Post-conceptional induction of menses with a single vaginal suppository of (15S)-15-methyl prostaglandin F2 alpha methyl ester

The induction of post-conceptional menses needs a technically simple method which would avoid instrumentation of the uterus. One possible method investigated in this study is the abortifacient effect of a single dose long-acting vaginal suppository containing 3.0 mg of (15S)-15-methyl prostaglandin F2 alpha methyl ester. Pregnancy was terminated successfully in 13 of the 14 subjects. Two successful patients required curettage for prolonged bleeding and retained products of conception. Prolonged vaginal bleeding and the uncertainty of endpoints with particular reference to human chorionic gonadotropin (HCG) constitute the major problem with this non-invasive method, and are discussed in the light of the data obtained.     

Hormone changes occurring during second trimester abortion induced with 15 (S)-15-methyl prostaglandin F2alpha.

Changes in progesterone, human placental lactogen (HPL), cortisol and estradiol-17B were measured during second trimester abortion induced by I.M. 15-methyl PGF2alpha. A rapid decline in progesterone and HPL was found, indicating perhaps an initial effect on the placenta. A rapid rise in cortisol was found, but it is not clear if this is due to stress or part of the termination mechanism. The changes of estradiol were not as distinct and may reflect opposite effects of the prostaglandin on the placenta and adrenals. Similar hormonal changes were observed regardless of the duration of gestation.     

Termination of early gestation with a vaginal polysiloxane device impregnated with (15S)-15 methyl prostaglandin F2alpha methylester

An investigation of the abortifacient activity of (15S)-15 methyl prostaglandin F2alpha methyl ester released from a vaginal polysiloxane device was performed in eleven pregnant women of 49 days gestation or less. Bleeding and contractions were induced in all women, but only seven aborted their pregnancies. Five subjects received a vaginal device impregnated with 3 mg of drug and two aborted fetal tissue. Six women were given a vaginal device containing 5 mg of drug and five aborted fetal tissue. Ten of the patients had significant side effects, nausea, emesis, diarrhea and chills. Six women expelled the device prior to the termination of therapy. This prostaglandin analogue, when administered from a vaginal polysiloxane device in early gestation was an effective abortifacient but was accompanied by systemic side effects and a high incidence of expulsion of the device prior to its scheduled removal.     

Effect of PGF2 alpha and 15(S)-15-methyl PGE2 methyl ester on feline generalized penicillin epilepsy.

The effect of PGF2alpha and 15(S)-15-methyl PGE2 methyl ester on transient generalized epilepsy in the cat induced by penicillin was examined. Epileptic activity before and after administration of the prostaglandins by several routes was determined from continuous EEG recordings and expressed in epileptic bursts per min. The PGE2 analogue given in single non-toxic doses (1.6-3 mug/kg) by intramuscular or intravenous routes at the peak of epileptic activity significantly reduced epileptic activity for up to four hours. Subcutaneous administration was less effective. PG2alpha given by the intramuscular route (0.3 mg/kg) also markedly reduced the number of epileptic bursts. Increasing the dosage 4-fold almost completely suppressed epileptic activity. Intracarotid infusion of PGF2alpha for one hour (10 mug/min) almost abolished all epileptic activity. Neither prostaglandin given in non-toxic doses induced EEG abnormalities in non-epileptic cats. Toxic doses of the E2 analogue (greater than 16 mug/kg) caused bilaterally synchronous high voltage slow wave activity. It is concluded that these prostaglandins reduce penicillin epilepsy in the cat. The findings are consistent with either a direct excitatory action on neurones of the medial reticular formation or anatagonism of the depressant action of norepinephrine on Purkinje cells.     

Gastric antisecretory effect of 15(R)-15-menthyl PGE2, methyl ester and of 15(S)-15-methyl ester.

Gastric juice was collected from gastric pouches in dogs stimulated with histamine. 15(R)-15-methyl PGE2, methyl ester inhibited gastric secretion in dogs when given orally, but was almost inactive when given intravenously, whereas 15(S)-15-methyl PGE2 methyl ester was active by both routes. When given directly into the small intestine (intrajejunally), the 15(S) was active and the 15(R) was inactive. The 15(R), diluted in acid and administered intrajejunally, became active in inhibiting gastric secretion. When the 15(S) was diluted in acid and administered intrajejunally, it lost half of its activity. When each analog was incubated in an acid medium, each was epimerized to give approximately a 1:1 mixture of both 15(R) and 15(S). Incubation of the 15(R) in pH 3 buffer resulted in only a trace of formation of 15(S). These results explain why the 15(R) is active orally but not intrajejunally. When given orally, the low pH of gastric secretion epimerizes much of the 15(R) into the 15(S),which is active by any route. The degree of acidity of gastric contents may determine whether the 15(R) will exert an antisecretory effect.     

