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Early Estrogenic Effect Of High Dose Of Tibolone In Castrated Rats
Author(s) -
GuzmanSilva Maria Angelica,
Pantaleão Jose Augusto S.,
Pollastri Carlos Eduardo,
HugoSilva Ivanisia,
Henriques Helene N.,
Pereira Junior Paulo M.,
De Carvalho Ana Carolina B.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1132-c
Subject(s) - tibolone , estrous cycle , medicine , endocrinology , hormone , weight loss , medroxyprogesterone , estrogen , medroxyprogesterone acetate , obesity
Tibolone is a synthetic steroid hormone with estrogenic, androgenic and progestogenic action through different metabolites. Estrogenic effect of high dose of tibolone was evaluated in the body weight and vagina of castrated rats. Wistar rats weighing 215±18g were divided in 2 groups: control (CG), carboxymethylcellulose 0.5% (n=8) and tibolone (TG), 1mg/day/animal (n=10). All rats were weighed weekly. Vaginal smears were collected at days 0, 1 to 6, 30 and 60, fixed in 95% alcohol and stained (Papanicolaou). At day 0 eighteen rats had atrophic smear (anestrus). From day 0 to 60 all rats in CG were in anestrus. Between days 2 and 3 all rats in TG had typical estrogenic smear (estrus). At the first week of daily administration per os, both groups lost weight (4.26% and 8.43%). TG had progressive weight loss (213±21g), while the CG had weight gain (246±16g) (T test p<0.01). Food consumption was lower in the animals given tibolone (12±1.9g vs. 14±2.7g), possibly due to tibolone side effects, e.g. nausea and appetite loss, thus accounting for weight loss. Tibolone has a strong estrogenic action in the vaginal epithelium, soon after the first high dose. (Supported by OFFICILAB)