[The effect of methergoline and of a synthetic estrogen on plasmatic prolactin levels and on postpartum lactation]. / Effetto della metergolina e di un estrogeno di sintesi sui livelli di prolattina plasmatica e sulla montata lattea nel post-partum.

PIP: 30 women who, for various reasons, did not wish to breastfeed were treated with 12 mg of methergoline a day, for 5 days, while a second group of women were treated, for the same purpose, with 450 mg of resorcilic acid lactone for 5 days. In the first group not only lactation was totally suppressed, but plasma prolactin levels were significantly reduced. In the second group lactation was inhibited, but prolactin levels remained the same.^ieng

Binding characteristics of zearalenone analogs to estrogen receptors.

The estrogenic effect of zearalenone derivatives was investigated for their binding characteristics to cytosol and nuclear receptors in the uterus. Competition with 17beta-estradiol at the cytosol receptor sites was observed in four of the six derivatives tested, namely trans- and cis-zearalenone, zearalenol, and zearalanol. The other two, 8'-hydroxyzearalenone and 6'-aminozearalene, lacked the binding ability to receptors and were biologically inactive. trans-Zearalenone, like 17beta-estradiol, could elicit an immediate translocation of cytosol-receptor complexes into the uterine nuclei. However, it differs from either 17beta-estradiol or antiestrogens (tamoxifen) in three aspects: (a) a second wave of translocation occurred 6 to 12 hr following zearalenone injection; (b) there was a much longer nuclear retention (over 24 hr) than in the case of 17beta-estradiol; and (c) following a depletion of cytosol receptors, trans-zearalenone induced an overreplenishment by 24 hr, whereas tamoxifen is reported to suppress the replenishment.

Comparison of the effects of (--)-isoprenaline, orciprenaline terbutaline, and Me506 on heart rate, soleus muscle contractility and pulmonary resistance of anaesthetized cats.

1. Three resorcinol derivatives with N-isopropyl (orciprenaline), N-t-butyl (terbutaline) and N-p-hydroxypheny-t-butyl (Me506) amine substituents have been compared with (--)-isoprenaline for their ability to produce beta-receptor mediated reductions in serotonin-induced increases in pulmonary resistance, decreases in soleus muscle contractility and increases in heart rate in anaesthetized cats. 2. For all parameters studied the four compounds produced similar maximal responses and dose-response curves were close to parallel. From the graphs doses of the compounds producing 50% of the maximal response (ED50) were interpolated, and from these dose-ratios with respect to (--)-isoprenaline [drug ED50:(--)-isoprenaline ED50] were calculated on a molar basis. 3. Increasing the size of the amine substituent from N-isopropyl to N-t-butyl led to an increase in beta-receptor stimulant activity in bronchial and skeletal muscle, but not in the heart. The change from N-t-butyl to N-p-hydroxyphenyl-t-butyl did not further affect stimulant activity in any of the parameters studied. 4. Calculation of selectivity ratios [molar dose-ratio (heart): molar dose-ratio (pulmonary resistance)] showed that orciprenaline was non-selective, and that terbutaline and Me506 showed a similar degree of selectivity for beta2- as opposed to beta1-receptor mediated actions.

Curvularin from penicillium baradicum Baghdadi NRRL 3754, and biological effects.

Curvularin, a fungal metabolite similar in chemical structure to zearalenone, a potent estrogen, was tested for its estrogenic effects to gilts. No estrogenicity was observed to 60 kg gilts after feeding curvularin per os at a rate of 10 mg per day for 5 days. Curvularin was also nontoxic to mice and chick embryo.