G, respectively. During aging, while the levels of androsterone-G and androstane-3 beta, 17 beta-diol-G were decreased or in the case of androstane-3 alpha,17 beta-diol-G remained unchanged, testosterone-G and dihydrotestosterone-G levels were markedly increased, suggesting a modification in the action of glucuronyl transferase during aging.
mesh_terms: D000328:Adult; D000368:Aged; D000728:Androgens / Q000097:blood*; D015113:Androstane-3,17-diol / Q000031:analogs & derivatives / Q000097:blood; D000735:Androstenedione / Q000097:blood; D000738:Androsterone / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003687:Dehydroepiandrosterone / Q000097:blood; D013196:Dihydrotestosterone / Q000097:blood; D005965:Glucuronates / Q000097:blood*; D006801:Humans; D008297:Male; D011627:Puberty; D013739:Testosterone / Q000097:blood
chemical_list: D000728:Androgens; D005965:Glucuronates; D013196:Dihydrotestosterone; D015113:Androstane-3,17-diol; C028895:androstane-3,17-diol glucuronide; D013739:Testosterone; D000735:Androstenedione; D003687:Dehydroepiandrosterone; D000738:Androsterone