Determination of selected coagulation parameters in induced abortion by means of 15-methyl-PGF2 alpha]

There were accomplished investigations about changes of bleeding and recalcification time, platelet count, levels of heat-fibrin, prothrombin, partial thromboplastin time, platelet adhesiveness and heparinocytes at 10 women during induction of therapeutic abortion by use of intramuscular injections of 15-methyl-PGF2 alpha in the first and second trimester of pregnancy. The studies were performed before treatment, 30 minutes, 4 and 8 hours after beginning 15-methyl-PGF2 alpha-administration, 2 hours after expulsion of product of conception and 24 hours after first injection. The following investigations showed statistical significant changes: Prothrombin decreased during treatment with 15-methyl-PGF2 alpha and did not obtain the starting value 24 hours after first injection. Platelet count showed an equal attitude. The heparinocytes showed a continuous falling off up to 2 hours after termination the pregnancy. A significant ascent was noticed 24 hours after first investigation. The results of studies did not indicate a strong injury of coagulation system. They support the positive estimate for induction of therapeutic abortion with 15-methyl-PGF2 alpha in the first and second trimester of pregnancy.     

Intra-amniotic prostaglandin F2α and urea for abortion

Prostaglandin F_2α (PGF_2α) 20 mg combined with urea 80 g was injected intra-amniotically in 20 patients to induce mid-trimester abortion. Abortion resulted in all subjects within 24 hours in a mean time of 12 hours 38 minutes (range 5 hours 50 minutes to 20 hours 45 minutes).Plasma sex steroids were evaluated before and hourly for 5 hours after the injection. A progressive decline in levels occurred with time. Decreases in plasma progesterone, estrone, estradiol and estriol were significant as soon as one hour after injection.Gastrointestinal side effects occurred with a greater frequency than when a comparable dose of PGF_2α is given alone and 2 patients had small cervical lacerations requiring suture. Further studies are indicated to establish whether a lower dose of PGF_2α will be associated with fewer side effects and be as effective.     

Prostaglandin-induced pregnancy termination: Further studies using gemeprost (16, 16 dimethyl-trans-Δ-PGE1 methyl ester vaginal pessaries in the early second trimester

The use of gemeprost (16, 16 dimethyl-trans-Δ²-PGE₁ methyl ester) vaginal pessaries for the termination of pregnancy in the early second trimester has been further investigated. Of 113 women between 12 and 16 weeks gestation, 93 (82%) aborted within 24 hours of the administration of 4.4 ± 0.1 1mg gemeprost pessaries. The mean induction — abortion interval was 881 ± 31 minutes. Successful abortion was achieved in 16 of the remaining 20 women after a second course of gemeprost pessaries without the need for oxytocin supplementation. There were no serious complications. Crampy abdominal pain and vaginal bleeding started after 275 and 756 minutes respectively. Twenty-two (19%) patients did not require pain relief during treatment, but 90 (80%) required parenteral opiates. Vomiting and diarrhoea occured in 16 (14%) and 23 (20%) cases respectively. The safe induction of therapeutic abortion in 96% of women using vaginal prostaglandin alone offers an acceptable alternative to surgical evacuation in the early second trimester.     

Changes in prolactin levels caused by luteinizing hormone releasing hormone

The acute effects of luteinizing hormone releasing hormone (LHRH) on the release of prolactin (PRL) were investigated in 12 normal cycling women and 42 women with various menstrual disorders. LHRH (100 micrograms) was bolusly injected intramuscularly and PRL levels were measured immediately before the injection and at 30 minutes and 60 minutes after the injection. LHRH elicited an increase of more than 25% in PRL levels in 15 cases (27.8%) at both 30 minutes and 60 minutes after the injection, whereas PRL levels were decreased by more than 25% in 7 cases (13.0%). The PRL response to LHRH seemed to be related to basal PRL levels. Especially when the PRL concentration was 20 ng/ml or more, LHRH decreased PRL levels in 7 cases out of 16. On the other hand, LHRH increased PRL levels in the majority of cases with a PRL concentration less than 20 ng/ml. In conclusion, the LHRH injection occasionally alters PRL levels in either a positive or negative manner, depending upon the basal PRL levels.     

