TY - JOUR
T1 - Tibolone induces serotonin, estrogen, and progesterone receptor expression but not contractile response to serotonin in the rat uterus
AU - Oropeza, M.
AU - Calzada, C.
AU - Guerra-Araiza, C.
AU - Bazan-Perkins, B.
AU - Mendoza-Espinoza, J. A.
AU - Campos-Lara, M. G.
PY - 2013
Y1 - 2013
N2 - Most studies on the effect of tibolone on the uterus have focused on the endometrium dismissing the importance of the myometrium. The aim of the present study was to investigate some estrogen-like actions of tibolone in the uterus assessed by: 1) the expression of estrogen, progesterone, and serotonin receptors, and 2) the myometrial contraction induced by serotonin. Estradiol (250 μg), progesterone (50 mg), or testosterone (25 mg) pellets were implanted to ovariectomized rats. Tibolone (0.5 mg/day) was orally administered. An implanted pellet containing vehicle or an equivalent volume of water p.o., were used as controls. Sixty days after beginning the treatments, rats were killed and uterus removed. One horn was processed to evaluate estrogen-alpha, progesterone A and B, and serotonin-2A receptors expression, and the other one was used for studying contraction to serotonin and 60 mM potassium solution. The present data showed that tibolone-induced expression of estrogen, progesterone, and serotonin receptors, but did not induce uterine contractile response to either serotonin or potassium solution. These findings suggest that, in the uterus, tibolone may exert molecular estrogenic actions such as the induction of receptor expression, but not a physiological response as the estrogen-dependent contraction to serotonin.
AB - Most studies on the effect of tibolone on the uterus have focused on the endometrium dismissing the importance of the myometrium. The aim of the present study was to investigate some estrogen-like actions of tibolone in the uterus assessed by: 1) the expression of estrogen, progesterone, and serotonin receptors, and 2) the myometrial contraction induced by serotonin. Estradiol (250 μg), progesterone (50 mg), or testosterone (25 mg) pellets were implanted to ovariectomized rats. Tibolone (0.5 mg/day) was orally administered. An implanted pellet containing vehicle or an equivalent volume of water p.o., were used as controls. Sixty days after beginning the treatments, rats were killed and uterus removed. One horn was processed to evaluate estrogen-alpha, progesterone A and B, and serotonin-2A receptors expression, and the other one was used for studying contraction to serotonin and 60 mM potassium solution. The present data showed that tibolone-induced expression of estrogen, progesterone, and serotonin receptors, but did not induce uterine contractile response to either serotonin or potassium solution. These findings suggest that, in the uterus, tibolone may exert molecular estrogenic actions such as the induction of receptor expression, but not a physiological response as the estrogen-dependent contraction to serotonin.
KW - estrogenic actions
KW - myometrial response
KW - receptor expression
KW - serotonin
KW - tibolone
UR - http://www.scopus.com/inward/record.url?scp=84879506171&partnerID=8YFLogxK
U2 - 10.1055/s-0033-1337932
DO - 10.1055/s-0033-1337932
M3 - Artículo
SN - 0018-5043
VL - 45
SP - 490
EP - 494
JO - Hormone and Metabolic Research
JF - Hormone and Metabolic Research
IS - 7
ER -