The efficacy of the extraovular “Prostaglandin-Impact” in provoking first trimester abortion

In good agreement with earlier findings (1–8) legal abortion had been induced successfully with Csapo's method of “Prostaglandin Impact” (PGI) in 44 out of 50 sedated patients. They were 25±1.1 years of age, 11.3±0.2 weeks pregnant, para 1.1±0.2. Only a PGI (10 mg PG F2α) was delivered into the extraovular space. In 44 women, this single PGI provoked 40% progesterone (P)-withdrawal in 3 hours (P < 0.001) and 64% P-withdrawal (P < 0.001) in 15.3±0.9 hours, when the patients aborted. The remaining 6 women, whose P-withdrawal was only 14% at 3 hours without continuation during 24 hours, failed to abort. Thus in PG-induced abortions the regulatory significance of rapid and continued P-withdrawal (1–8) had been verified.The side effects were mild, transient and acceptable. The “Abortion Score” was 86. There were no serious complaints or complications during the study and followup. Since even in the 6 cases of failure the cervix dilated sufficiently to allow curettage (without surgical dilatation), the therapeutic benefits of the single PGI technique should be further examined in those services, where constant medical supervision (for determining the necessity and timing of repeated PGI) is not available.     

The effect of uterine stretch on first trimester abortions induced by extraovular prostaglandin impact

In 20 obstetrically normal 1st trimester pregnant volunteers abortion had been induced successfully in 19, by Prostaglandin-Impact (PGI) technique (1). A total average dose of 12.3±0.9 mg PG F2α, delivered into the extraovular (E.O.) space, reduced the plasma P levels from an initial value of 29.4±2.5 ng/ml to 12.8±1.6 ng/ml (P < 0.001) within 17.4±1.6 hours instillation-abortion time (IAT). Of the 20 women 13 aborted completely, 6 incompletely, and 1 progressed to 2 cm cervical dilatation: yielding an “Abortion Score” (AbS) of 86.0±4.6.Of the 20 gravidas, 10 only received PGI (Control Group), while the remaining 10 were exposed to uterine stretch, in addition to PGI (Experimental Group). Stretch had been accomplished by a “stretch balloon” filled with 200 ml saline. Comparing the Control and Experimental Groups revealed that stretch shortens the IAT and improves the AbS. This effect is very probably achieved through a stretch induced increase in the endogenous PG-synthesis of the uterus (1). This preliminary finding exposes the possibility, that pregnancy termination can be promoted by an increased involvement of endogenous PGs in the activation of the myometrium, provoked through stretch. The validity of this premise is under current examination.     

The termination of first trimester pregnancy by extraovular “Prostaglandin-impact”

In 30 sedated volunteers first trimester pregnancy had been successfully terminated with Csapo's method of “Prostaglandin-Impact” (1). The patients were 24.1±0.4 years of age, 9.2±0.4 weeks pregnant, para 0.4±0.1. They all received an extraovular dose of 10 mg PG F2α, under intravenous sedation (100 mg pethidium hydrochloride, 50 mg DPP hydrochloride and 0.5 mg atropinum sulfate). Those 15 (out of 30) patients, whose clinical progress was slow received at 8 hours after the first PG Impact (PGI) a 2nd dose of 5 mg PG F2α, increasing the total average dose to 12.5± 0.5 mg.PGI invariably provoked a rapid and high level uterine contracture. At 4 hours after PGI plasma progesterone (P) already decreased by 20% and cyclic intrauterine pressure was in distinct evolution. At 8 hours after PGI, 15 of the 30 patients showed advanced clinical progress and 33% decrease in P levels. These women aborted in 10.2±1.1 hours, when their P levels decreased by 45% (P < 0.001). Abortion was complete in 13 and incomplete in 2 of the patients. The remaining 15 women, whose clinical progress was indistinct at 8 hours after PGI and whose P levels only decreased by 25% received a 2nd dose of 5 mg PG F2α. These women aborted after 18.5±1.5 hours, 9 completely and 6 incompletely, when their P levels decreased (as in the previous group) by 45% (P < 0.001).All the 30 patients aborted after a short IAT of 14.3±1.2 hours. Abortion was complete in 22 women, while 8 retained various amounts of placental tissue. The “Abortion Score” was high, 94.7±1.6. Only 13 patients had side effects, shortly after PGI, manifesting in vomiting and nausea, which were transient and mild. There were no complications during the study and followup. These findings confirm earlier results (1). When supplemented by extensive field trials, the technique of extraovular PGI might be broadly considered for the non-surgical termination of 1st trimester pregnancy.     