Prostaglandin-induced pregnancy termination: further studies using gemeprost (16,16 dimethyl-trans-delta 2-PGE1 methyl ester) vaginal pessaries in the early second trimester

The use of gemeprost (16,16 dimethyl-trans-delta 2-PGE1 methyl ester) vaginal pessaries for the termination of pregnancy in the early second trimester has been further investigated. Of 113 women between 12 and 16 weeks gestation, 93 (82%) aborted within 24 hours of the administration of 4.4 +/- 0.1 1 mg gemeprost pessaries. The mean induction-abortion interval was 881 +/- 31 minutes. Successful abortion was achieved in 16 of the remaining 20 women after a second course of gemeprost pessaries without the need for oxytocin supplementation. There were no serious complications. Crampy abdominal pain and vaginal bleeding started after 275 and 756 minutes respectively. Twenty-two (19%) patients did not require pain relief during treatment, but 90 (80%) required parenteral opiates. Vomiting and diarrhoea occurred in 16 (14%) and 23 (20%) cases respectively. The safe induction of therapeutic abortion in 96% of women using vaginal prostaglandin alone offers an acceptable alternative to surgical evacuation in the early second trimester.     

alpha-melanocyte-stimulating hormone and habituation of prey-catching behavior in the Texas toad, Bufo speciosus.

We investigated dose-dependent effects of alpha-melanocyte-stimulating hormone (alpha-MSH) on habituation in the Texas toad, Bufo speciosus. Additionally, we determined changes in plasma and brain levels of alpha-MSH following peripheral administration of the peptide or following exposure to an ether stressor. The ability of alpha-MSH to facilitate acquisition of habituation was dose dependent. Plasma alpha-MSH concentrations were elevated within 5 min of dorsal lymph sac injection and remained elevated up to 600% over controls after 30 min. Administration of 50 microgram alpha-MSH had no effect on plasma corticosterone levels. Radiolabeled alpha-MSH was detected in cerebrospinal fluid microdialysates within minutes of peripheral injection. Concentrations of alpha-MSH in the telencephalon and preoptic area were significantly lowered after ether exposure, whereas levels in the optic tectum, thalamus/hypothalamus, brainstem, and plasma were unchanged. We conclude that alpha-MSH administered peripherally facilitates habituation in a dose-dependent fashion. Our results confirm that the effects of alpha-MSH are independent of corticosterone secretion. The peptide is cleared rapidly into the bloodstream and enters the cerebrospinal fluid after dorsal lymph sac injection. Neuronal alpha-MSH may help toads gather information about their environment when exposed to certain stressors.     

The progesterone derivative dydrogesterone abrogates murine stress-triggered abortion by inducing a Th2 biased local immune response

Stress is known to induce abortions in mice and humans, putatively via increased levels of abortogenic Th1 cytokines and a decrease of progesterone. Adequate levels of progesterone exert an antiabortive response through binding to the progesterone-receptor, which induces the release of progesterone-induced blocking factor (PIBF) from lymphocytes. PIBF is highly pregnancy-protective by induction of a Th2 biased immune activity. The aim of this study was to investigate the effect of the progesterone derivative dydrogesterone (6-dehydro-retroprogesterone) in stress-triggered murine abortion. DBA/2J-mated CBA/J female mice were randomized in different groups: two groups were treated with different dydrogesterone dosages in a single injection before exposure to sound stress on Day 5 of pregnancy, one group was exposed to stress without dydrogesterone treatment, the fourth group received no stress and no dydrogesterone. On gestation Day 13, a highly elevated abortion rate was detected in stressed mice compared to control mice. Stressed animals presented lower levels of progesterone and PIBF in plasma and a reduced staining intensity of progesterone receptor at the feto-maternal interface. Injection of dydrogesterone abrogated the effect of stress on the abortion rate. Further, dydrogesterone increased levels of plasma PIBF in stressed mice, but did not affect progesterone levels. Interestingly, dydrogesterone dramatically increased the percentage of IL-4 positive decidual immune cells in stressed mice. Our data suggest that dydrogesterone abrogates stress-triggered abortion by inducing a Th2 biased local immune response.     

Induction of midtrimester abortion by serial intravaginal administration of 15(S)-15-methyl-prostaglandin F2alpha (THAM) suppositories.

