共查询到20条相似文献,搜索用时 31 毫秒
1.
Ray V. Haning Jr. Leslie Choi Amber J. Kiggens Donna L. Kuzma John W. Summerville 《Prostaglandins & other lipid mediators》1982,23(1):29-40
Explants from term human placentas were maintained in culture with daily changes of medium. Daily output of PGF2α and PGFM1 decreased during the course of the incubation. Addition of 4 μg/ml DHEAS or 67 μg/ml LDL cholesterol had no effect on output of PGF2α or PGFM. Addition of 1.6, 3.2, or 6.4 μg/ml of LHRH to the culture plates had no effect on output of PGFM or PGF2α, but LHRH increased hCG output. Dibutyryl cAMP (1mM, 2mM, and 4mM) increased output of PGF2α, PGFM, and hCG. Aromatase inhibitor decreased hCG output, but it was without effect on output of PGF2α, or PGFM. Significant correlations were demonstrated between progesterone, PGFM, PGF2α, and hCG, suggesting that PGF2α originates in the syncytiotrophoblast cell. The ability of LHRH to stimulate output of hCG but not PGF2α while dbcAMP stimulated both suggests that either PGF2α and hCG arise in different cells or that LHRH does not act through cAMP. 相似文献
2.
In order to compare the endocrine response of placental minces to luteinizing hormone releasing hormone (LHRH) and dibutyryl cAMP (dbcAMP) and to screen for effects of potential stimulatory and inhibitory substances, the simultaneous outputs of PGF2 alpha, 13, 14-dihydro-15-keto-prostaglandin F2 alpha (PGFM), progesterone, 17 beta-estradiol, and hCG were evaluated during a 4 hour incubation in 5 placentas. The output of hCG was highest for 12-week placentas, intermediate for a 16 week placenta, and lowest for term placentas. The output of 17 beta-estradiol by 12 and 16 week placentas in the presence of 30 microM dehydroepian-drosterone sulfate (DHEAS) was greater than that by term placentas. Progesterone output was apparently independent of gestational age although some variation between 12-week placentas was demonstrated. Output of PGF2 alpha was lower in 12 and 16-week placentas than in term placentas and that of PGFM was lower in 12-week placentas than in term placentas. LHRH (100 nM) produced stimulation of PGF2 alpha output (P less than .005) and a trend toward inhibition of progesterone output (which failed to achieve statistical significance) but no stimulation of hCG under these conditions. Stimulation of the outputs of hCG (P less than .005) and PGF2 alpha (P less than .001) and inhibition of that of progesterone (P less than .005) was produced by 20 mM dbcAMP. DHEAS inhibited output of progesterone (P less than .01) and PGF2 alpha (P less than .01). There were no effects of potassium, estrogens, progesterone, or prostaglandins on output of any measured substance. 相似文献
3.
The effect of prostaglandin PGF2α on the hCG stimulated and basal progesterone production by human corpora lutea was examined
. hCG (40 i.u./ml) stimulated progesterone formation in corpora lutea of early (days 16–19 of a normal 28 day cycle), mid (days 20–22) and late (days 23–27) luteal phases. This stimulation was inhibited by PGF2α (10 μg/ml) in corpora lutea of mid and late luteal phases. PGF2α alone did not show a consistent effect on basal progesterone production. The inhibition of hCG stimulated progesterone production by PGF2α at times corresponding to luteolysis indicates a role for that prostaglandin in the process of luteolysis in the human corpus luteum. 相似文献
4.
