Hepatic estrogen-binding proteins in male and female vervet monkeys.
Hepatic cytosols from male and female vervet monkeys (Cercopithecus pygerythrus) were found to contain the same levels of high affinity estrogen-binding proteins. Multipoint saturation analyses revealed that male liver cytosols contain two distinctly different binding components: a high affinity (HAEB) and a low affinity estrogen binder (LAEB). Female livers appeared to contain only the HAEB. Sucrose density gradient (SDG) analyses, however, clearly established the presence of a 3.8 S as well as an 8.1 S estrogen-binding component in the hepatic cytosols of both sexes. The 3.8 S binding component appeared to be more prominent in male SDG profiles. Cytosols, prepared in the presence of sodium molybdate (cyt +) exhibited significantly lower (50%) levels of specific estrogen-binding than cytosols prepared in the absence of the oxyanion (cyt-). SDG analyses, however, indicated that in cyt+ the 8.1 S binding component was stabilized at the cost of the 3.8 S binder. This phenomenon was observed in both sexes. Large excess levels of cortisol did not have any effect on specific estrogen binding by hepatic cytosols. The hepatic estrogen-binding proteins displayed a lower relative binding affinity for diethylstilbestrol than for its native ligand and higher affinities for estriol and estrone than expected.
AEC Institute of Life Sciences, University of Pretoria, South Africa.
L
L
Bornman
H C
HC
Potgieter
N
N
Savage
D000818:Animals; D001667:Binding, Competitive; D002499:Centrifugation, Density Gradient; D002521:Cercopithecus; D003600:Cytosol / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D011960:Receptors, Estrogen / Q000302:isolation & purification / Q000378:metabolism*; D012737:Sex Factors
D011960:Receptors, Estrogen; D004958:Estradiol