Assays estrogen assay

ODUM J, LEFEVRE P A, TITTENSOR S, PATON D, ROUTLEDGE E J, BERESFORD N A, SUMPTER J p and ashby j, The rodent uterotrophic assay critical protocol features, studies with nonyl phenols, and comparison with a yeast estrogenic assay , Regul Toxic Pharmacol 1997 25 176-88. 

A 24-analog hydroxystilbene library 34 was constructed from the Horner-Emmons olefination of four resin-bound hydroxybenzaldehyde BBs 33 and six different benzyl phosphonate anions [32], Screening for activity in a cell-based estrogenic assay identified several analogs such as 35 with IC50 values in the 5-15 pM range. 

Major incubation volumes were prepared for each of the estrogen assays, and from each incubate 600-/xl samples were applied onto 20 minicolumns that were centrifuged together. Table VI reports the values that were measured with coefficients of variation between 2.5% and 5.4%. 

P3. Paulsen, C. A., ed., Estrogen Assays in Clinical Medicine. Univ. of Washington Press, Seattle, Washington, 1965. 

Androgenic activity is most commonly assessed in castrated, immature male rats. For hormonal assay some investigators have preferred to use random bred animals rather than homozygous animals. Some years ago Emmens (20) made an excellent case for use of random bred mice for estrogen assays. Despite this, I prefer to use homozygous animals whenever possible. This animal variable can be standardized, and our own experience with homozygous animals bred in our laboratory has been much more salutary than our experience with the random bred animals that we have purchased. 

Fig, 2. Ouchterlony radial immunodiffusion assay of sera and tissues from intact and estrogen-treated female sirtalis. Center well assay A rabbit 337 anti-vitellogenin. Center well assay B vitellogenin, 100 mg/ml. Wells 1 and 4 both assays estrogen-treated female serum. Well 2 both assays untreated female serum. Well 3 both assays dermal tissue from untreated female. Well 5 both assays dermal tissue from untreated female, treated in vitro with estradiol in PBS. Well 6 both assays dermal tissue from the same untreated female as the serum in well 2 and the tissue in well 5, treated as in well 5 but without estradion. Drawn from a plate in Garstka 0-982). 

In assay sytems, many of these phytoestrogens are able to bind more avidly to the estrogen receptor than estrogen itself. Why plant products should possess such avid estrogenic compounds is unclear, but it has been suggested that consumption of phytoestrogens by insects may result in alterations in the sex... 

The measurement of ER has become a standard assay in the clinical management of breast cancer. The presence of ERa identifies those breast cancer patients with a lower risk of relapse and better clinical outcome. Receptor status also provides a guideline for those tumors that may be responsive to hormonal intervention. But only about half of ER-positive patients respond to hormonal therapies. Of those who respond initially, most will eventually develop an estrogen unresponsive disease following a period of treatment even though ERa is often still present. Mutant receptors and constitutively active r eceptors as well as hormone-independent activation of the ERa are discussed. The involvement of ER 3 isoforms is under investigation. 

Soto AM, Sonnenschein C, Chung KL, et al. 1995. The E-SCREEN assay as a tool to identify estrogens An update on estrogenic environmental pollutants. Environ Health Perspect 103 (Supp. 

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