C.H. Spilman D.C. Beuving A.D. Forbes F.A. Kimball 《Prostaglandins & other lipid mediators》1977,14(3):477-488
The effects of prostaglandin (PG)F2α and PGF2α, 1–15 lactone were compared in luteal phase, non-pregnant and in early pregnant rhesus monkeys. Animals treated with either PG after pretreatment with human chorionic gonadotropin (hCG) had peripheral plasma progesterone concentrations that were not statistically different from those in animals treated with hCG and vehicle. However, menstrual cycle lengths in monkeys treated with PGF2α, 1–15 lactone were significantly (P <0.02) shorter than those in vehicle treated animals. In the absence of hCG pretreatment, plasma progesterone concentrations were significantly (P <0.008) lower by the second day after the initial treatment with either PGF2α or PGF2α, 1–15 lactone than in vehicle treated monkeys. Menstrual cycle lengths in monkeys treated with either PG were significantly (P <0.04) shorter than those in animals treated with vehicle. There were no changes in plasma progesterone concentrations in early pregnant monkeys treated with PGF2α, and pregnancy was not interrupted. In contrast, plasma progesterone declined and pregnancy was terminated in 5 of 6 early pregnant monkeys treated with PGF2α, 1–15 lactone. These data indicate that PGF2α, 1–15 lactone decreases menstrual cycle lengths in non-pregnant rhesus monkeys. More importantly, PGF2α, 1–15 lactone terminates early pregnancy in the monkey at a dose which is less than an ineffective dose of PGF2α. 相似文献
5.
H. D. Hafs T. M. Louis R. J. Waters J. N. Stellflug N. B. Haynes 《Prostaglandins & other lipid mediators》1974,8(5):417-422
Seven rabbits were ejaculated four times once weekly, and saline or 2.5 mg PGF2α tromethamine salt was injected sc at 4 and 2 hours or at 8 and 4 hours before ejaculation. First ejacula taken at 2 hours after the second injection of PGF2α contained 150% more (P.07) sperm than those after injections of saline. The comparable difference (60%) at 4 hours after PGF2α was not significant. PGF2α did not influence sperm output in second, third or fourth ejacula. After 28 daily sc injections of 5 mg PGF2α in another experiment, the fertility of four treated rabbits was as high as that for four controls. Without sexual preparation in seven bulls, im injections of 40 or 80 mg PGF2α 30 minutes before ejaculation resulted in 33% greater (P<.05) sperm output than that after injection of 0, 7 or 20 mg PGF2α, but the highest sperm output after PGF2α was 30% less (P<.05) than that after sexual preparation in the same bulls. We conclude that injections of PGF2α result in increased sperm output in ejacula taken without sexual preparation within 2 hours in rabbits and in bulls. 相似文献
6.
Y.S. Weems D.L. Vincent K.D. Nusser Y. Tanaka K. Miller-Patrick K.S. Ledgerwood C.W. Weems 《Prostaglandins & other lipid mediators》1993,46(3)
Vehicle or 8 or 16 mg of PGF2α per 58 kg body weight was given intramuscularly to intact, hysterectomized or ovariectomized 90–100 day pregnant ewes in three separate experiments. Both doses of PGF2α increased PGF2α in ovarian venous plasma compared with controls at 72 hr post treatment in intact (P≤0.05) but did not in hysterectomized (P≥0.05) 90–100 day pregnant ewes. Concentrations of PGE in ovarian venous blood of intact ewes did not differ (P≥0.05) between treatment groups and were equivalent to concentrations of PGE determined in uterine venous plasma. PGE was decreased in ovarian venous plasma by PGF2α in hysterectomized ewes (P≤0.07). PGE in uterine venous plasma averaged 6 ng/ml over the 72-hr treatment period in intact and ovariectomized 90–100 day pregnant ewes and was 12 fold greater (P≤0.05) than PGF2α which averaged 500 pg/ml in uterine venous plasma. Both PGF2α and PGE increased (P≤0.05) by 64 hr in uterine venous plasma of the 8 mg PGF2α — treated intact pregnant ewes. A significant quadratic increase (P≤0.05) was observed for PGF2α and PGE in the vehicle and both PGF2α treatment groups of intact ewes at the end of the 72-hr sampling period. It is concluded that the uterus and ovaries secrete significant quantities of PGE but little PGF2α during midgestation. In addition, PGF2α increased uterine secretion of PGE
. PGE may be a placental stimulator of ovine placental secretion of progesterone or PGE may protect placental steroidogenesis from actions of PGF2α. 相似文献
7.