Midtrimester abortion was successfully induced in 13 of 22 patients by serial intravaginal administration of 15(S)-15-methyl-prostaglandin F2alpha (THAM) suppositories. Nine patients, 4 nulliparas and 5 multiparas, failed to abort after 24 hours of prostaglandin administration and a concomitant infusion of oxytocin was initiated. Seven of the nine patients aborted within 7 hours of the combined therapy and one patient on methadone maintainence aborted after 17.5 hours of combined therapy, 41.5 hours after the first dose of prostaglandin. A single patient failed to abort, despite the concomitant prostaglandin-oxytocin administration and underwent surgical evacuation. The mean abortion time for the 21 successful abortions was 22.56 hours. Nulliparous patients aborted somewhat faster, mean 21.79 hours, than multiparous patients, mean 23.80 hours, but this difference was not statistically significant. In this study, one patient aborted in less than 12 hours, and 62% of the successful cases aborted within 24 hours. The plasma levels of 15-ME-PGF2alpha were analyzed by radioimmunoassay in 10 patients. Plasma prostaglandin levels rose significantly 30 minutes after the insertion of the first suppository, but there was a wide variation in levels from patient to patient. It was observed that the 2 patients with the highest levels had the fastest abortion times and episodes of gastro-intestinal side effects appeared related to a rise in prostaglandin levels. Sixty-four percent of the patients in this study had no gastro-intestinal side effect related to prostaglandin administration.     

Plasma Concentrations of Testosterone in the Male Dog and Plasma Testosterone Profile Following Single Intramuscular Injection of HCG

The spontaneous variation in plasma testosterone was studied in 4 dogs in a 24 h period. Blood samples were taken with 1½ h interval. A variation of 26–62 % was found in the plasma testosterone concentration and the values ranged from 2.7–15.6; 0.7–10.4; 4.2–17.3; 8.7–23 nmol/l. No effect of intramuscular injection of 150 i.u. HCG could be seen on the plasma testosterone levels in samples taken 5, 10, 20 or 30 min post injection. Thereafter plasma testosterone levels increased to reach levels equal to peak concentration in the control period 1½ h post injection. The variation in the plasma testosterone concentration 1½, 3 and 4½ h post HCG injection was reduced to 8.95 ± 2.8 % (mean ± s). Plasma testosterone in a sample taken 3 h after HCG injection might thus be indicative of a Leydig cell dysfunction in the dog. An additional increase (P < 0.001) in plasma testosterone levels was observed 21–30 h post injection. Thereafter levels of testosterone fell to pre-stimulation values.     

Time-dependent inhibition of platelet cyclo-oxygenase by indomethacin is slowly reversible

Indomethacin has been charterized as a time-dependent, irreversible inhibitor of cyclo-oxygenase, yet its effects on human platelets have been found to be reversible . To understand this apparent contradiction, we have investigated the kinetics of recovery of platelet thromboxane production after a single dose of indomethacin. The inhibition of platelet thromboxane production was greater than would be expected from the levels of indomethacin found in the plasma suggesting that the time-dependent inhibition occurs . Yet recovery of platelet thromboxane production was faster than expected for the irreversible inhibitor, with 50% of control values being regained within 24 hours after ingestion of the drug. When platelets were isolated and resuspended in homologous drug-free plasma, slow recovery of thromboxane production was seen to occur with 50% of control activity regained in 100 minutes. This recovery was much slower than that seen from a competitive inhibitor of cyclo-oxygenase, ibuprofen. Ibuprofen-treated platelets recovered nearly completely immediately on being resuspended in drug-free plasma. When microsomes were isolated from platelets, then treated with indomethacin, no time-dependent recovery of activity was seen. The recovery of cyclo-oxygenase after indomethacin inhibition appears to be limited to the unperturbed enzyme in this natural milieu.     

