Changes in serum alpha2u-globulin levels in castrated male rats treated with testosterone propionate in a Hershberger assay.
The Hershberger assay has been proposed as a candidate screening test method for the detection of androgenic and anti-androgenic chemicals and is being validated presently under the test guideline programme of the Organization for Economic Cooperation and Development (OECD). Rat alpha2u-globulin is male rat-specific protein appearing in their serum and urine, and the protein is known to be induced by androgens. We investigated the usefulness of measuring serum alpha2u-globulin levels as a parameter for the androgenic activity of chemicals tested in the Hershberger assay. The serum alpha2u-globulin level was measured after the administration of testosterone propionate at dosages of 0, 20, 100 or 500 microg kg(-1) day(-1) for ten consecutive days in the castrated male rats. The ventral prostate, balbocavernosus/levator ani muscles, glans penis and Cowper's gland were collected and weighed. Although all the androgen-responsive organ weights were increased significantly at dosages of 100 and 500 microg kg(-1) day(-1), the serum alpha2u-globulin level was increased significantly only at a dosage of 500 microg kg(-1) day(-1). These results show that the serum alpha2u-globulin level may be a useful biomarker for detecting androgenic activity caused by test chemicals, but it is less sensitive than the organ weights of androgen-responsive tissues in the Hershberger assay.
Takeyoshi
Masahiro
M
Hita Laboratory, Chemicals Evaluation and Research Institute, 3-822 Ishii-machi, Hita-shi, Oita 8770061, Japan. takeyoshi-masahiro@ceri.jp
Mitoma
Hideo
H
Yamasaki
Kanji
K
D000510:Alpha-Globulins / Q000187:drug effects*; D000726:Androgen Antagonists / Q000008:administration & dosage / Q000633:toxicity*; D000728:Androgens / Q000097:blood; D000818:Animals; D015415:Biomarkers / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005069:Evaluation Studies as Topic; D008297:Male; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012680:Sensitivity and Specificity; D043343:Testosterone Propionate / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
D000510:Alpha-Globulins; D000726:Androgen Antagonists; D000728:Androgens; D015415:Biomarkers; C013803:alpha 2u globulin; D043343:Testosterone Propionate