J.J. Knickerbocker W.W. Thatcher F.W. Bazer D.H. Barron R.M. Roberts 《Prostaglandins & other lipid mediators》1986,31(4)
The effect of bovine conceptus secretory proteins (CSP) on uterine prostaglandin (PG)-F2α production was evaluated in dairy cattle following injection of estradiol-17β. Intrauterine injections of dialyzed serum proteins (Control, n=5) or CSP (n=5) were administered from days 15 through 18 post-estrus. Following intrauterine treatments on day 18, all cows were injected with E2 (3 mg) to stimulate uterine PGF2α production. Plasma concentrations of progesterone (P4) and 15-keto-13,14-dihydro-PGF2α (PGFM) were determined by RIA. The PGFM responses following E2 challenge were decreased (p<0.01) for cows receiving CSP versus serum proteins into the uterine lumen. Individual PGFM, P4 and cycle length responses are discussed. Data suggest that proteins secreted by the bovine conceptus suppress uterine PGF2α production during pregnancy recognition in the cow. 相似文献
8.
John W. Wilks 《Prostaglandins & other lipid mediators》1977,13(1):161-170
The naturally-occurring metabolite of prostaglandin F2α, 15-keto prostaglandin F2α (15-keto PGF2α), elicited rapid and sustained declines in serum progesterone concentrations when administered to rhesus monkeys beginning on day 22 of normal menstrual cycles. Evidence for luteolysis of a more convincing nature was obtained in studies where a single dose of 15-keto PGF2α was given on day 20 of ovulatory menstrual cycles in which intramuscular injections of hCG were also given on days 18–20; serum progesterone concentrations fell precipitously in monkeys within 24 hours following intramuscular administration of 15-keto PGF2α. However, corpus luteum function was impaired in only 4 of 11 early pregnant monkeys when 15-keto PGF2α was administered on days 30 and 31 from the last menses, a time when the ovary is essential for the maintenance of pregnancy. Gestation failed in 2 additional monkeys 32 and 60 days after treatment with 15-keto PGF2α, but progressed in an apparently normal manner in the remaining 5 animals. Two pregnant monkeys treated with 15-keto PGF2α on day 42 from the last menstrual period, a time when the ovary is no longer required for gestation, continued their pregnancies uneventfully. Corpus luteum function was not impaired in 9 control monkeys which received injections of vehicle or hCG at appropriate times during the menstrual cycle or pregnancy. 相似文献
9.
F.J. Auletta D.L. Kamps M. Wesley M. Gibson 《Prostaglandins & other lipid mediators》1984,27(2):299-310
The role of prostaglandin F2α (PGF2α) in luteolysis in the non-human primate is poorly understood. We have recently reported that chronic PGF2α infusion to the corpus luteum via Alzet pump, induced premature, functional luteolysis in the rhesus monkey. In the present study we sought to determine the ovarian events leading to spontaneous luteolysis in the monkey. Rhesus monkeys underwent laparotomy during the early luteal (4–5 days after the preovulatory estradiol surge, PES), mid-luteal (7–9 days PES), and late luteal (10–14 days PES) phases or at the first day of menses (M). Concentrations of progesterone, estradiol, estrone, and 13, 14-dihydro-15-keto-PGF2α (PGFM) were measured in the ovarian venous effluents ipsilateral and contralateral to the ovary bearing the corpus luteum. Steroid levels in the ovarian vein on the corpus luteum side were significantly higher than the non-corpus luteum side throughout the cycle. PGFM levels were similar on both sides until the late luteal phase, when the effluent of the ovary bearing the corpus luteum contained significantly more PGFM (206±3) vs. 123±9 pg/ml, mean±sem); this disparity increased further at the time of menses (241±38 vs. 111±22 pg/ml). These data are the first to show an asymmetric secretion of PGFM in the ovarian venous effluent in the primate and suggest that PGF2α of ovarian and possibly of corpus luteum origin may be directly involved in luteal demise. 相似文献
10.
