Identification of prolactin receptors in hepatic nuclei.
Prolactin is a trophic hormone which may act directly at the hepatocyte nucleus. In this study, specific prolactin binding sites were sought in purified rat liver nuclei. Saturable and specific, high affinity 125I-prolactin binding sites were demonstrated to be on or within the nucleus. Prolactin binding was competitively inhibited by rat and ovine prolactins but not by rat growth hormone. Using immunogold electron microscopy, we detected prolactin receptors throughout the nucleus, in association with heterochromatin. Furthermore, endogenous immunoreactive prolactin was demonstrated to be within hepatic nuclei. We conclude that rat liver nuclei possess prolactin binding sites which likely participate in hormone-directed growth processes.
Buckley
A R
AR
Department of Pharmacology, University of North Dakota School of Medicine, Grand Forks 58203.
Montgomery
D W
DW
Hendrix
M J
MJ
Zukoski
C F
CF
Putnam
C W
CW
D000818:Animals; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D003600:Cytosol / Q000378:metabolism; D007457:Iodine Radioisotopes; D007700:Kinetics; D008027:Light; D008099:Liver / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D011388:Prolactin / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011981:Receptors, Prolactin / Q000378:metabolism*; D012542:Scattering, Radiation
D007457:Iodine Radioisotopes; D011981:Receptors, Prolactin; D011388:Prolactin