The Disappearance Rate in Reindeer of Famphur an Organophosphorus Parasiticide

The present investigations were carried out in order to study the disappearance rate in reindeer of famphur (0,O-dimethyl-O,p-(NtN-di-methylsulphamoyl) phenyl phosphorothioate), a promising systemic parasiticide for the control of reindeer warble and nostril flies. The compound was administered intramuscularly to reindeer as a single dose (in the form of the preparation Warbcx). At a dose of 20 mg/kg body weight (2 animals) famphur caused inhibition of plasma and erythrocyte cholinesterase activities by about 50 %. The plasma esterase activity fell off rapidly, within 24 hrs., and returned to normal within 3 weeks, whereas the erythrocyte esterase activity decreased gradually and remained low for at least 4 weeks after dosing. Peak plasma levels of fampliiir, varying between 1 and 16 p.p.m., were attained within 5–33 hrs., after a dose of 30 mg famphur per kg body weight (7 reindeer). The plasma levels declined to below 0.02 p.p.m. in 72–96 hrs. Famoxon, the oxygen analogue of famphur, was observed for 1–2 days in plasma at low levels, amounting to about 10 % of the corresponding famphur levels. In erythrocytes practically no residues were found of either compound. Tissue residue levels were low — except at the injection site. In a series of animals given a dose of 30 mg/kg body weight and killed at varying times after treatment famphur or famoxon were detectable in liver for 4.5 days and in kidney and skeletal muscle remote from the injection site for 12 days. In muscle tissue from the injection site highly variable residue levels were observed, indicating absorption from the intramuscular depot to be erratic. The experimental results suggest that no appreciable consumer hazard would arise from a proposed single-dose intramuscular treatment of reindeer with famphur at a dosage not exceeding 30 mg/kg body weight, provided a minimum interval of 3 weeks is maintained between treatment and slaughter and the muscle tissue around the injection site is discarded.     

Induction of midtrimester abortion by serial intravaginal administration of 15(S)-15-methyl-prostaglandin F2α (THAM) suppositories

Midtrimester abortion was successfully induced in 13 of 22 patients by serial intravaginal administration of 15(S)-15-methyl-prostaglandin F_2α (THAM) suppositories. Nine patients, 4 nulliparas and 5 multiparas, failed to abort after 24 hours of prostaglandin administration and a concomitant infusion of oxytocin was initiated. Seven of the nine patients aborted within 7 hours of the combined therapy and one patient on methadone maintainence aborted after 17.5 hours of combined therapy, 41.5 hours after the first dose of prostaglandin. A single patient failed to abort, despite the concomitant prostaglandin-oxytocin administration and underwent surgical evacuation. The mean abortion time for the 21 successful abortions was 22.56 hours. Nulliparous patients aborted somewhat faster, mean 21.79 hours, than multiparous patients, mean 23.80 hours, but this difference was not statistically significant. In this study, one patient aborted in less than 12 hours, and 62% of the successful cases aborted within 24 hours. The plasma levels of 15-ME-PGF_2α were analyzed by radioimmunoassay in 10 patients. Plasma prostaglandin levels rose significantly 30 minutes after the insertion of the first suppository, but there was a wide variation in levels from patient to patient. It was observed that the 2 patients with the highest levels had the fastest abortion times and episodes of gastro-intestinal side effects appeared related to a rise in prostaglandin levels. Sixty-four percent of the patients in this study had no gastro-intestinal side effect related to prostaglandin administration.     

Incorporation of a circulating protein into alpha granules of megakaryocytes

In order to determine whether or not proteins circulating in plasma can be incorporated into megakaryocytes and platelets, horseradish peroxidase (HRP) was injected intravenously into guinea pigs and these cells were examined for uptake by cytochemistry and electron microscopy. Enriched samples of megakaryocytes enabled ultrastructural analysis of large numbers of these rare bone marrow cells. In megakaryocytes, more than 50% of alpha granules contained HRP between 75 minutes and 7 hours after injection. At 24 hours, 25% of the megakaryocyte granules were peroxidase positive; less were so by 48 hours and none at 4 days. Thus, the findings demonstrate that a circulating protein can be endocytosed by megakaryocytes and rapidly packaged into alpha granules. A precipitous drop in circulating platelet numbers was observed 45 minutes after injection. At this time, circulating platelets showed the tracer only on the platelet plasma membrane, and none in platelet granules. Platelet numbers increased to 35% by 7 hours and only the platelet granules contained HRP. These platelets secreted the HRP stored in granules in response to thrombin. Unfortunately, our present studies do not allow us to distinguish between direct endocytosis by the platelet and/or shedding of new platelets from recently labeled megakaryocytes. Our studies are the first to demonstrate an endocytic pathway by which megakaryocytes can incorporate a circulating protein into alpha granules. An important physiologic implication of this endocytic pathway is the possible origin of certain alpha granule proteins from plasma.     

