The effect of the release of exogenous nitric oxide on the responses of the pregnant human myometrium to oxytocin.

Objective: Introduction: Currently there is insufficient evidence to support the routine administration of nitric oxide donors in the treatment of threatened preterm labor. An understanding of the role that nitric oxide plays in the management of threatened preterm labor may lead to more effective treatment and prevention. The aim of our study was to examine the involvement of exogenous nitric oxide release in regulating responses of the human pregnant myometrium to oxytocin.

The sources of calcium for noradrenaline-induced contraction in the human thoracic internal artery.

The aim of the present study was to examine the contribution of intracellular and extracellular calcium sources in contraction caused by noradrenaline (NA) of the human internal thoracic artery (ITA) in vitro. Distal segments of ITA were obtained from 20 patients (aged 38-73, at the time of routine coronary artery surgical revascularization (CABG)). Contractile responses to 10 mol/L NA in the physiological salt solution and in Ca-free solution without and after incubation with 10 mol/L thapsigargin (TSG) were recorded under isometric conditions.

Altered uterine contractility in response to β-adrenoceptor agonists in ovarian cancer.

We aimed to prospectively examine β-adrenoceptor-mediated uterine contractility in women suffering from gynecological malignancies. Myometrial specimens were obtained from non-pregnant women undergoing hysterectomy for benign gynecological disorders, and ovarian, endometrial, synchronous ovarian-endometrial, and cervical cancer. Contractions of myometrial strips in an organ bath before and after cumulative dosages of β- and β-adrenoceptor agonists with preincubation of propranolol, SR 59230A, and butoxamine were studied.

Cu(II) complexation does not affect oxytocin action on pregnant human myometrium in vitro.

Objective: Copper may influence the in vivo and in vitro uterine activity. Recent evidence shows that cupric ions can easily form complexes with oligopeptides like oxytocin (OXT). The high complex stability in vitro suggests a possibility of complex formation in vivo.

Differences in the effects of beta2- and beta3-adrenoceptor agonists on spontaneous contractions of human nonpregnant myometrium.

Objective: This study aimed to compare the relaxant properties of BRL 37344 with p2-adrenoceptors agonist ritodrine on the contractility of human nonpregnant myometrium.

Material And Methods: The activity of myometrial strips mounted in an organ bath was recorded under isometric conditions using force transducers with digital output. Contractility before and after cumulative additions of both uterorelaxants and with preincubation with beta-adrenoceptor antagonists bupranolol, propranolol, and butoxamine were studied.