Pregnancy termination with the PGE2-analogue SHB 286

A group of 94 volunteers were treated with PGE₂-analogue SHB 286 at the 12±1 week of pregnancy. Of the 94 gravidas, 78 received a single extraovular dose of 50–200μg (Mean±S.E. 76±7μg) while 16 a short intravenous infusion of 1000–200μg SHB 286. Despite the single treatment and low dose, the success rate was 69% and the instillation-abortion time only 15±1 hours. At 24 hours after treatment even those gravidas who failed to abort (31%) had sufficient cervical dilatation for curettage and thus could be spared from rapid surgical dilatation.Peripheral plasma progesterone and estradiol-17β decreased significantly at 4 hours after treatment in those gravidas who subsequently aborted. After an initial contracture response of the uterus to SHB 286, the cyclic intrauterine pressure evolved gradually. In 4 hours it reached significantly higher levels in those gravidas who subsequently aborted than in those who did not.     

Decrease of utero-placental blood flow during prostaglandin F2α induced abortion

Pregnancy had been terminated in 6 normal midtrimester pregnant patients by the extraovular injection of 10 mg prostaglandin F2α (PGF2α). In these 6 Experimental and 3 Control patients utero-placental blood flow had been measured, by changes in the density of radioactive Indium, distributed over the uterine area, as a function of time. In comparison with Controls utero-placental blood flow decreased in the Experimental patients already at 5 minutes after PG-treatment, long before advanced cyclic IUP evolved. This finding substantiates the conclusion (1–3), based on experiments in animal “models”, that decrease in utero-placental blood flow is an early step in the mechanism of PG action.     

The mechanism of prostaglandin action on the early pregnant human uterus

To extend observations in 11 weeks pregnant patients⁽¹⁾ the mechanism of prostaglandin (PG) action has been examined in 6 weeks pregnant women (LMP). In 10 gravidas menstrual induction was attempted with a single slow release vaginal suppository containing 3000 g (15S)-methyl PGF2α methyl ester (U-36,384). In 10 additional gravidas menstruation was provoked by the intramuscular injection of 500 g 16-phenoxy-ω-tetranor PGE2 methyl sulfonylamide (Sulproston) at 4 hour intervals, totalling 1250 ± 154 g.The PGF2α and PGE₂-analogues provoked similar changes in hormone levels and uterine function, sequentially measured by radioimmunoassays and the recording of intrauterine pressure. However, the effects of the intramuscular regimen developed earlier. Both treatments successfully terminated early pregnancy with clinical symptoms of menstruation if they irreversibly compromised the conceptus within 12 hours. However, while both formulations represent advances in postconceptional therapy, only further modifications may closely approximate the “ideal” method of non-surgical menstrual induction.     

On the mechanism of midtrimester abortions induced by the prostaglandin “impact”

Using Csapo's technique a single dose of 24.3±1.1mg PG F_2α had been delivered intraamniotically to 20 sedated 15.9±0.6 weeks pregnant patients, to provoke a “PG Impact” (PGI), a consequent progesterone (P) withdrawal and a conversion of the pharmacologically refractory normal pregnant uterus into a reactive organ. The side effects were occasional and acceptable and no further PG F_2α treatment was needed except in 4 cases (5–10mg). Only after the Oxytocin Test showed that the uterus is becoming reactive was 50mU/min oxytocin infused i.v., to facilitate the evolution of IUP to 93±3mm Hg and thus promote clinical progress. All the 20 patients aborted both the fetus and the placenta in 16.5±2.1 hours, but 8 women retained small placental residues to be removed by curettage. The Csapo Score was high, 92±2.As early as 3 hours after PGI, the plasma P levels already decreased significantly. They continued to decline throughout the IAT and reach a 72% withdrawal when the fetus was aborted. Fifteen patients, whose P-withdrawal was rapid aborted before the mean IAT, while those 5 women whose P-withdrawal was slow aborted after this time. Thus, the rate of P-withdrawal was directly, while parity and gestational age indirectly related to the IAT. Studies are in progress to elucidate further the abortifacient action of PG F_2α and through this knowledge promote predictable therapy.     

