Exchange assays using sodium thiocyanate to measure total nuclear content of estrogen receptors in the hypothalamic pituitary axis of mice

Autor: Diego Bellabarba, Serge Belisle, Jean-Guy Lehoux
Rok vydání: 1982
Předmět:
Zdroj: Steroids. 39:643-655
ISSN: 0039-128X
DOI: 10.1016/0039-128x(82)90135-0
Popis: We studied the effect of sodium thiocyanate (NaSCN) in the determination of specific nuclear estrogen receptors from the hypothalamic-pituitary axis (HPA) of mice. We compared the results with those of the exchange assay using either suspensions of whole nuclei or KC1-nuclear extracts. Our findings demonstrated that 0.5 M NaSCN was more efficient than 0.5 M KC1 in extracting [3H] E2 nuclear content from HPA (91% vs 79.3%). Nuclear fractions extracted with 0.5 M NaSCN revealed the presence of a single class of low-capacity-high affinity binding sites that sedimented in the 4.0 S area. Nuclear binding was T degrees dependent and reached maximum levels of 450 +/- 156 (S.E.) fmol/mg DNA after an overnight incubation at 4 degrees C. Such levels were comparable to those observed in whole nuclei suspensions after 1 hour incubation at 37 degrees C (618 +/- 71 fmol/mg DNA, p greater than 0.05) but two-fold higher (p less than 0.01) than the concentration of binding sites measured in KC1-extracted nuclear fractions under similar experimental conditions. We conclude that NaSCN extracted the total content of nuclear estrogen receptors in HPA of mature mice.
Databáze: OpenAIRE