Differential effects of estrogen metabolites on bone and reproductive tissues of ovariectomized rats.
J Bone Miner Res
; 13(6): 1023-31, 1998 Jun.
Article
em En
| MEDLINE
| ID: mdl-9626634
ABSTRACT
The effects of 17 beta-estradiol and the important estrogen metabolites, 2-hydroxyestrone (2-OHE1) and 16 alpha-hydroxyestrone (16 alpha-OHE1) on bone, mammary gland, and uterine histology, and on blood cholesterol were investigated in ovariectomized growing rats. Rats were treated with 200 micrograms/kg of body weight/day of each of the test compounds for 3 weeks. Ovariectomy resulted in uterine and mammary gland atrophy, increased body weight, bone turnover and tibia growth, and hypercholesterolemia. 17 beta-estradiol treatment prevented these changes, with the exception that this high dose of estrogen did not prevent hypercholesterolemia. 2-OHE1 had no effect on any of the measurements. 16 alpha-OHE1 resulted in bone measurements that did not differ from the 17 beta-estradiol-treated rats and prevented the increase in serum cholesterol. In contrast, 16 alpha-OHE1 resulted in increases in uterine weight, uterine epithelial cell height, and mammary gland cell proliferation that were significantly less than the 17 beta-estradiol treatment. These findings demonstrate that 16 alpha-hydroxylation of estrone results in tissue-selective estrogen agonistic activity, whereas 2-hydroxylation resulted in no measured activity. Furthermore, they suggest that factors that modulate the synthesis of these metabolites could selectively influence estrogen target tissues.
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Base de dados:
MEDLINE
Assunto principal:
Útero
/
Anticarcinógenos
/
Estradiol
/
Hidroxiestronas
/
Glândulas Mamárias Animais
Idioma:
En
Ano de publicação:
1998
Tipo de documento:
Article