P.H. Hemsworth J. Donnelly J.K. Findlay D.B. Galloway 《Prostaglandins & other lipid mediators》1977,13(5):933-941
The effect of prostaglandin F2α (PGF2α) on the sperm output of six boars was investigated in two studies. Although PGF2α did not significantly affect sperm numbers in the ejaculate, a significantly longer (P < 0.05) ejaculation of the sperm rich fraction occurred following injection of PGF2α. In the second study it was found that PGF2α produced a 49% increase (P < 0.05) in the number of sperm in the sperm rich fraction of the ejaculate. The implications of these results on artificial breeding are discussed. 相似文献
11.
The uterus of six healthy multiparous women at term was mechanically stretched by a rubber catheter and balloon. Apparent labor was inaugurated in all cases within 5 hours and increased progressively with time. Advanced cervical softening and dilatation were also evident after the stretch treatment. Significant increases in the levels of 13,14-dihydro-15-keto-prostaglandin F2α (PGFM) were observed with the progress of treatment (P < 0.01). Plasma estrogens and progesterone levels did not change significantly during the treatment (P > 0.05). Stretching and/or resulting uterine contractions appear to induce the secretion of prostaglandin F2α (PGF) from the organ, which in turn seems to be involved in both cervical softening, and the onset and progress of labor, under stable conditions of plasma estrogens and progesterone. 相似文献
12.
The mechanism of stimulatory and inhibitory action of PGF2α on ovarian steroidogenesis both under
and
conditions has been studied in the pseudo-pregnant rabbits. Short term incubation of the ovaries with PGF2α (2.82 × 10−5M) resulted in an increased synthesis of progesterone and 20α-OH P. The addition of PGF2α in the medium and further incubation of the ovaries obtained from rabbits that had been constantly infused with PGF2α (0.5 μg/min.) for two hours resulted in increased synthesis of these progestins. The ratio of progesterone to 20α -OH P was also enhanced under these conditions and thus supported the luteotropic action of small doses of PGF2α under short term incubations. However, as the amount of PGF2α infused was increased to 5 μg/min., the addition of PGF2α under
conditions strikingly decreased the production of these progestins. The ratio of progesterone to 20α -OH P was also decreased and thus was indicative of luteolytic action of higher doses of PGF2α. High doses of PGF2α (5.64 × 10−4M) failed to I cause any significant change in the progestin synthesis under short term incubation. These results thus suggest that the luteotropic and luteolytic action of PGF2α in the luteinized rabbit ovary is dose and time dependent. 相似文献
13.
Ian Craft Elizabeth Walker Ezat Youssefnejadian 《Prostaglandins & other lipid mediators》1974,5(4):397-407
Prostaglandin F2α (PGF2α) 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 PGF2α is given alone and 2 patients had small cervical lacerations requiring suture. Further studies are indicated to establish whether a lower dose of PGF2α will be associated with fewer side effects and be as effective. 相似文献
14.
Prostaglandin F2α (PGF2α) was measured by immunoassay in plasma and milk of four cows (six experiments). After 30 mg PGF2α im, plasma PGF2α peaked at 15 minutes (2.4 ± 0.7 ng/ml) and declined toward basal values by 3 hours; maximum milk PGF2α (0.91 ± 0.12 ng/ml) occurred at 1 hour. The average excretion rate in milk was 2.9 μg/day 0.9 μg (0.003%) of which was due to the 30 mg PGF2α injected. In six non-pregnant control cows, daily changes of milk PGF2α and progesterone were not consistently related. 相似文献
15.