Clonal selection by fluorescence redistribution after photobleaching (FRAP)—A “fast” lateral mobility fibroblast mutant (E7G1)

Fluorescence redistribution after photobleaching (FRAP) was utilized to select a “fast” lateral mobility clone from Kirsten murine sarcoma virus-transformed 3T3 (KMSV-3T3) fibroblasts. The clone, E7G1, demonstrated a lateral mobility for membrane wheat germ agglutinin (WGA) and succinylated concanavalin A (sCon A) receptors of (2.1 ± 1.6) × 10⁻⁹ cm²/s and (2.7 ± 2.3) × 10⁻⁹ cm²/s, respectively. These mobilities were approximately equivalent to phospholipid mobility (2.8 ± 1.9 × 10⁻⁹ cm²/s). The fast mobility phenotype is observed when the cells are unattached and spherical. Upon attachment, the mobility decreases to (0.19 ± 0.19) × 10⁻¹⁰ cm²/s. In addition, the ability of Con A to initiate global modulation was completely lost in spread as well as spherical cells in the E7G1 fast mobility clone. A comparison of F-actin patterns between untransformed Balb/c fibroblasts and the E7G1-transformed line suggests a correlation between well-developed stress fiber assemblies and the ability to induce global modulation. The fast mobility clone was stable for at least 23 passages.     

The efficacy and acceptability of the ″prostaglandin impact″ in inducing complete abortion during the second week after the missed menstrual period

Twenty-two pregnant patients were exposed, 12±1 days after their missed menstrual period, to a single intrauterine dose of 5mg PG F2_α, to provoke a PG ″Impact″ (PGI) and through it legal abortion. The PGI, delivered through the cervix during 10 minutes, induced 83±9mm Hg contracture in 20±3 minutes. Cyclic IUP reached 102±10mm Hg only in 116±14 minutes, it was then sustained for about 2 hours and subsequently declined.During the evolution of IUP uterine bleeding appeared, progesterone (P) and estradiol 17_β (E₂) started to decrease and continued decreasing. At 24 hours after PGI, P-withdrawal was 44% (P<0.05), bleeding continued and cervical dilatation approximated 1cm. Subsequently uterine bleeding (containing tissue fragments) continued and out of 22 women 20 aborted completely. After 3–5 days bleeding declined, the pregnancy tests became negative and normal menstrual periods one month after PGI provided the desired end points of the study. Complete abortions, simulating the symptoms of delayed menstrual periods, had a high Abortion Score of 95 and in the sedated patients the side effects were infrequent, mild and acceptable. This clinical outcome encourages extensive field trials.None of the patients aborted during the short lived period of exogenous PG stimulation. However, the continued steroid withdrawals indicated that PGI damaged the endocrine function of the ovum and the luteotrophic support of the corpus luteum. Therefore, if it was PG which completed abortion eventually, it had to be the endogenous compound, having become effective in physiological concentrations, due to the threshold-lowering action of P-withdrawal.     

Acid dissociation constants and pH values for standard “bes” and “tricine” buffer solutions in 30, 40, and 50 mass% dimethyl sulfoxide/water between 25 and −25 °C

Information is given concerning two standard buffer solutions suitable as pH references in 30, 40, and 50 mass% dimethyl sulfoxide (DMSO)/H₂O mixed solvents at subzero temperatures from −20 to 0 °C, with the intention of establishing a pH (designated pH^*) scale. The two buffers selected were the ampholytes N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid (“bes”) and N-tris(hydroxymethyl)methylglycine (“tricine”), and the reference standard consisted of equal molal quantities of the buffer and its respective sodium salt. The assignment of pH^* values was based on measurements of the emf of cells without liquid junction of the type: Pt;H₂(g,1 atm) ¦Bes, Na Besate, NaCl ¦ AgCl;Ag and Pt;H₂(g,1 atm) ¦Tricine, Na Tricinate, NaCl ¦AgCl;Ag and the pH^* was derived from a determination of K₂, the equilibrium constant for the dissociation process (Buffer)^±/ai (Buffer)⁻ + H⁺.     