Gastric antisecretory actions of (15S)-15-methyl prostaglandin E2 methyl ester and natural prostaglandin E2 in rhesus monkeys

The gastric antisecretory actions of (15S)-15-methyl prostaglandin E₂ methyl ester (Me-PGE₂) and Prostaglandin E₂ (PGE₂) were evaluated in the unanesthetized gastric fistula rhesus monkey. Secretion was submaximally stimulated by multiple subcutaneous injections of histamine acid phosphate given every hour for four consecutive hours. When a steady-state plateau of gastric secretion was reached, the PG's were administered as a single bolus dose either intravenously (i.v.) or intragastrically (i.g.). Both PG's inhibited histamine-stimulated gastric secretion. The PG's showed greater sensitivity in inhibiting acid concentration while not affecting volume output. Active i.v. and i.g. antisecretory doses of Me-PGE₂ ranged from 3 to 10 μg/kg, while PGE₂ showed significant antisecretory activity at i.v. bolus doses of 30–100 μg/kg and i.g. bolus dose of 1.0 mg/kg. Thus, Me-PGE₂ is estimated to be at least 10 and 300 times more potent than PGE₂ by the i.v. and i.g. administration routes, respectively. These findings indicate that the rhesus monkey shows some similarities to man in responsiveness to gastric secretory inhibition by E-prostaglandins.     

Intramuscular prostaglandin (15S)-15-methyl PGF2α (THAM) in midtrimester abortion

Elective termination of second trimester pregnancies in 63 patients by means of intramuscular prostaglandin (15S)-15-Methyl PGF2α (THAM) is reported. In 44 of 61 cases with a successful outcome the duration of pregnancy calculated from a last normal menstrual period was between 13 and 17 weeks. An overall success rate of 96.8 percent was achieved; and this agent and method warrant further clinical evaluation.     

Termination of second trimester pregnancy with intra-amniotic 15 (S) 15 methyl prostaglandin F-2alpha - a two dose schedule study.

Termination of second trimester pregnancy with intra-amniotic administration of 15 (S) 15 methyl prostaglandin F-alpha (15 me F-alpha) was attempted in fifty patients. One group (26 patients) was given 1 mg of the analogue and the other group received 2.5 mg. The abortifacient efficacy of 15 me F-2alpha was similar in both groups; over 90% of the patients aborted with a single dose. There was a higher incidence of vomiting, diarrhoea and incomplete abortions in the group treated with 2.5 mg 15 me F-2alpha. Although the mean injection-abortion interval in the 2.5 mg group was shorter, it is concluded that intra-amniotic administration of 1 mg 15 me F-2alpha provides a better regime, giving high efficacy with a single dose, a low incidence of side effects and greater safety in case of inadvertent entry of the intra-amniotic dose into systemic circulation.     

15(S)15-methyl prostaglandin F2alpha for termination of very early human pregnancy. A comparative study of a single intramuscular injection and vaginal suppositories.

The results of a comparative study of the efficacy and acceptability of 15(S)15-methyl prostaglandin F2alpha (15-Me-PGF2alpha) administered as a single i.m. injection or vaginal suppositories (15-Me-PGF2alpha methyl ester) every 3rd hr for termination of very early human pregnancy is reported. The amenorrhoic period varied from 37 to 60 days. Group I (30 cases) received 0.6 mg as a single i.m. injection without any pretreatment. Retrospectively 24 of the 30 women were in fact pregnant and 22 of them aborted. Group II received suppositories (1.0 or 1.5 mg per suppository). In this group all women were pregnant and they all aborted. Symptoms such as pain, bleeding, vomiting and diarrhea started in general earlier in the i.m. group and they were more marked. In the present series the efficacy and acceptability were highest for the vaginal route of administration.     

Serial intramuscular injections of 15(S)-15-methyl-prostaglandin F2alpha in the induction of abortion.

