Concentration of 13,14-dihydro-15-keto-prostaglandin E2 in the maternal peripheral plasma during labour of spontaneous onset

Summary. The concentration of 13, 14-dihydro-15-keto-PGE₂ (PGEM) was measured by radioimmunoassay in pregnant women in the third trimester, in women at term but not in labour and during labour of spontaneous onset. The plasma concentration of PGEM in pregnant women was elevated above that in a non-pregnant control group. Before the onset of labour no increase of PGEM concentration could be identified. Women in labour had higher PGEM plasma concentrations than before the onset of labour, although there was no progressive increase. Immediately after delivery PGEM levels reached a maximum, which decreased significantly to pre-labour values within 30 min. Artificial rupture of the membranes had no influence on plasma PGEM levels. It is concluded that labour is associated with an increased synthesis of PGE₂ and that PGE₂ may be inved in the mechanism of placental separation. The rapid disaearance of high PGEM levels after labour confirms that PGE₂ is probably synthesized mainly in the fetal compartment.     

Primary dysmenorrhoea: the importance of both prostaglandins E2 and F2α

Summary. Menstrual fluid was collected in a contraceptive diaphragm from 16 women with primary dysmenorrhoea and 12 matched control subjects without dysmenorrhoea. Prostaglandins F_2α (PGF_2α), E₂ (PGE₂) and 6-oxo-prostaglandin F_1α (6-oxo-PGF_lα) were extracted and measured using gas-chromatography: mass spectrometry (GC:MS). The concentrations of both PGF_2α and PGE₂ were higher on days 1 and 2 in the dysmenorrhoea group than in the control group and the concentration of PGF_2α was higher on day 1 than on day 2 in the dysmenorrhoea group. The concentrations of 6-oxo-PGF_1α (the stable metabolite of PGI₂) were low in both groups. These results confirm suggestions that PGF_2α is important in the aetiology of dysmenorrhoea and also indicate that PGE₂ may be involved.     

Amniotic fluid concentrations of secreted pregnancy-associated endometrial α1 and α2-globulins (α1- and α2-PEG)

Summary. The levels of pregnancy-associated endometrial α₁- and α₂-globulins (α₁- and α₂-PEG), the two major proteins synthesized and secreted by the endometrium in vitro have been assayed in 210 amniotic fluid specimens obtained at termination of pregnancy or by amniocentesis, or at delivery. α₁-PEG was undetectable until week 10 and thereafter rose to peak levels between weeks 20 and 24. Levels fell 15-fold by week 35 but substantial amounts were still present at parturition. α₂-PEG was present at highest levels during early pregnancy, at weeks 6–15, but thereafter levels rapidly fell until during weeks 31–42 α₂-PEG was detectable in only 3 of 25 specimens. During weeks 15–20, when α₂-PEG levels fell and α₁-PEG levels rose, a high correlation was observed between the week of gestation and the log of the ratios of the concentration of these proteins. These observations provide the opportunity to assess the role of endometrial and decidual dysfunction in the aetiology of pregnancy disorders.     

Maternal plasma prostaglandin E2 metabolite levels during human pregnancy and parturition

Summary. Because of methodological problems associated with the measurement in biological fluids of both prostaglandin E₂ (PGE₂) and its unstable principal circulating metabolite 13,14-dihydro-15-keto-PGE₂ (PGEM), there is little reliable information on these prostaglandins in human pregnancy and parturition. The recent discovery of a stable PGEM degradation product 11-deoxy-13,14-dihydro-15-keto-11β, 16-cyclo-PGE₂ (bicyclo-PGEM) has provided a means of studying endogenous plasma levels of PGEM which circumvents the problems encountered with direct measurements of PGE₂ and PGEM. Using a radioimmunoassay for bicyclo-PGEM we have therefore determined maternal peripheral plasma PGE₂ metabolite levels during human gestation. PGE₂ metabolite levels did not alter significantly during the second or third trimesters nor during labour. This contrasts with maternal peripheral plasma levels of the principal circulating metabolite of PGF_2α 13,14-dihydro-15-keto-PGF_2α (PGFM) which increases several fold during labour. Compared t o PGE₂ therefore. PGF_2α may be quantitatively the more significant prostaglandin associated with human parturition.     