“Menstrual induction” with sulproston

The PGE₂-analogue Sulproton (16-phenoxy·ω-17,18,19,20-tetranor-PGE₂-mythylsulfonylamide) was administered to 200 medically and gynecologically normal women who were 17±0.4 days beyond their expected menstrual period and who had a positive pregnancy test. The intramuscular impact dose (500 μg repeated after 4 hours) caused an immediate tonic uterine contraction which compromised the estradiol 17β, progesterone and chorionic gonadotropin production within the fetoplacental unit, and thereby allowed the evolution of cyclic uterine activity, cervical dilatation and tissue expulsion.Pregnancy termination was complete in 92% of women, 5.5% required surgical curettage and 2.5% were given a second Sulproston treatment 2–3 weeks after the first to remove retained tissue from the uterus. The medical induction of menstruation was preferred by 83% of the women who had previously experienced surgical termination of pregnancy. Normal menstruation resumed in all women after 36±0.9 days. The majority of 42 women questioned found Sulproston a satisfactory, safe, simple and effective drug regimen for “menstrual induction”.     

Inhibition of ovulation in the gonadotropin-primed immature rat by exogenous prostaglandin E2

In the past two decades there have been innumerable reports that prostaglandins (PGs) are essential for mammalian ovulation. However, we have recently found that a relatively low dose of 0.03 mg indomethacin (INDO) sc to PMSG/hCG-primed immature Wistar rats can significantly reduce ovarian PG levels without inhibiting the control ovulation rate of 60+ ova/rat (1–3). In view of this information, the present study was an effort to duplicate the earlier reports that PGs can reverse the “inhibitory” effect of INDO on ovulation. In control animals, which received PMSG and hCG only, the ovulation rate was 63.8 ± 4.5 ova/rat. This rate was reduced to 4.1 ± 1.1 ova/rat when the animals were injected with 1.0 mg INDO at 3 h after hCG. In no instance was this inhibition reversed when the animals were treated with 1.0 mg of PGE₂ or PGF_2α, or a combination of both prostanoids in either a single dose at 3 h after hCG, or in 4× doses at 2-h intervals beginning at 3 h after hCG. Furthermore, in animals that did not receive INDO, the ovulation rate in PGE₂-treated animals was reduced to 20.0 ± 6.7 ova/rat, and in animals treated with PGE₂ and PGF_2α (combined) it was reduced to 19.4 ± 6.5 ova/rat. In summary, not only did the PGs fail to reverse the anti-ovulatory effect of INDO, PGE₂ actually suppressed the ovulation rate.     

Menstrual induction with PGF2 alpha and PGE2.

The "prostaglandin impact" (PGI), a massive intrauterine dose of PG, converts the refractory pregnant uterus into a reactive organ by provoking a regulatory imbalance. This regulatory conversion releases the endogenous mechanism of menstruation or abortion. During initial studies, PGI successfully provoked menstrual induction (MI) in 22 and subsequently in 65 volunteers. These results were confirmed and complemented by 2 independent trials in 14 and 36 gravidas respectively. The best clinical outcome was obtained in 20 volunteers, when a "PG-Pellet" (a mini-suppositorium) was inserted in utero, containing only 2.5 mg PGF2alpha. These 157 trials in sedated volunteers had the common features of over 90% efficiency, transient and medically acceptable side effects and infrequent complications. The present study of 542 volunteers focused upon the collection of clinical data regarding efficacy, side effects and complications of MI. All patients had committee approval for legal abortion, during the 2nd week of their missed menstrual period. They volunteered to participate because of their preference for pharmacological rather than surgical pregnancy termination. The clinical outcome of the 542 MI with 5 mg PGF2alpha (428 cases) and 1.5 mg PGE2 (114 cases) was identical. On the average, 95% of the gravidas had complete evacuation of the uterus with the clinical symptoms of delayed menstruation rather than abortion; they experienced spontaneous menstruation in 34 days after having received a single dose of PG.     

