Estradiol binding components in intestinal mucosa of female rats.
The presence of estrogen binding components (EBC) in intestinal mucosa of female rats was investigated by competitive-binding assay using radiolabelled and nonlabelled estradiol 17 beta (E2). EBC were found exclusively in the nuclear fraction and were absent from the cytosolic and from the microsomal fractions. Two types of nuclear EBC with different binding characteristics and capacities were found: Kd1 = 4.8 +/- 0.8 nM, n1 = 18.4 +/- 4.2 fmol/mg protein (n1 = 83.4 +/- 12.5 fmol/mg DNA) and Kd2 = 31.1 +/- 6.8 nM, n2 = 91.1 +/- 18.5 fmol/mg protein (412.7 +/- 80.0 fmol/mg DNA). Type 1 component showed slightly greater affinity for estrogens as compared to progesterone and dexamethasone whereas type 2 component bound other competitors with even greater affinity than E2.
Lenasi
H
H
Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Yugoslavia.
Breskvar
K
K
Hudnik-Plevnik
T
T
D000818:Animals; D001667:Binding, Competitive; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004958:Estradiol