title: Up-regulation of guinea pig myometrial beta-adrenoreceptors by systemic estradiol and progesterone.
abstract: The effects of systemic administration of 17 beta-estradiol (E2) and progesterone (P) on the concentration and affinity of myometrial beta-adrenoreceptors were studied in non-pregnant, previously oophorectomized guinea pigs receiving a continuous infusion of E2, P, a combination of the two hormones, or placebo for 7 days. Myometrial beta-adrenoreceptors were characterized by using (-)-[125I-cyanopindolol as the specific beta-adrenoreceptor ligand. Compared to that in the control group, E2 administration resulted in a 7-fold increase in the density of myometrial beta-adrenoreceptors. Administration of P alone resulted in a significant increase in both beta-adrenergic receptor concentration and the receptor dissociation constant (Kd). Finally, a combination of E2 and P treatment did not result in any synergistic or additive effect for the beta-adrenergic receptors, while the Kd was twice that of the control or E2-treated animals. We conclude that systemic administration of these sex steroid hormones, directly or indirectly, modulates myometrial beta-adrenergic receptor concentrations and their ligand affinity.
authors.affiliation: Department of Obstetrics and Gynecology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina 27103.
authors.forename: C G
authors.initials: CG
authors.lastname: Hatjis
authors.forename: D R
authors.initials: DR
authors.lastname: Koritnik
authors.forename: A
authors.initials: A
authors.lastname: Crews
mesh_terms: D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D020120:Iodocyanopindolol; D007700:Kinetics; D009215:Myometrium / Q000378:metabolism*; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011374:Progesterone / Q000494:pharmacology*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
chemical_list: D011943:Receptors, Adrenergic, beta; D011374:Progesterone; D004958:Estradiol; D020120:Iodocyanopindolol; D010869:Pindolol