Collaborative work on evaluation of ovarian toxicity. 15) Two- or four-week repeated-dose studies and fertility study of bromocriptine in female rats.
The main focus of this study is to determine the optimal administration period concerning toxic effects on ovarian morphological changes in a repeated-dose toxicity study. To assess morphological and functional changes induced in the ovary by bromocriptine, the compound was administered to female rats at dose levels of 0, 0.08, 0.4 and 2 mg/kg for the 2- or 4-week repeated-dose toxicity study, and for the female fertility study from 2 weeks prior to mating to day 7 of gestation. In the 2-week repeated-dose toxicity study, increase of ovarian weights was observed at 2 mg/kg. In the 4-week repeated-dose toxicity study, ovarian weights were increased at 0.4 and 2 mg/kg. The number of corpora luteum was increased in the 0.4 and 2 mg/kg groups of the 2- and 4-week repeated-dose toxicity studies by histopathological examination of the ovaries. Bromocriptine did not affect estrous cyclicity in 2- and 4-week repeated dosing. In the female fertility study, although animals in any groups mated successfully, no females in 0.4 and 2 mg/kg groups were pregnant. There were no adverse effects on reproductive performance in the 0.08 mg/kg group. Based on these findings, the histopathological changes in the ovary are considered important parameters for evaluation of drugs including ovarian damage. We conclude that a 2-week administration period is sufficient to detect ovarian toxicity of bromocriptine in a repeated-dose toxicity study.
Kumazawa
Toshihiko
T
Pharmaceutical Research Laboratories, Sanwa Kagaku Kenkyusho Co., Ltd., Inabe-shi, Mie, Japan. t_kumazawa@m4.skk-net.com
Nakajima
Atsushi
A
Ishiguro
Tsukasa
T
Jiuxin
Zhu
Z
Tanaharu
Takashi
T
Nishitani
Hiromi
H
Inoue
Yukiko
Y
Harada
Satoko
S
Hayasaka
Ikuo
I
Tagawa
Yoshiaki
Y
D000818:Animals; D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000633:toxicity*; D001971:Bromocriptine / Q000008:administration & dosage / Q000633:toxicity*; D003338:Corpus Luteum / Q000187:drug effects / Q000473:pathology; D004334:Drug Administration Schedule; D030762:Estrous Cycle / Q000187:drug effects; D005260:Female; D005298:Fertility / Q000187:drug effects*; D007247:Infertility, Female / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D007564:Japan; D008136:Longevity / Q000187:drug effects; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010049:Ovarian Diseases / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D010902:Pituitary Gland / Q000187:drug effects / Q000473:pathology; D011247:Pregnancy; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D055818:Public-Private Sector Partnerships; D051381:Rats; D017207:Rats, Sprague-Dawley; D012958:Societies, Scientific; D018675:Toxicity Tests / Q000379:methods*
D000978:Antiparkinson Agents; D018809:Proliferating Cell Nuclear Antigen; D001971:Bromocriptine