Gestagen treatment enhances the tocolytic effect of salmeterol in hormone-induced preterm labor in the rat in vivo.
OBJECTIVE
The purpose of this study was to determine whether gestagen treatment enhances the effects of beta2-mimetics in hormone-induced preterm delivery in pregnant rats in vivo.


METHODS
Preterm birth was induced with a combination of mifepristone and prostaglandin E2 on day 19 of pregnancy. The animals were treated with salmeterol or gestagens (progesterone or 17alpha-hydroxyprogesterone) or their combination. The treatments were launched on different days (15-18) of pregnancy. The efficacy of treatment was determined in terms of the delivery time counted from the mifepristone injection.


RESULTS
Salmeterol treatment delayed premature labor by 2.4 hours, whereas the delay because of the gestagen-salmeterol combinations was more than 5 hours. Progesterone had no effect on the delivery time.


CONCLUSIONS
Parallel treatment with salmeterol and gestagens can be more than twice as effective as salmeterol therapy alone. These results open up a possibility for human trials of combined beta2-agonist-gestagen therapy in threatening preterm delivery.
Gálik
Márta
M
Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, Szeged, Hungary.
Gáspár
Róbert
R
Kolarovszki-Sipiczki
Zoltán
Z
Falkay
George
G
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000420:Albuterol / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000818:Animals; D015232:Dinoprostone / Q000008:administration & dosage; D005260:Female; D015735:Mifepristone / Q000008:administration & dosage; D007752:Obstetric Labor, Premature / Q000139:chemically induced / Q000517:prevention & control*; D011247:Pregnancy; D011372:Progestins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000068299:Salmeterol Xinafoate; D015145:Tocolysis
D000318:Adrenergic beta-Agonists; D011372:Progestins; D015735:Mifepristone; D000068299:Salmeterol Xinafoate; D015232:Dinoprostone; D000420:Albuterol