Abortion was successfully induced in 62 of 68 patients in the 9th to the 26th week of pregnancy be serial intramuscular administration of 15(S)-15-methyl-prostaglandin F2alpha (15-ME-PGF2alpha). In 6 patients who failed to abort after 24 hours of prostaglandin administration, a concomitant infusion of oxytocin was initiated; 5 of these patients aborted within 12 hours of the combined therapy. A single patient failed to abort, even with the combined therapy, and underwent surgical evacuation. The mean abortion time in the 67 successful inductions was 14.56 hours. Parous patients aborted somewhat fasteter, mean 13.98 hours, as compared to nulliparous patients, mean 15.02 hours, but this difference was not statistically significant. In this study initial intramuscular injection of 100 mug 15-ME-PGF2alpha was followed in 1 hour by 250 mug and then 250 mug every 2 hours with concomitant oxytocin therapy initiated after 24 hours. The results with this dose schedule were compared to the results obtained in a previous study with a higher dose schedule, an initial dose of 100 mug 15-ME-PGF2alpha, followed in 1 hour by 250 mug then 500 mug every 2 hours. There was significant difference in the mean abortion time and the incidence of side effects between the 2 dose schedules. The mean abortion time for patients with gestational ages 16 weeks and less was the same with both dose schedules, however patients with gestational ages of 17 weeks and higher aborted somewhat faster with the higher dose schedule. It might therefore be advisable for patients with gestations of 17 weeks and higher to be treated with the higher dose schedule. In earlier gestations patients could be started on the lower schedule, and if abortion had not occurred within 15 hours the dose of 15-ME-PGF2alpha could then be increased to 500 mug every 2 hours.     

Post-conceptional induction of menses with a single vaginal suppository of (15S)-15-methyl prostaglandin F2α methyl ester

The induction of post-conceptional menses needs a technically simple method which would avoid avoid instrumentation of the uterus. One possible method investigated in this study is the abortifacient effect of a single dose long-acting vaginal suppository containing 3.0 mg of (15S)-15-methyl prostaglandin F₂α methyl ester. Pregnancy was terminated successfully in 13 of the 14 subjects. Two successful patients required curettage for prolonged bleeding and retained products of conception. Prolonged vaginal bleeding and the uncertainty of endpoints with particular reference to human chorionic gonadotropin (HCG) constitute the major problem with this non-invasive method, and are discussed in the light of the data obtained.     

Response of the midpregnant human uterus to systemic administration of 15(S)-15-methyl-prostaglandin F2alpha

The contractile response of the midpregnant human uterus to a new (PG) prostaglandin analogue, 15(S)-methyl-PGF2alpha (15-me-PGF2alpha), was investigated and compared to the effect of natural PGF2alpha. It was found that the threshold dose of 15-me-PGF2alpha was around 10 mcg when given as a single intravenous injection, which is approximately 1/10 of the corresponding dose of PGF2alpha. It was also found that higher intravenous doses of 15-me-PGFalpha resulted in a uterine response of longer duration than that following PGF2alpha. Intramuscular injection of the analogue at doses of 1.0-1.5 mg induced a marked uterine stimulation sustained for 5-7 hours without causing local reaction. Intravenous infusion of 5 mcg/min of 15-me-PGF2alpha stimulated a level of uterine activity equivalent to that of 75 mcg/min of PGF1alpha. The incidence of gastrointestinal side effects was the same in the 2 treatment groups. However, there seemed to be a tendency toward a significantly higher abortion rate with the analogue.     

Coupling between cyclooxygenases and prostaglandin F(2alpha) synthase. Detection of an inducible,glutathione-activated,membrane-bound prostaglandin F(2alpha)-synthetic activity

Distinct functional coupling between cyclooxygenases (COXs) and specific terminal prostanoid synthases leads to phase-specific production of particular prostaglandins (PGs). In this study, we examined the coupling between COX isozymes and PGF synthase (PGFS). Co-transfection of COXs with PGFS-I belonging to the aldo-keto reductase family into HEK293 cells resulted in increased production of PGF(2alpha) only when a high concentration of exogenous arachidonic acid (AA) was supplied. However, this enzyme failed to produce PGF(2alpha) from endogenous AA, even though significant increase in PGF(2alpha) production occurred in cells transfected with COX-2 alone. This poor COX/PGFS-I coupling was likely to arise from their distinct subcellular localization. Measurement of PGF(2alpha)-synthetic enzyme activity in homogenates of several cells revealed another type of PGFS activity that was membrane-bound, glutathione (GSH)-activated, and stimulus-inducible. In vivo, membrane-bound PGFS activity was elevated in the lung of lipopolysaccharide-treated mice. Taken together, our results suggest the presence of a novel, membrane-associated form of PGFS that is stimulus-inducible and is likely to be preferentially coupled with COX-2.     