Antagonistic effect of enterocin CCM 4231 from Enterococcus faecium on “bryndza”, a traditional Slovak dairy product from sheep milk

“Bryndza” is a traditional Slovak dairy product (type of soft cheese) made from sheep cheese which was ripened for 14 days. Because its manufacture, transporting and/or storing represent conditions which facilitate contamination, the effect of enterocin CCM4231 in “bryndza” was investigated with the aim to reduce the contaminant agents. “Bryndza” was divided into equal portions (50 g). The experimental sample (ES) as well as the control sample one (C1) were inoculated with Listeria innocua Li1 strain. The other control samples C2 and C3 were without Li1 strain. C3 control was selected as a reference control. ES and C2 portions were treated with purified enterocin CCM4231 in a concentration of 6400 AU/ml. Before the experimental inoculation, “bryndza” was checked for the presence of contaminant agents. The experiment lasted 1 week and the samples were stored in the refrigerator at 4 °C. Sampling was performed on day 1, on day 4 and on day 7. The control samples C2 and C3 were checked only on day 1 and then after 1 week. The following contaminant agents were detected in “bryndza” before its experimental inoculation with L. innocua Li1 strain: Escherichia coli in the amount 10³ cfu/ml/g, Staphylococcus aureus (10² cfu/ml/g) and enterococci (10⁴ cfu/ml/g). In the control sample C2, the number of E. coli was reduced to 10² cfu/ml/g. Enterococci and staphylococci were totally eliminated there. Concerning C3 control, natural decrease of bacteria was found and/or their unchanged counts. The value of pH (5) was stable during the whole experiment. In the experimental sample inoculated with Li1 strain, its counts were decreased immediately after enterocin CCM4231 addition approximately by one order of magnitude. This inhibitory effect was also detectable on day 4 by the difference of one order of magnitude between ES and C1. On day 7, 10³ cfu/ml/g of Li1 strain were detected in both samples (ES, C1). The difference by one order of magnitude indicated, an inhibitory effect of enterocin CCM4231 in “bryndza”. However, bacteriocin activity was not determined by laboratory analyses.     

Hydrology of winter–spring “red tides” in Bahía de Mazatlán, Sinaloa, México

“Red tide” events are frequent and periodical in Bahía de Mazatlán, Sinaloa, México. Yet, the ones observed from 4 February to 4 June 2000, showed some distinctive features: First, the dinoflagellates Prorocentrum balticum (85%), P. mexicanum (5%), and Ceratium furca (5%), dominated the composition of the blooms; Second, the average cell abundance by date was 1.3×10⁶ cells l⁻¹, with a range of 3.5×10³ to 24,500 × 10³ cells l⁻¹, well above previous records; Third, the temperature registered at 10–20 m deep was unusually cold (19 °C), below the normal average of 21.5 °C observed over the last 10 years. Salinity was high (35.9 psu) and showed very little influence on the water density gradient. A mean thermal stratification index (TSI), of 3.4, with a maximum of 7 °C, was observed throughout the period, in spite of a weak upwelling activity and intermittent strong NW winds which were unable to break up water column stratification. Temperature fluctuations at the surface and at the bottom layers showed a 30-day periodicity, suggesting some association with the lunar cycle. To explain the characteristics of the “red tides” registered in Bahía de Mazatlán during the winter–spring period of year 2000, it is proposed that the temperature and density stratification, stabilized further by internal waves that compensated for the weak upwelling activity and provided the necessary nutrients to the surface layer, favored the persistence and intensity of the harmful algal bloom events then observed.     

