Up-regulation of guinea pig myometrial beta-adrenergic receptors by intrauterine estradiol and progesterone pellets.
The effect of intrauterine implantation of 17 beta-estradiol and progesterone on the concentration and affinity of myometrial beta-adrenergic receptor were studied in nonpregnant, previously oophorectomized guinea pigs receiving intrauterine implants of either 17 beta-estradiol, progesterone, a combination of the two hormones, or placebo for 7 days. Myometrial beta-adrenergic receptors were characterized by use of (-)-iodine 125-cyanopindolol as the specific beta-adrenergic receptor ligand. On comparison with the control group, administration of 17 beta-estradiol or progesterone resulted in a severalfold increase in the concentration (Bmax) of myometrial beta-adrenergic receptor and a lesser but significant increase in the dissociation constant, KD. Although a combination of 17 beta-estradiol and progesterone treatment increased the concentration and the dissociation constant of beta-adrenergic receptors, it did not result in any synergistic or additive effect. We conclude that intrauterine administration of these sex steroid hormones, directly or indirectly, modulates myometrial beta-adrenergic receptor concentrations and affinity.
Hatjis
C G
CG
Department of Obstetrics and Gynecology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina.
Koritnik
D R
DR
Grogan
D M
DM
D000818:Animals; D004343:Drug Implants; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D009215:Myometrium / Q000378:metabolism*; D009994:Osmolar Concentration; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011374:Progesterone / Q000097:blood / Q000494:pharmacology*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D014599:Uterus
D004343:Drug Implants; D011943:Receptors, Adrenergic, beta; D011374:Progesterone; C047975:cyanopindolol; D004958:Estradiol; D010869:Pindolol