Intrauterine injection of 15(S)-15-methyl-prostaglandin F2alpha for termination of early pregnancy in out-patient.

15-me-PGF2alpha was administered as single intrauterine injection for interruption of very early pregnancy in 30 out-patients. After 2 weeks, abortion was complete in 60% induced with 125 or 200 mug and 80% induced with 300 mug. After 3 weeks, abortion was complete in 90% induced with 125 mug, in 70% induced with 200 mug and in 100% induced with 300 mug. One failure occurred in patients treated with 200 mug and 2 curettages were performed because of incompleteness of abortion. No serious complications occurred. Compared with our previous results it appears that 15-me-PGF2alpha is as effective as natural PGF2alpha in inducing abortions during very early pregnancy but causes somewhat fewer side-effects.     

Induction of abortion with prostaglandin F(2)alpha in gilts and their subsequent fertility

Fourteen gilts were aborted (some of them repeatedly) by i.m. administration of 500/ug cloprostenol (PG) between 30 and 100 days of pregnancy so that the total number of PG-induced abortions was 19. Six of these gilts were allowed to terminate their subsequent pregnancy by farrowing. It was found that In a Trial under semi-production conditions the mean birth body mass of piglets from 11 gilts bred after previous PG-induced abortion was 1.48 kg as compared to 1.19 kg in the controls. The difference was significant (P<0.01).     

Canine prostaglandin F2alpha receptor (FP) and prostaglandin F2alpha synthase (PGFS): molecular cloning and expression in the corpus luteum

In the dog luteolysis is not affected by hysterectomy. This observation led to the hypothesis that paracrine/autocrine rather than endocrine mechanisms of PGF2alpha are responsible for luteal regression in the dioestric bitch. The present experiments tested for the capacity of canine CL to produce and respond to PGF2alpha by qualitatively and quantitatively determining the expressions of PGFS, the enzyme converting PGH2 into PGF2alpha, and the PGF2alpha-receptor (FP) in CL of non-pregnant dogs during dioestrus. Canine PGFS and FP were isolated and cloned; both genes show a high homology (82-94%) when compared to those of other species. Relatively weak FP mRNA expression was detected on day 5 of dioestrus. It had increased by day 25 and remained constant thereafter. In situ hybridization (ISH) localized FP solely to the cytoplasm of the luteal cells, suggesting that these cells are the only luteal targets of PGF2alpha in this species. Only negative results were obtained for the expression of PGFS in canine CL by routine qualitative RT-PCR. When Real Time (TaqMan) PCR was applied, repetitively more negative than positive results were obtained at all timepoints. Any positive measurements observed at any point were neither repeatable nor related to the stage of dioestrus. This led us to conclude that expression of PGFS is either absent or present at very low level only. These data suggest that luteal regression in non-pregnant bitches is not modulated by PGF2alpha. However, the FP seems to be constitutionally expressed, explaining the receptivity of canine CL to exogenous PGF2alpha.     

Amniotic fluid concentrations of prostaglandin F2 alpha, 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) and 11-deoxy-13,14-dihydro-15-keto-11, 16-cyclo-prostaglandin E2 (PGEM-LL) in preterm labor

Although prostaglandins (PGs) are considered the key mediators of human parturition at term, there is a paucity of data regarding their participation in the mechanisms responsible for preterm labor. The purpose of this study was to establish if preterm labor is associated with changes in the amniotic fluid concentrations of prostaglandins. PGF2 alpha, 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) and 11-deoxy-13,14-dihydro-15-keto-11,16-cyclo-prostaglandin E2 (PGEM-ll) were measured by using specific and sensitive radioimmunoassays. Amniotic fluid was retrieved by transabdominal amniocentesis from 55 women with preterm labor and intact membranes. Patients were divided into three groups according to the response to tocolysis and the presence or absence of an intra-amniotic infection. Amniotic fluid concentrations of PGFM and PGEM-ll were significantly greater in women with preterm labor and intra-amniotic infection than in women without infection. In addition, patients unresponsive to tocolysis without intra-amniotic infection also had a significantly greater concentration of PGFM and PGEM-ll in amniotic fluid than those responsive to tocolysis. Amniotic fluid concentrations of PGF2 alpha were greater in women with intra-amniotic infection than in women without intra-amniotic infection. In the absence of intra-amniotic infection, no difference in amniotic fluid PGF2 alpha concentrations could be found between women who responded to tocolytic treatment and those who did not.