Effect of ibuprofen on menstrual blood prostaglandin levels in dysmenorrheic women

In a randomized crossover study 15 dysmenorrheic women were treated during two consecutive menstrual periods, once with the potent prostaglandin-synthesis inhibitor: ibuprofen and once with an identical looking placebo. Each patient was medicated for 12 hours during the first day of her menstrual flow and was subsequently fitted with a cervical cup for the collection of menstrual blood during three hours. In these samples the concentrations of prostaglandin (PG)F and PGE were measured by radioimmunoassay.The patients receiving placebo had high PGF levels 135 ± 27 ng/ml (Mean ± S.E.) which were significantly reduced by Ibuprofen to 24 ± 5 ng/ml (P<0.001). The PGE concentrations decreased from 5 ± 1 ng/ml to 2 ± 1 ng/ml (P<0.05). Ibuprofen also reduced the menstrual pain significantly (P<0.001). These results substantiate the earlier conclusion that a causal relationship exists between effective treatment with PG-synthesis inhibitors and decrease in menstrual blood PG levels, intrauterine pressure and dysmenorrheic pain.     

Species dependent relaxation of intrapulmonary arteries (IPA) of rabbits, dogs and humans by prostacyclin

Helically cut strips of successive IPA segments of rabbits, dogs and human patients were set up for isometric recording . High tone was produced by norepinephrine (NE, 3 μM). This tone was markedly reduced by prostacyclin (PGI2) in the secondary, tertiary and quaternary branches of human and canine pulmonary trunk. The IC50 values for PGI2 ranged from 22 to 503 nM, the human vessels being more sensitive to prostacyclin than canine IPA. Under these conditions, the primary and secondary branches of the rabbit pulmonary trunk were not relaxed by PGI2. The contractile potency of NE was determined in each pulmonary vessel studied. The secondary segments of rabbit IPA were about ten times as sensitive to NE (EC50 for NE: 38±7 nM) as compared to the secondary IPA from dogs and humans (EC50 values: 370±84 and 440±50, respectively). When high tone was induced by equieffective contractile concentrations of NE (3 μM for canine and human IPA and 0.3 μM for rabbit vessels), PGI2 was still less effective (P<0.01) in relaxing secondary IPA of rabbits (IC25: 220±55) than the corresponding segments of dogs and humans (IC25: 51±12 and 17±4, respectively). The difference between canine and human vessels was also significant (P<0.02). These results indicate that there is an interspecies difference in the sensitivity of IPA to NE and PGI2.     

The effects of progesterone, prostaglandin F2α and oxytocin on the calcium-activation of the uterus

The relationship between “activator-calcium” (A-Ca), progesterone (P), prostaglandin F2α (PGF2α) and oxytocin (Oxy) has been examined in 100 uterine strips of 34 pregnant and 100 strips of 34 post partum rabbits. At the 25th day of gestation, uterine P was 13.9±1.3 ng/g, while within 3–12 hours post partum 3.3±0.3 ng/g tissue (P<0.001). Uterine strips, mounted isometrically in Krebs' solution, sustained maximum excitability in a steady state when exposed every 30 seconds for 4 seconds to an electric field of 12 V/5 cm (a.c.). The maximally contracting muscles were then rinsed at intervals of 6 minutes with Ca-free Krebs.In Ca-free Krebs, the post partum uterus lost 31% of its Ca and 96% of its excitability in a short 25 minutes, while the pregnant uterus lost 30% of its Ca and 93% of its excitability in 50 minutes (P<0.001). Since the extracellular space is 30% in the uterus, this 30% Ca, lost by both muscles, most probably was extracellular Ca and the small A-Ca fraction which is presumably “bound” more strongly at the membrane systems of the P-dominated pregnant, than the non-dominated post partum uterus. The significantly faster and more complete recovery from Ca-deficiency and inexcitability of the pregnant than the post partum uterus (P<0.001), at different levels of external Ca, further substantiates this premise. So does the demonstration that exposure to Ca-free Krebs increases ⁴⁵Ca-efflux 400% in the post partum and only 110% in the pregnant uterus (P<0.001). Exposure to 100 ng/ml PGF2α in normal Krebs has a similar effect on the ⁴⁵Ca-efflux of the post partum uterus, while the response of the pregnant uterus is indistinct (P<0.001).These highly significant differences between the post partum and the pregnant uteri in their Ca-efflux explain the higher threshold (P<0.001) and lower “sensitivity” to PGF2α and Oxy (P<0.001) of the pregnant than the post partum uterus. The already very highly significant differences between the two muscles, in threshold and sensitivity to these two most potent oxytocics, were increased still further by rendering the uterine strips Ca-deficient. All together, these findings substantiate the early contention (1–7,18,19) that uterine function at the cellular level is regulated by opposing actions of the suppressor P and the intrinsic stimulant PG or other oxytocic agents on threshold, excitability and the Ca-activation of the contractile process.     

