Cytosol estrogen receptors

Estradiol. The first neuroactive steroid receptor type to be recognized was that for estradiol [3]. In vivo uptake of [3H] estradiol, and binding to cell nuclei isolated from hypothalamus, pituitary and other brain regions, revealed steroid specificity closely resembling that of the uterus, where steroid receptors were first discovered [3]. Cytosolic estrogen receptors isolated from pituitary and brain tissue closely resemble those found in uterus and mammary tissue. A hallmark of the estrogen receptor is its existence... 

In vivo studies in animals suggest that endosulfan may disrupt normal reproductive hormone levels in male animals, but that it is not an endocrine disrupter in females. Persistent depressed testicular testosterone was seen in male rats after intermediate duration oral exposures to endosulfan. In ovariectomized female rats, orally administered endosulfan did not induce normal development of female reproductive tissues, and in female mice and immature female rats, acute parenteral exposure to endosulfan did not affect several endocrine-related end points. In vitro studies have evaluated endosulfan for estrogen receptor (ER) and cytosolic protein binding affinity, ER-mediated reporter gene expression, estrogenic induction of cell proliferation, and alteration of relative abundance of active estradiol metabolites. Overall, in vitro evidence in favor of endosulfan estrogenicity indicates relatively weak potency compared to 17[3-estradiol. Apparently contradictory results were reported in different... 

Navarro D, Ledn L, Chirino R, Fernandez L, Pestano J, Dlaz-Chico BN (1998) The two native estrogen receptor forms of 8S and 4S present in cytosol from human uterine tissues display opposite reactivity with tamoxifen aziridine and the estrogen response element. J Steroid Biochem Mol Biol 64 49... 

Meyers CY, Kolb VM, Gass GH, et al. 1988. Doisynolic-type acids - uterotropically potent estrogens which compete poorly with estradiol for cytosolic estradiol receptors. J Steroid Biochem 31 (4A) 393-404. 

Rat uterine cytosol or alpha isoform of the human recombinant estrogen receptor... 

The estrogen receptor affinity of EM-652, the active drug of EM-800, was first measured in human breast cancer and normal human uterine cytosol (Asselin et al., 1980). As measured by competition studies in human breast cancer tissue, the affinity of EM-652 (Aj = 0.047 0.003 nM, RBA = 291, relative to 17p -estradiol set at 100), studied in the presence of... 

Thorpe SM. Immunological quantitation of nuclear receptors in human breast cancer Relation to cytosolic estrogen and progesterone receptors. Cancer Res 1987 47(7) 1830-1835. 

Due to the failure to respond of approximately 40% of patients who were positive for cytosolic ERP and the response of 10% of patients who were negative to ERP (C4, H4), it was accepted that if the results were accompanied by PRP the predictive value would increase (Dl). Another attempt to improve the predictive value of cytosolic ERP was the measurement of nuclear estrogen receptors in addition to the cytosolic ERP (LI). It was found that mixed combinations, whether cytosolic ERP+ nuclear- or cytosolic ERP- nuclear+, correlated with response rates of only 24 and 11%, respectively. 

L5. Loven, D., Rakowsky, E., Geier, A., Lunenfeld, B., Rubinstein, A., Klein, B., and Lurie, H., A clinical evaluation of nuclear estrogen receptors combined with cytosolic estrogen and progesterone receptors in breast cancer. Cancer (Philadelphia) 66, 341-346 (1990). 

Mobbs, B. G., and Johnson, 1. E., Use of an enzymeimmunoassay (EIA) for quantitation of cytosolic and nuclear estrogen receptor and correlation with progesterone receptor in human breast cancer. J. Steroid Biochem. 28, 653-662 (1987). 

Anderson KM, Pheian J, Marogil M, Hendrickson C and Economou S (1980) Sodium molybdate increases the amount of progesterone and estrogen receptor detected in certain human breast cancer cytosols. Steroids 35 273-280. 

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