Beta-adrenergic receptor concentration and subtype in the corpus luteum of the adult pseudopregnant rat.
Luteal beta-adrenergic receptor concentration and subtype were determined in adult pseudopregnant rats during and after the period of the functional luteal phase. The specific beta-adrenergic receptor ligand (-)-3-[125I]iodocyanopindolol ([125I]ICYP) was used to determine the receptor concentration in corpora lutea of adult pseudopregnant rats. A 3-fold increase in beta-adrenergic receptor concentration was seen during the first 2-3 days of pseudopregnancy, whereafter the receptor concentration declined. During the functional luteal regression period (Day 12-15) the receptor levels were still low. In regressed (Day 16-22) corpora lutea a temporary increase in beta-receptor concentration was seen which may represent some role for beta-adrenergic mechanisms in the regulation of morphological regression in the corpus luteum. To determine the beta-adrenergic subtype, competition of [125I]ICYP-binding with selective beta 1- and beta 2-adrenergic antagonists was assessed in corpora lutea of different ages and in rat heart and uterus. The beta-adrenergic receptors in corpora lutea of adult pseudopregnant rats were shown to be solely of the subtype beta 2, regardless of the luteal age.
Norjavaara
E
E
Department of Physiology, University of Göteborg, Sweden.
Rosberg
S
S
Gåfvels
M
M
Boberg
B M
BM
Selstam
G
G
D000818:Animals; D003338:Corpus Luteum / Q000032:analysis*; D005260:Female; D008183:Luteal Phase; D011555:Pseudopregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000032:analysis*
D011943:Receptors, Adrenergic, beta