Cardiovascular responses to an isosterically modified prostaglandin analog in conscious dogs

The cardiovascular effects of oral and intravenous administration of 0.05 and 0.1 mg/kg of the isosterically modified prostaglandin (PG) analog, (+)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-thiazolidinyl]propy} benzoic acid were ascertained in conscious mongrels. After 0.05 mg/kg p.o., mean arterial pressure (MAP), obtained from indwelling catheters, fell from 105 ± 1 to 100 ± 4 mm Hg and total peripheral resistance (TPR) decreased from 0.062 ± 0.006 to 0.039 ± 0.002 mm Hg/ml/min. Cardiac output (CO), measured via electromagnetic flow probes, rose from 1.8 ± 0.2 to 2.6 ± 0.1 l/ml and heart rate from 109 ± 13 to 128 ± 8 beats/min. The 0.1 mg/kg p.o. dose produced similar results. Intravenous injection of 0.1 mg/kg immediately dropped MAP from 103 ± 6 to 58 ± 3 mm Hg and TRP from 0.049 ± .006 to .014 ± .002 mm Hg/ml/min. CO climbed from 2.3 ± 0.2 to 0.2 to 5.3 ± 0.5 l/ml and HR increased from 126 ± 9 to 254 ± 14 beats/min. Stroke volume was not affected by either oral or intravenous administration of the PG analog. Pretreatment with 100 μg/kg timolol blunted the CO and HR responses to 0.1 mg/kg iv of the PG analog without affecting the depressor response. Metaramidol infused during injection of 0.1 mg/kg iv of the PG analog diminished all responses. When compared to the cardiovascular effects of hydralazine and nitroprusside, the profile of the PG analog activity closely resembled that produced by the arterial vasodilator, hydralazine; in contrast, nitroprusside (which also dilates veins) reduced stroke volume, but did not significantly affect HR. In conclusion, dilation of the resistance vessels by the PG analog decreased MAP and TPR and reflexly elevated CO and HR in conscious dogs.     

Age-, cycle- and topographic dependency of human myometrial prostaglandin (6-keto-PGF1a, PGF2a)-synthesis in vitro

Specimens of human myometrium (isthmus and fundus) freshly obtained at hysterectomy were immediately transferred in ice cold Tyrode solution and placed in superfusion chambers. Spontaneous contractions were recorded, the effluent of the myometrium was analyzed for PGF2a and 6-keto-PGF1a by use of specific radioimmunoassay systems. Dating of the menstrual cycle was achieved by histological evaluation of the endometrium.The PG release rates expressed as ng/min/g wet weight were correlated to the patients age and to the phase of the menstrual cycle. The production rates of 6-keto-PGF1a were negatively correlated to the age of the patients and declined in fundus specimens from 2.89 ± 0.35 ng/min/g wet weight in 39–42 years old patients to 0.52 ± 0.17 ng/min/g wet weight in 48–52 years old women during the secretory phase (p< 0.001). Similar significant correlations were found in specimens obtained from the isthmus uteri.During the proliferative phase fundus specimes produced on average 1.61 ± 0.67 ng/min/g wet weight in 39–42 years old patients and0.49 ± 0.12 n/min/g weight 6-keto-PGF1a in 48–52 years old women respectively (p < 0.001).The PGF2a synthesis in myometrial specimens of fundus or isthmus origin was significantly lower than 6-keto-PGF1a and did not correlate to the age of the patients during the proliferative phase. However, PGF2a release rates during the secretory phase were significantly (p < 0.001) higher in younger women.These results suggest an age-, cycle- and topographic dependency of PGI2 synthesis in human myometrial tissue.