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New method for detecting antiandrogenic effects through the measurement of external genitalia in rabbits
Author(s) -
Inawaka Kunifumi,
Kishimoto Noriyuki,
Higuchi Hashihiro,
Okamoto Takayuki,
Kawamura Satoshi
Publication year - 2010
Publication title -
congenital anomalies
Language(s) - English
Resource type - Journals
eISSN - 1741-4520
pISSN - 0914-3505
DOI - 10.1111/j.1741-4520.2009.00251.x
Subject(s) - preputial gland , penis , fetus , endocrinology , antiandrogen , medicine , anogenital distance , lamella (surface anatomy) , biology , anatomy , andrology , pregnancy , androgen , hormone , in utero , genetics
The aim of the present study was to develop a quantitative evaluation method for detecting antiandrogenic activity of chemicals in rabbits that are regularly used for developmental toxicity studies. Kbl: New Zealand White rabbits ( n = 8–9) were injected intramuscularly with an antiandrogen, cyproterone acetate (CA; 10 mg/kg body weight [BW]/day), on gestation days (GD) 13–24. On GD 29, live fetuses were obtained by cesarean section and sexed by examination of the internal genitalia. The external genitalia were evaluated in cross‐section measurements of the phallus by both diameter and width of the ventral gap of the preputial lamella with a micrometer under a stereoscopic microscope. The diameters of the preputial lamella were 1015 ± 83.5, 856 ± 64.0, and 865 ± 72.6 µm in control males, control females, and CA‐treated males, respectively. The ventral gaps of the preputial lamella were 26 ± 8.2, 437 ± 72.3, and 318 ± 59.4 µm in the control males, control females, and CA‐treated males, respectively. There were statistically significant differences in both parameters between control males and control females or CA‐treated males. The lower fetal BW in CA‐treated males did not disturb the detection of the feminization of the ventral gap of the preputial lamella; however, the diameter of the preputial lamella might be influenced by fetal BW because no difference in the relative diameter of the preputial lamella was found between control males and CA‐treated males. These results demonstrated that this approach could detect the antiandrogen activity of CA quantitatively by feminization of male external genitalia in rabbit fetuses.