Time-dependent inhibition of platelet cyclooxygenase by indomethacin is slowly reversible

Indomethacin has been characterized in vitro as a time-dependent, irreversible inhibitor of cyclo-oxygenase, yet its effects on human platelets have been found to be reversible in vivo. To understand this apparent contradiction, we have investigated the kinetics of recovery of platelet thromboxane production after a single dose of indomethacin. The inhibition of platelet thromboxane production was greater than would be expected from the levels of indomethacin found in the plasma suggesting that the time-dependent inhibition occurs in vivo. Yet recovery of platelet thromboxane production was faster than expected for an irreversible inhibitor, with 50% of control values being regained within 24 hours after ingestion of the drug. When platelets were isolated and resuspended in homologous drug-free plasma, slow recovery of thromboxane production was seen to occur with 50% of control activity regained in 100 minutes. This recovery was much slower than that seen from a competitive inhibitor of cyclo-oxygenase, ibuprofen. Ibuprofen-treated platelets recovered nearly completely immediately on being resuspended in drug-free plasma. When microsomes were isolated from platelets, then treated with indomethacin, no time-dependent recovery of activity was seen. The recovery of cyclo-oxygenase after indomethacin inhibition appears to be limited to the unperturbed enzyme in its natural milieu.     

The effect of a 10 cm2, 0.5% 15-ME-PGF2α methyl ester intravaginal silastic device on abortion and plasma prostaglandin concentration

Intravaginal insetion of a 10 cm² silastic device with an 0.5% concentration of 15(S)-15-methyl-prostaglandin F_2α methyl ester alone successfully induced abortion in 27 of 48 patients in the midtrimester and in an additional 11 patients with a concomitant infusion of oxytocin. The mean abortion time for the 38 successful induction was 15.35 hours. In 8 of the 10 patients who failed to abort even with concomitant oxytocin therapy, abortion was induced by serial intramuscular injections of 15-ME-PGF_α; the remaining 2 failures underwent surgical evaccution. The plasma levels of 15-ME-PGF_2α methyl ester in the 11 patients studied varied widely over the first 2 hours after insertion of the device. The maximum mean level was achieved at 2 hours, maintained at 4 hours and then dropped sharply at 8 hours and declined over the abortion period in undelivered patients. Vomiting and diarrhea were the most common side effects and in general well tolerated by the patients. However, there was an adverse reaction in a single patient who experienced almost constant nausea, vomiting and diarrhea. The device was removed 1 hour 50 minutes after insertion and the patient aborted spontaneously 7 hours later. Intravaginal insertion of a silastic device is an effective means of prostaglandin abortion, but their investigation is required to determine the most effective device which would provide a slow, continuous release of the prostaglandin.     

Central cardiovascular effects of mammalian neurohypophyseal peptides in conscious rats

To confirm and extend the results of previous studies which demonstrated central cardiovascular effects of vasopressin in anesthetized rats, we determined blood pressure and heart rate changes for 30 minutes after intracerebroventricular injections of arginine vasopressin, arginine vasotocin and oxytocin in conscious rats. As compared to sham injections, significantly greater increases in either systolic or diastolic blood pressure were noted over the 30 minutes which followed the injection of 0.15, 1.0 or 10.0 nM of either vasopressin or vasotocin. In animals given vasopressin, plasma levels of the peptide were determined. There was a substantial increase in plasma vasopressin only after the highest dose. Overall blood pressure responses to doses of oxytocin as high as 100 nM were not significantly different than sham injections. Heart rate following both vasopressin and vasotocin was increased at 0.15 nM, was initially decreased then increased at 1.0 nM and was substantially decreased after the 10.0 nM dose. There was a significant increase in heart rate at the 10.0 nM and 100 nM doses of oxytocin. Dose response curves for systolic blood pressure and heart rate 20 minutes after injection were similar for vasopressin and vasotocin. We conclude that arginine vasopressin has significant central pressor and tachycardic effects in conscious rats, and it is related, at least in part, to the tail structure of the peptide, which is shared with arginine vasotocin.     

