Home
Resources
Publications
The Effects of Steroidal Estrogens in ACI Rat Mammary Carcinogenesis: 17beta-estradiol, 2-hydroxyestradiol, 4-hydroxyestradiol, 16alpha-hydroxyestradiol, and 4-hydroxyestrone

The Effects of Steroidal Estrogens in ACI Rat Mammary Carcinogenesis: 17beta-estradiol, 2-hydroxyestradiol, 4-hydroxyestradiol, 16alpha-hydroxyestradiol, and 4-hydroxyestrone

V K Turan, R I Sanchez, J J Li, S A Li, K R Reuhl, P E Thomas, A H Conney, M A Gallo, F C Kauffman, S Mesia-Vela

J Endocrinol. 2004 Oct;183(1):91-9.

PMID: 15525577

Abstract:

Several investigators have suggested that certain hydroxylated metabolites of 17beta-estradiol (E2) are the proximate carcinogens that induce mammary carcinomas in estrogen-sensitive rodent models. The studies reported here were designed to examine the carcinogenic potential of different levels of E2 and the effects of genotoxic metabolites of E2 in an in vivo model sensitive to E2-induced mammary cancer. The potential induction of mammary tumors was determined in female ACI rats subcutaneously implanted with cholesterol pellets containing E2 (1, 2, or 3 mg), or 2-hydroxyestradiol (2-OH E2), 4-hydroxyestradiol (4-OH E2), 16alpha-hydroxyestradiol (16alpha-OH E2), or 4-hydoxyestrone (4-OH E1) (equimolar to 2 mg E2). Treatment with 1, 2, or 3 mg E2 resulted in the first appearance of a mammary tumor between 12 and 17 weeks, and a 50% incidence of mammary tumors was observed at 36, 19, and 18 weeks respectively. The final cumulative mammary tumor incidence in rats treated with 1, 2, or 3 mg E2 for 36 weeks was 50%, 73%, and 100% respectively. Treatment of rats with pellets containing 2-OH E2, 4-OH E2, 16alpha-OH E2, or 4-OH E1 did not induce any detectable mammary tumors. The serum levels of E2 in rats treated with a 1 or 3 mg E2 pellet for 12 weeks was increased 2- to 6-fold above control values (approximately 30 pg/ml). Treatment of rats with E2 enhanced the hepatic microsomal metabolism of E2 to E1, but did not influence the 2- or 4-hydroxylation of E2). In summary, we observed a dose-dependent induction of mammary tumors in female ACI rats treated continuously with E2; however, under these conditions 2-OH E2, 4-OH E2, 16alpha-OH E2, and 4-OH E1 were inactive in inducing mammary tumors.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AP1261254481-B	17β-Estradiol-2,3,4-13C3		1261254-48-1	Price

As a specialist in analytical chemical Products, Alfa Chemistry offers consumers a wealth of raw materials and a full range of technologies and services.

QUICK LINKS

HEADQUARTERS

Tel:

Fax:

Email: