SEARCH · PubMed Health

Results for “Luteolytic Effects”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed1999

Progesterone and estradiol secretion by porcine luteal cells is influenced by individual and combined treatment with prostaglandins E2 and F2alpha throughout the estrus cycle.

The present experiments were conducted to test whether the ratio of PGE2:PGF2alpha affects steroid secretion by porcine luteal cells. We examined the effect of separate and combined treatment with PGE2 and PGF2alpha on progesterone and estradiol secretion. Luteal cells were collected at three different stages of the luteal phase (1-3 days after ovulation; 10-12 days after ovulation and 14-16 days after ovulation). PGE2 alone in a dose dependent manner increased progesterone production by cells collected from mature corpora lutea. On the other hand, PGF2alpha in a dose dependent manner decreased progesterone secretion by cells of the same origin. Progesterone secretion by cells isolated from mature and regressing corpora lutea and treated with both prostaglandins increased in comparison to PGF2alpha-treated cultures. However, in cells collected from regressing corpora lutea PGE2 and PGF2alpha in a ratio of 2:1 and 4:1 increased estradiol production when compared to control and both ratios increased estradiol secretion in comparison to PGF2alpha-treated cells. These data 1) confirm the luteotropic effect of PGE2 and the luteolytic effect of PGF2alpha; 2) demonstrate that when the ratio of PGE2 to PGF2alpha changed from 1:1 to 2:1 or 4:1 cells were protected against the inhibitory effects of PGF2alpha on progesterone secretion by cells collected during the mid- and late luteal phase; and 3) suggest that elevated estradiol production by luteal cells, isolated during late luteal phase, under the influence of increased doses of PGE2 may serve as an additional source of estradiol to blastocysts, during early pregnancy in the pig.

Animals↗

PubMed1992

[Effect of a new prostaglandin aroxaprostol on the contractile activity of the uterus and its abortive action in experimental studies].

Experiments with pregnant and nonpregnant rats have shown that aroxaprostol, a group F2 alpha prostaglandin, injected intravenously and intramuscularly in a dose of 50 micrograms/kg, stimulates the uterine bioelectric activity, increasing both the amplitude and frequency of biopotentials, this evidencing intensification of its contractility. Aroxaprostol has shown an abortive effect, that was related to the luteolytic effect of the drug, manifesting by reduction of progesterone level in the ovaries.

Abortifacient Agents↗

PubMed1985

Effects of progesterone, oestradiol benzoate and cloprostenol on luteal function in the heifer.

The effects of treatment with intravaginal progesterone (PRID) oestradiol benzoate and cloprostenol at various stages of the oestrous cycle were examined in 2 experiments. In Exp. 1, PRIDs were inserted for 14 days commencing on Day 3, 10 or 17 of the oestrous cycle and half the animals in each group received 5 mg oestradiol benzoate at PRID insertion. Plasma samples were collected daily from the time of PRID insertion for 16 days, then every 4 days for a further 24 days. Samples were analysed for plasma progesterone concentration. In Exp. 2, heifers were treated on Day 10 as in Exp. 1, but half of each treatment group received 750 micrograms cloprostenol at PRID insertion. In Exp. 1, treatment with PRID alone appeared to inhibit endogenous progesterone production when treatment began on Day 3, but not when treatment began on Days 10 or 17. Treatment with oestradiol benzoate at the time of PRID insertion depressed progesterone levels, from about 2-5 days after injection. When treatment began on Day 10, the fall in progesterone levels after oestradiol benzoate was preceded by a marked rise in levels. In Exp. 2, treatment with cloprostenol markedly reduced peripheral concentrations of progesterone and also removed the effect of oestradiol. We suggest that oestradiol benzoate had a luteolytic effect, depressing luteal progesterone production when given on Days 3, 10 or 17 and that when given on Day 10 there was a transitory luteotrophic effect which preceded its luteolytic action.

Animals↗

PubMed1982

Failure to induce early abortion by huge doses of a superactive LRH agonist in women.

The possible abortifacient effect of the potent stimulatory luteinizing hormone-releasing hormone analogue D-Ser(TBU)6-EA10-LRH was studied in five women in early pregnancy. Four of them were treated by intravenous injections of the superactive LRH agonist in a dose of 50-125 micrograms t.i.d. for four days (total dose 600-1500 micrograms). The fifth woman discontinued treatment after the first 50 micrograms dose. The treatment was instituted on gestational day 37, 38, 40, 42 and 46. Clinical examinations and frequently taken peripheral venous blood samples for analyses of human chorionic gonadotropin and ovarian steroids were used for monitoring the treatment. No abortifacient effects of these large doses of the superactive LRH agonist were observed and the pregnancies had to be terminated by suction curettage after 10-13 days. Thus, previously described luteolytic effects by superactive LRH agonist are overcome probably by endogenous chorionic gonadotropin in early human pregnancy.

Abortion, Induced↗

PubMed1990

Effects of endotoxin infusion on circulating levels of eicosanoids, progesterone, cortisol, glucose and lactic acid, and abortion in pregnant cows.

The effects of Escherichia coli endotoxin infusions (1.0 or 2.5 micrograms kg-1 over 6 h) on pregnancy were investigated in cows in the first, second and third trimester of gestation. Endotoxin increased the plasma levels of prostaglandins (PGs), thromboxane B2 and cortisol, and decreased progesterone. The severity of the clinical signs and the magnitude of the increases in plasma PGs, thromboxane B2 and cortisol tended to depend on the dose of endotoxin, but were independent of the gestation period. There was hyperglycemia followed by hypoglycemia and lactic acidemia. Hyperglycemia and lactic acidemia were significant only at the high dose of endotoxin. Endotoxin infusion at both doses caused a preferential mobilization of oleic acid from adipose tissue, and also had some effects on the mobilization of palmitic and stearic acids during the post-infusion period. The cows in the first trimester of gestation were more sensitive to the abortifacient effect of endotoxin than cows in the second and third trimester of gestation. The results of this study indicate that the mechanism of endotoxin-induced abortion in cows initially involves a prolonged release of PGF2 alpha and its subsequent stimulant effect on uterine smooth muscle contraction and luteolytic effect leading to a gradual decline in the plasma levels of progesterone. It was concluded that pregnancy terminates in the absence of an adequate level of progesterone, especially during the first trimester of gestation, when progesterone of extraluteal origin is not yet available, coupled with the PGF2 alpha-induced propulsive contraction of the uterus. In addition, the metabolic and circulatory failures in severe cases of endotoxemia, especially at the high dose of endotoxin, resulting either directly or indirectly via the release of various autacoids, catecholamines and cortisol, may also contribute to the termination of pregnancy at any stage of gestation.

Abortion, Veterinary↗

PubMed1995

Prevention of human recombinant interleukin-1 beta (rhIL-1 beta) embryolethality with progesterone or indomethacin.

PROBLEM: Bropirimine and tilorone were found in earlier studies to be embryolethal when administered to Crl:TUC(SD)spf (TUC) rats on gestation day 10. Progesterone or indomethacin could, at least partially, prevent this effect. The immunomodulators appeared to mimic the luteolytic effects of PGF2 alpha, resulting in a shutdown in progesterone release by the corpora lutea, followed by a disruption in maternal support to the pregnant uterus and embryolethality. Since bropirimine has been shown to induce interleukin-1, and since this cytokine has been found to increase PGF2 alpha levels in human decidual cells, the decision was made to investigate whether human interleukin-1 beta might act in an analogous manner to bropirimine and tilorone. METHOD: Bropirimine (400 mg/kg, p.o.) or rhIL-1 beta (20, 30, or 40 micrograms/kg, s.c.) was administered on gestation day 10 to Crl:CD[BR] (CD) or TUC rats, alone and in combination with progesterone (2 mg/kg/day, s.c.) or indomethacin (0.6 mg/day, s.c., days 9-11). On gestation day 14 the dams were killed and their uterine contents examined. RESULTS: rhIL-1 beta (30-40 micrograms/kg) was embryolethal when administered to CD or TUC rats on gestation day 10. Progesterone or indomethacin coadministration prevented, at least partially, the embryolethality seen when rhIL-1 beta was administered (30 micrograms/kg) to TUC rats. CONCLUSION: Evidence was obtained in support of the hypothesis that interleukin-1 is involved in the embryolethal actions of the immunomodulators bropirimine and tilorone.

Adjuvants, Immunologic↗

PubMed1982

[Effects of 16,16-dimethyl-trans-delta 2-PGE1 methyl ester (ONO-802) on reproductive function (author's transl)].

Effects of ONO-802 on maintenance of pregnancy, luteal function and ovulation were investigated. In pregnant rats, ONO-802 given i.p. showed antinidatory, abortifacient and strong labor-inducing effects with treatment on day 2, after day 17 and on day 21 of gestation, respectively. The abortifacient effect was not apparent when treatment was given from day 4-15. PGE1 had an antinidatory effect, PGF2 alpha had an abortifacient and labor-inducing effects after implantation, and PGE2 had both these effects. PGF2 alpha and PGE2 showed a luteolytic effect in rats, while ONO-802, similarly to the findings with PGE1, had no such effect. In pregnant rabbits, intraperitoneal ONO-802, exhibited antinidatory and abortifacient effects after implantation. Abortifacient effects were more potent with the progression of pregnancy of pregnancy though relatively large doses of ONO-802 were required. A significant decrease in peripheral blood progesterone level was observed in the group on high doses but the abortifacient effect of ONO-802 did not always depend on the decreases in the levels of progesterone. In cycling, spontaneously ovulating rats, the high doses of ONO-802 suppressed spontaneous ovulation when these doses were given two at 14:30 and 15:30 on the day of proestrus. ONO-802 did not inhibit the HCG-induced ovulation and the ovulation suppressed by ONO-802 was recovered by PGE2 or HCG.

Abortifacient Agents↗

PubMed1981

[Effects of 16,16-Dimethyl-trans-delta 2-PGE1 methyl ester (ONO-802) on uterine, placental and ovarian circulation (author's transl)].

Doses of the drugs which produce uterine contraction were given intravenously to various species of animals. Placental and ovarian circulations were measured by the thermocouple method and/or microangiography. Uterine arterial blood flow (UABF) was measured by the electromagnetic flowmeter. Both placental blood flow (PBF) and UABF decreased with the administration of ONO-802, PGE1 or PGF2 alpha to to rabbits and dogs. Oxytocin and noradrenaline also decreased PBF in rabbits. ONO-802 or PGE1 lowered arterial blood pressure (BP) in rats, rabbits and dogs. PGE2 alpha elevated BP in rats and dogs and lowered it in rabbits. Oxytocin produced no changes in PB while noradrenaline elevated BP in rabbits. Ovarian blood flow in pregnant rabbits was reduced by ONO-802, PGE1 or PGF2 alpha. Little influence was seen with oxytocin. Regarding the luteal microvasculature in pregnant rats, ONO-802, PGF2 alpha and noradrenaline exhibited vasoconstricting effects. PGF2 alpha induced abortion and decreased plasma progesterone levels. These results suggest that the inhibitory effects of ONO-802 on the uterine and placental circulation are strongly influenced by the uterine contractile effect and that the inhibitory effect on the ovarian circulation in rats is one of pharmacological effects not concerned with the abortifacient or luteolytic effect.

Alprostadil↗

PubMed1980

Luteolysis induced by a luteinizing hormone-releasing hormone agonist is prevented by human chorionic gonadotropin.

The superactive stimulatory luteinizing hormone-releasing hormone (LRH) analogue D-Ser(TBU)6-EA10-LRh was administered intranasally to five healthy women in a daily dose of 600 microgram during two successive days of the mid-luteal phase. Both the basal serum progesterone levels and the length of the luteal phase were reduced, i.e. luteolysis occurred. Three women who were given additional treatment with human chorionic gonadotropin (HCG) in a daily intramuscular dose of 1500 IU for 10 days, had increased basal progesterone levels and a prolongation of the luteal phase. Thus, HCG prevented the luteolytic effect caused by the LRH agonist.

Adult↗

PubMed1977

The effect of prostaglandin f2alpha on endocrine parameters in early pregnancy.

The luteolytic effect of prostaglandin f2alpha (PGF2alpha) has been well documented in a variety of primates. This property has not been proven in early human pregnancy. A study of the luteolytic activity of extraamnial administration of 5 mg PGF2alpha was carried out on 7 healthy women who were less than 6 weeks pregnant and on 4 women who were more than 9 weeks pregnant. Serum levels of 17beta-estradiol, 17-hydroxyprogesterone, progesterone and human chorionic gonadotropin (HCG) were measured by radioimmunoassay before, during and after the administration of PGF2alpha. Abortion was successfully induced in all the patients with early pregnancies, but in the control group of more mature pregnancies only one of the four women aborted. In the older pregnancies, the administration of 5 mg PGF2alpha caused no significant alteration in the serum levels of the measured hormones. In the younger pregnancies the serum concentration of 17beta-estradiol and progesterone decreased within hours after PGF2alpha administration. Serum 17-hydroxyprogesterone concentrations remained unchanged at a high level and declined significantly later in a manner similar to HCG. This discrepancy in the decline of 17-hydroxyprogesterone as opposed to progesterone and 17beta-estradiol may be explained by two mechanisms, the one mechanical, and the other secondary luteolytic. The marked increase of intrauterine pressure occurring within minutes after PGF2alpha instillation damages the fetoplacental unit. This leads to a decrease in the placental steroido-genesis and HCG production necessary for the maintenance of the corpus luteum.

Abortion, Induced↗

PubMed1980

Chorionic gonadotropin prevents LRF-agonist-induced luteolysis in the human.

The effects of exogenous and endogenous hCG on the luteolytic action of LRF-agonist, [D-Trp6, Pro9NEt]-LRF (LRF-Ag), were evaluated. In sequential studies, 4 normal cycling women treated with LRF-Ag (50 microgram S.C.) on two consecutive days had premature decline of circulating levels of progesterone (P) and estradiol (E2) with a shortened (p < 0.05) luteal phase (11.5 +/- 1.2 days) when compared to the control cycle (15 +/- 0.7 days). When intramuscular hCG was added to the LRF-Ag treatment in doses of 100 IU or 5000 IU daily for 7 days, the luteal function was prolonged (19 +/- 1.2 days, p < 0.05) with significant (p < 0.001) elevation of P and E2 levels compared with the control cycle. Four women with early pregnancy, requesting therapeutic abortion, were given LRF-Ag (50 microgram or 500 microgram S.C.) on 2 consecutive days. None of the 4 women aborted and there was no change in the levels of beta hCG, P or E2 over the course of a week. These results indicate that both exogenous or endogenous hCG can overcome the luteolytic effect of LRF-Ag within the dose and duration used. The possibility that a more prolonged administration of a larger dose of LRF-Ag may negate the luteotropic effect of hCG remains to be explored.

Chorionic Gonadotropin↗

PubMed1979

Estrone concentration in the peripheral plasma of pregnant and non-pregnant gilts.

A rapid radioimmunoassay for estrone (total unconjugated and sulfated) was developed to determine plasma estrone (E1) concentrations in inseminated gilts that conceived and those that had not. Thirty-one 160 day-old prepuberal gilts were induced to ovulate with gonadotropins and were artificially inseminated 10 hr before the expected time of ovulation (Day 1 - day of insemination). Unconjugated E1 and E1SO4 were extracted from 20 to 500 microl of plasma twice with 5 ml of tetrahydrafuran:ethyl acetate (1:1). Aliquots of a standard E1SO4 preparation were dissolved in 500 microl of distilled water and extracted at the same time as the plasma samples. The dried extracts were solvolyzed for 1 hr at 50 degrees C in 0.6 ml of glacial acetic acid:ethyl acetate (1:1), and the dried residue was redissolved in 0.2 ml of distilled water and extracted once with 2 ml of diethyl ether. Twenty of 31 gilts were pregnant at Days 29 to 31 of the induced cycle. Plasma E1 in pregnant gilts increased from 85 pg/ml on Day 18 to 702, 1879 and 2793 pg/ml, respectively, on Days 22, 25 and 29 to 31. Three of the non-pregnant gilts had plasma progesterone secretion maintained until Day 22; they also had a transitory increase in plasma E1 on Day 22 (215 pg/ml). Some blastocysts may have been present to exert a temporary luteotropic effect, but not enough blastocysts to completely overcome the luteolytic effect of the uterus. Quantification of plasma E1SO4 could be used as a pregnancy test in the pig.

Journal Article↗

PubMed1994

Modification of endometrial cell biology using progesterone antagonists to manipulate the implantation window.

The preimplantation effects of progesterone antagonists on the cell biology of the endometrium, corpus luteum function and interactions between these two organs have been studied. The antagonists lilopristone (ZK 98.734) and onapristone (ZK 98.299) were initially given per os to rabbits early or late in pseudopregnancy in combination with human chorionic gonadotrophin (HCG). These protocols were then modified to include hysterectomy or luteotrophic support with 17 beta-oestradiol. Given alone, the antagonists gave rise to endometrial regression (inhibition of epithelial proliferation and differentiation, increase of apoptosis). The simultaneous addition of oestradiol did not alter these findings. A rapid luteolysis occurred when the antagonists were given in late pseudopregnancy, but not if combined with oestradiol or hysterectomy. The endometrium was capable of renewal and of sustaining implantation if the corpora lutea survived or oestradiol was administered, and transferred blastocysts displayed normal implantation and normal embryonic development. These events did not occur when the antagonists were given during late pseudopregnancy without any steroid supplement. Progesterone antagonists can evidently exert a direct inhibitory effect on the endometrium, possibly with a later indirect luteolytic effect via endometrial mediators. Simultaneous addition of a proper luteotrophic signal results in corpora lutea which are refractory to lysis, so revealing a potential functional dissociation between endometrium and corpus luteum. The endometrium has the capacity to differentiate normally after an interrupted transformation and becomes receptive and sustains normal pregnancy, due to an expanded lifespan of the corpora lutea and a transposition of the implantation window. Uterine secretions from patients undergoing in-vitro fertilization, collected at the onset of the luteal phase, were evaluated by SDS-PAGE densitometry. The protein profiles gave indications of an adequate luteal phase pattern and of a receptive preimplantation phase. These results open the prospect of manipulating the human implantation window.

Animals↗

PubMed1992

Luteal control of endometrial receptivity and its modification by progesterone antagonists.

The objective of this study was to determine preimplantational effects of progesterone antagonists (PA) on the cell biology of the endometrium, on corpus luteum (CL) function and on the complex interactions between these two organs. The PA onapristone (ZK 98.299) or lilopristone (ZK 98.734) was given to pseudopregnant rabbits at days 5, 6, and 7 p.hCG. Three treatment protocols were investigated: Exp I, onapristone or lilopristone treatment only; Exp II, onapristone treatment after hysterectomy at day 1 p.hCG; Exp III, onapristone treatment together with 17 beta-estradiol, which represents the ultimate luteotropic hormone in the rabbit. In Exp I, onapristone and lilopristone gave rise to endometrial regression (inhibition of epithelial proliferation and differentiation, increase of apoptosis). Simultaneous addition of 17 beta-estradiol in Exp III did not alter these findings. A rapid luteolysis was found in Exp I. In Exp II and III, however, onapristone was unable to impair luteal development and function. Due to the unaffected CL in Exp III and due to the 17 beta-estradiol substitution, the endometrium was capable of starting a new transformation, which met all requirements for receptivity at day 12 p.hCG. Transfers of day 4 p.c. blastocysts from untreated donors into such delayed secretion recipient rabbits at days 12 p.hCG resulted in normal implantations and normal embryonic development. Contrary to Exp III, the missing of any luteotropic substitutions in Exp I resulted in a complete inhibition of further uterine transformation. The present findings suggest that PA can exert a direct inhibitory effect on the endometrium, which is followed by an indirect luteolytic effect via endometrial mediators. The simultaneous addition of a proper luteotropic signal to the PA protocol results in survival of CL. Furthermore, this prolongation of the CL life span can be interpreted as a functional dissociation of the endometrium from the CL.

Animals↗

PubMed1982

Effects of gonadotrophins, hypophysectomy and prostaglandin F-2 alpha on corpora lutea and ovarian follicles, and evidence for the presence of PGF-2 alpha receptors in the ovarian follicles and interstitium of non-pregnant guinea-pigs.

Simultaneous administration of hCG (but not FSH or prolactin) with PGF-2 alpha prevented the luteolytic effect of PGF-2 alpha after Day 9 of the oestrous cycle both morphologically and in terms of progesterone secretion in hysterectomized guinea-pigs. Hypophysectomy on Day 5 or PGF-2 alpha administration on Days 6--9 were not luteolytic, but their combined effect resulted in an advanced state of luteolysis as early as Day 9. When PGF-2 alpha was injected simultaneously with FSH or prolactin (but not hCG), the proportion of atretic antral follicles was significantly increased, although the total number of antral follicles remained unchanged. When PGF-2 alpha receptors were measured in the membrane fractions of luteal tissue and ovarian stromal, interstitial and follicular tissue obtained from cyclic animals, the concentrations were 22.75 and 36.26, and 62.60 and 96.26 fmol/mg membrane protein on Days 5 and 12, respectively. It is concluded that (1) LH protected corpora lutea against the luteolytic action of PGF-2 alpha up to Day 9 of the cycle, (2) PGF-2 alpha receptors were present in follicles, and (3) these receptors and PGF-2 alpha were involved in the development of the normal complement of Graafian follicles.

Animals↗

PubMed1985

LRFD6a has a dose-related stimulatory or inhibitory effect on the ovary in normal luteal phase women.

A dose response curve for LRFD6a-a potent LRF agonist-was established in normal midluteal phase women. At low doses (3-10 micrograms) an acute stimulatory effect on gonadotropins and ovarian steroidogenesis of estradiol and progesterone was observed. Despite large increases in circulating gonadotropins following the highest dose (30 micrograms LRFD6a), no acute changes in plasma steroids were noted. A sharp drop in progesterone was present after 3 days, with significant shortening of the cycle in 3 of 4 subjects in the group. While the stimulatory effect may be due to gonadotropin release and local action, the luteolytic effect observed is suggested to be a consequence of the direct inhibitory effect of the analog on ovarian function.

Adult↗

PubMed1978

[Postcoital contraception in primates. I. Action mechanism of a potential postovulatory fertility-inhibiting substance STS 456 in the baboon (Papio hamadryas)].

With the substance STS 456, an estrogenic active steroid, a high fertility inhibition could be obtained in the pavian, when administered p. o. over a 5 day period postcoital. The effectiveness and also the side effects were dose dependent. The antifertility mechanism is based on an luteolytic effect, demonstrated by analytical hormonal investigations. The inhibition of the synthesis of steroids in the ovary affected not only progesterone but also the estrogens.

Animals↗

PubMed1979

Functional luteolysis in the pseudopregnant rat: effects of prostaglandin F2 alpha and 16-aryloxy prostaglandin F2 alpha in vitro.

The present work concerns the luteolytic effects of prostaglandin (PG) F2 alpha and its analogue, 16-aryloxy PGF2 alpha, upon isolated luteal cells. Varying doses of these two prostaglandins were incubated with cells in the presence or absence of an optimum stimulatory dose of LH (1 microgram/ml). The total contents of progesterone and 20 alpha-dihydroprogesterone in flasks were determined after the incubation periods by radioimmunoassay. Both prostaglandins inhibited basal synthesis of progesterone and 20 alpha-dihydroprogesterone, maximum inhibition occurring at concentrations of either PG of between 250 and 500 ng/ml. In this dose range both prostaglandins were found to abolish LH-stimulated progestogen synthesis completely. These effects were discernible within 5 min of incubation. The studies demonstrated that the onset of PG-induced luteolysis in vitro is characterized by an inhibition of the biosynthesis of both progesterone and its weakly progestogenic metabolite, 20 alpha-dihydroprogesterone; induction of 20 alpha-hydroxysteroid dehydrogenase activity by either PG was not found in incubations extending up to 60 min. In contrast to their relative potencies in vivo, PGF2 alpha and 16-aryloxy PGF2 alpha were essentially equipotent in this in-vitro system.

20-alpha-Dihydroprogesterone↗