Plasma levels of the methyl ester of 15-methyl PGF2α in connection with intravenous and vaginal administration to the human

After intravenous injection of the methyl ester of 15-methyl-PGF_2α the drug initially disappeared faster than the corresponding free acid, but still after one hour, about 1% of the active drug is circulating in plasma. Vaginal administration of single suppositories containing 1 mg of 15-methyl-PGF_2α methyl ester and determination of plasma levels using gas chromatography - mass spectrometry demonstrated that the highest plasma levels were reached after 1.5 - 3 hours.Vaginal suppositories were administered according to different dose schedules for induction of abortion and plasma levels of 15-methyl-PGF_2α and it's ester were determined. There seemed to be a gross correlation between given doses and obtained plasma level. The data will serve as basis for further development of vaginal delivery devices.     

Blood plasma levels of lipoperoxides,glutathione peroxidase,beta carotene,vitamin A and E in women with habitual abortion

The plasma levels of lipoperoxides, glutathione peroxidase (GSH-Px), reduced glutathione (GSH), beta carotene, vitamin A, E, some plasma biochemical and blood haematological parameters were investigated in 40 women with habitual abortion (HA) and controls. The levels of GSH, vitamin A, E and beta carotene were significantly lower in women with HA than in controls. However, the plasma levels of lipid peroxidation, alkaline phosphatase (ALP), glucose and blood haemoglobin were significantly higher in HA than in controls. In addition, plasma levels of GSH-Px, AST, ALT, total bilirubin, total protein, albumin, sodium, potassium, calcium and number of white blood cells, red blood cells, platelet and values of packet cell volume showed no significant differences between HA and controls. According to the results of this study, we observed that the levels of lipid peroxidation were increased and plasma levels of vitamin A, E and beta carotene were decreased in HA. The decrease of those antioxidants may play a significant role in women with habitual abortion. Copyright © 1998 John Wiley & Sons, Ltd.     

Factors modifying the effect of diazepam on plasma corticosterone levels in rats

We have examined factors that alter the effect of diazepam (DZ) on plasma corticosterone (CS) in rats. DZ had a biphasic effect on plasma CS levels: CS decreased with doses below 5 mg/kg and increased with higher doses. Peak response occurred 90 minutes post injection in both sexes. Plasma DZ levels were significantly higher in females than in males and peak at 10 and 30 minutes post injection in males and females, respectively. There was also a sex difference in the pattern of DZ metabolites. An acute stressor (30 minutes of immobilization) did not affect plasma CS levels in rats injected with a 5 mg/kg dose of DZ. Prenatally stressed animals did not differ in basal CS levels or in their response to 5 mg/kg of DZ compared to prenatally non-stressed animals. These two groups of animals also did not differ in plasma levels of DZ or of its metabolites. By contrast, the 5 mg/kg dose of DZ had no effect on plasma testosterone levels in control animals, but increased it in prenatally stressed animals. Furthermore, compared to non-stressed controls, prenatally stressed animals had lower baseline plasma testosterone levels. These results indicate that the effect of DZ on plasma CS is influenced by endogenous as well as exogenous factors and that these effects vary with the particular biochemical parameter under examination.     

Intraperitoneal injection of zymosan in mice induces pain, inflammation and the synthesis of peptidoleukotrienes and prostaglandin E2

Intraperitoneal injection of zymosan in mice induced rapid extravasation and accumulation of plasma protein in the peritoneal cavity. Neutrophils began to appear in the peritoneal cavity after a lag period of approximately 3 hours. The injected mice exhibited a pain response (writhing) during the first 30 minutes after injection, but writhing ceased before protein or cell accumulation had reached maximum levels. The injection of zymosan induced synthesis of PGE2 (measured by RIA) which reached maximum levels at 30 minutes, then declined slowly. Peptido-leukotriene levels (detected by bioassay, RIA and HPLC) increased rapidly after injection, reached a peak within an hour of injection and declined to undetectable levels within 4 hours. The early peptido-LT was predominantly LTC4, while later, LTE4 was the major component. LTD4 levels remained low throughout and no LTB4 was detected at any time. Indomethacin treatment elevated levels of peptido-LTs, reduced PGE2 levels and inhibited writhing. Phenidone reduced peptido-LT levels. In vitro studies demonstrated that zymosan stimulates LTC4 synthesis by peritoneal cells whereas LTE4, LTD4, LTB4 or monoHETES were not detectable (using HPLC methods). The source of enzymes responsible for the in vivo metabolism of LTC4 to LTD4 and LTE4 could not be identified.