Termination of Pregnancy by Intra-uterine Prostaglandin F2α

Summary: Fourteen pregnancies between the 12th and 19th weeks of gestation were terminated by intra-uterine administration of prostaglandin F_2α. In 7 patients the method of administration was transcervically into the extra-ovular space; in the other 7, administration was directly into the amniotic sac. The methods of administration, the doses used, the side effects and results are discussed. The findings indicate that intra-amniotic administration is the procedure of choice: firstly, because of the incidence of genital tract infection after transcervical administration; secondly, because 3 patients in the transcervical group had incomplete abortions and required anaesthesia for curettage; and finally, the induction-abortion interval was significantly less when the drug was administered into the uterine cavity.     

Complex formation of pregnancy-specific α2–glycoprotein (SP1α) and heparin

Summary. The Schwangerschaftsprotein 1 (SP₁,)α values in blood measured by rocket immunoelectrophoresis are affected by the addition of anticoagulants. When compared with values in serum, those in heparin plasma were much higher, while those in sequestrene ethylenediaminetetra acetic acid), sodium citrate and fluoride oxalate were lower. On the other hand, SP₁ and SP₁β concentrations were not significantly affected in heparin or sequestrene and were only slightly depressed in sodium citrate and flouride oxalate. The effect of heparin on SP₁α in serum was dosedependent. We surmise that SP₁α forms a complex with heparin and that it may be involved in the coagulation system in pregnancy.     

The use of 16,16-dimethyl-transδ2 prostaglandin E1 methyl ester (gemeprost) vaginal pessaries for the termination of pregnancy in the early second trimester. A comparison with extra-amniotic prostaglandin E2

Summary. The use of gemeprost pessaries has been compared in an open randomized trial with the extra-amniotic infusion of prostaglandin E₂ (PGE₂) for the termination of pregnancy between 12 and 16 weeks gestation. The success rates were 77% and 79% for the pessary and infusion group respectively, and these rates were unaffected by parity. There was no significant difference in the cumulative abortion rate between the two groups, nor were there differences in the induction-abortion interval, nor in the time taken to the onset of pain or bleeding. However, women in the pessary group required significantly less analgesia than those in the infusion group. Side-effects, experienced both during treatment and during the 6 weeks after abortion, were similar in both groups. Gemeprost vaginal pessaries are an effective alternative to the extra-amniotic infusion of PGE, for the termination of pregnancy in the early second trimester.     

Immunohistological localization of pregnancyassociated endometrial α2-globulin (α2-PEG) in endometrial adenocarcinoma and effect of medroxyprogesterone acetate

Summary. Endometrium from postmenopausal women with endometrial adenocarcinoma was examined immunohistochemically using a monoclonal antibody to pregnancy-associated endometrial α₂-globulin (α₂-PEG), the major secretory protein of the glandular epithelium during the late luteal phase of the menstrual cycle and early pregnancy. Specimens were obtained at initial diagnostic curettage and at hysterectomy after medroxyprogesterone acetate (MPA) therapy. α₂-PEG was not detected in any malignant tissue irrespective of histological differentiation. Non-malignant endometrium obtained in association with malignant tissue was negative for α₂-PEG before treatment although after MPA therapy all specimens obtained exhibited marked α₂-PEG localization in glands. In four specimens endogenous alkaline phosphatase was observed consistently only in the malignant endometrium. Malignant endometrium does not appear to synthesize α₂-PEG nor is its synthesis induced by an oral progestogen, so that it does not represent a useful marker for endometrial carcinoma. Non-malignant endometrium in postmenopausal women appears to be fully capable of α₂-PEG production after stimulation with an oral progestogen.