title: [The effect of the beta 1-blocker metoprolol on cyclic 3',5'-adenosine monophosphate in various tissues during long-term tocolysis with fenoterol. Animal experiments on the question of the interactive effects of the principal and adverse effects of beta 2-mimetics with special regard to fetal cardioprotection].
abstract: Using pregnant Wistar rats a comparative study was carried out, which was aimed to investigate the effect of long-term tocolysis (second half of gestation) with fenoterol alone as well as in combination with the cardioselective beta-blocker metoprolol (Beloc) upon the level of beta-adrenoceptor stimulation in maternal pulmonal, myocardial and myometrial tissue and in the myocardium of the fetuses. Radioimmunologic assessment of cyclic AMP tissue concentrations was used to obtain a parameter for beta-adrenoceptor stimulation. During treatment with fenoterol alone a significant rise of cyclic-AMP could be observed in all tissues, fetal myocardium showing the most pronounced rise. When combining fenoterol and metoprolol no derangement of the desired therapeutical beta 2-effect upon myometrium and lung could be found. Cyclic-AMP concentration in the maternal myocardium, however, was reduced significantly after combination therapy as compared to the monotherapy group, stressing the cardioprotective effect of metoprolol during beta 2-mimetic therapy, which yet has been demonstrated by means of other experimental models. As a similar tendency could be found in fetal myocardium, the conclusion may be drawn that combining metoprolol with fenoterol exerts also a fetal cardioprotection during beta 2-mimetic therapy of pregnant individuals. Furthermore possible effects of this combined therapy upon fetal beta-adrenergic reactions in general are discussed in this study.
mesh_terms: D000318:Adrenergic beta-Agonists / Q000009:adverse effects / Q000627:therapeutic use*; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D004359:Drug Therapy, Combination; D005260:Female; D005280:Fenoterol / Q000627:therapeutic use; D005333:Fetus / Q000187:drug effects*; D006331:Heart Diseases / Q000517:prevention & control*; D008168:Lung / Q000378:metabolism; D008790:Metoprolol / Q000494:pharmacology*; D009206:Myocardium / Q000378:metabolism; D007752:Obstetric Labor, Premature / Q000378:metabolism / Q000517:prevention & control*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D014599:Uterus / Q000378:metabolism
chemical_list: D000318:Adrenergic beta-Agonists; D005280:Fenoterol; D000242:Cyclic AMP; D008790:Metoprolol
vernacular_title: Zum Einfluss des beta 1-Blockers Metoprolol auf das zyklische 3',5'-Adenosinmonophosphat in verschiedenen Gewebsarten unter Langzeittokolyse mit Fenoterol. Tierexperimentelle Untersuchungen zur Frage interaktiver Effekte bei Haupt- und Nebenwirkungen von beta 2-Mimetika unter besonderer Berücksichtigung der fetalen Kardioprotektion.