Decreased myometrial beta-adrenoceptors in women receiving beta 2-adrenergic tocolytic therapy: correlation with lymphocyte beta-adrenoceptors.
We have determined simultaneously the density of beta-adrenoceptors in human myometria (by (-)-[125I]iodopindolol binding) derived from 36 women undergoing cesarean section and in the corresponding circulating lymphocytes (by (-)-[125I]iodocyanopindolol binding). In myometrial membranes about 80% to 85% of the beta-adrenoceptors were of the beta 2-subtype. The density of myometrial and lymphocyte beta-adrenoceptors in women treated with the beta 2-adrenoceptor agonist hexoprenaline to prevent preterm labor was about 65% to 70% lower than that in nontreated women. Concomitantly, in hexoprenaline-treated women the 10 mumol/L isoproterenol-evoked increase in lymphocyte cyclic adenosine monophosphate content (as index for lymphocyte beta-adrenoceptor responsiveness) was diminished to a similar extent. Combining all data resulted in a significant positive correlation between myometrial and lymphocyte beta-adrenoceptor densities (r = 0.7303; n = 36; p less than 0.001). It is possible that determination of beta-adrenoceptor function in circulating lymphocytes may be a useful model to monitor myometrial beta-adrenoceptor changes during tocolytic therapy.
Michel
M C
MC
Division of Renal and Hypertensive Diseases, University of Essen., Federal Republic of Germany.
Pingsmann
A
A
Nohlen
M
M
Siekmann
U
U
Brodde
O E
OE
D000293:Adolescent; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D005260:Female; D006594:Hexoprenaline / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D020120:Iodocyanopindolol; D008214:Lymphocytes / Q000032:analysis / Q000187:drug effects*; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000032:analysis / Q000187:drug effects*; D015149:Tocolytic Agents / Q000494:pharmacology*; D014599:Uterus / Q000032:analysis / Q000187:drug effects*
D000318:Adrenergic beta-Agonists; D007093:Imidazoles; D011943:Receptors, Adrenergic, beta; D015149:Tocolytic Agents; D020120:Iodocyanopindolol; D010869:Pindolol; C049763:CGP 20712A; D006594:Hexoprenaline