title: Exchange assays using sodium thiocyanate to measure total nuclear content of estrogen receptors in the hypothalamic pituitary axis of mice.
abstract: 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.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000032:analysis; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000032:analysis*; D008722:Methods; D051379:Mice; D008810:Mice, Inbred C57BL; D011960:Receptors, Estrogen / Q000032:analysis*; D013861:Thiocyanates
chemical_list: D011960:Receptors, Estrogen; D013861:Thiocyanates; C024553:sodium thiocyanate