Shiro Ohki Katsuhiro Imaki Fumio Hirata Toshio Hanyu Nobuhiko Nakazawa 《Prostaglandins & other lipid mediators》1974,6(2)
Radioimmunoassays for measuring prostaglandin F2α (PGF2α) and 5α, 7α-dihydroxy-11-keto tetranorprosta-1,16-dioic acid, PGF2α-main urinary metabolite (PGF2α-MUM), with 125I-tyrosine methylester amide (TMA) of PGF2α and PGF2α-MUM were developed.Antibody to PGF2α was produced in rabbits immunized with conjugates of PGF2α coupled to bovine serum albumine. Antibody to PGF2α-MUM was also produced in rabbits immunized with conjugates of PGF2α-MUM coupled to bovine serum albumin.PGF2α-125I-TMA had an affinity to antiserum to PGF2α. PGF2α-MUM-125I-TMA also responded to antiserum to PGF2α-MUM. 相似文献
16.
Induction of 20α-hydroxysteroid dehydrogenase in rat corpora lutea of pregnancy by prostaglandin F2α
20α-OH-SDH is a marker of luteolysis in rat corpora lutea and appearance of this enzyme is inhibited by prolactin but stimulated by LH or hCG. PGF2α induced 20 α-OH-SDH activity in corpora lutea of pregnant rats and a significant fall in peripheral plasma progesterone concentrations when administered i.m. for two consecutive days. Rats treated with PGF2 α on days 8 and 9 of pregnancy were resorbing implants by day 10. Exogenous progesterone, but not estrogen, prevented implant resorption, yet 20 α-OH-SDH appeared in the corpora marking luteolysis. HCG, LH and prolactin, but not FSH, prevented pregnancy termination and inhibited induction of 20 α-OH-SDH in rats treated with PGF2 α in early pregnancy. PGF2α also induced 20α-OH-SDH in luteal tissue of intact and hypophysectomized rats treated on days 14 and 15 of pregnancy, but neither exogenous steroids or gonadotrophins blocked the induction of the enzyme in rats treated at this time. The increase in lutein 20α-OH-SDH activity during the peripartal period was partially blocked by administration of the prostaglandin biosynthesis inhibitor, indomethacin, suggesting a role for endogenous prostaglandins in the induction of 20α-OH-SDH at term. It appears that PGF2α acts directly on the ovary to induce 20α-OH-SDH activity by preventing the luteotrophic action of prolactin. Other luteal NADPH-dependent dehydrogenase activities are not markedly stimulated following PGF2α administration. 相似文献
17.
M. Duchens H. Kindahl M. Forsberg H. Gustafsson H. Rodríguez-Martínet 《Animal reproduction science》1995,40(4):261-268
A study was conducted to determine the effect of suprabasal plasma concentrations of progesterone on the release of prostaglandin F2α (PGF2α) at luteolysis and oestrus. Heifers received silicone implants containing 2.5 (n = 4), 5 (n = 4), 6 (n = 3), 7.5 (n = 3), 10 (n = 4), or 15 (n = 3) g of progesterone, or an empty implant (controls, n = 4) between Days 8 and 25 post ovulation. Blood was collected frequently between Days 14 and 28 and assayed for progesterone and 15-ketodihydroprostaglandin F2α. Basal progesterone concentrations in control heifers did not differ from those in heifers with 2.5- or 5-g implants and remained around 0.4−0.5 nmol l−1 until ovulation in all three groups. In the heifers treated with 6–15 g of progesterone, basal concentrations were maintained at higher (P < 0.05) levels compared with those in the controls, ranging from 0.8 to 1.6 nmol 1−1. The effect of these elevated progesterone levels was to delay ovulation by prolonging the growth of the ovulatory follicle, which continued growing until the implant was removed. In all experimental groups, the first significant increase of the PGF2α metabolite occurred between Days 15.3 and 16.3 (P > 0.05) and was associated with the onset of a decrease in progesterone concentrations, which had reached levels below 3 nmol 1−1 by Days 17.4−19.1. PGF2α metabolite peaks associated with luteolysis were frequent until Day 20. In the period from Day 20 until implant removal, sporadic peaks were observed, ranging in number from 1.0 ± 1.2 (mean ± SEM) in the control group to 3.0 ± 1.4 peaks in the heifers treated with 7.5 g of progesterone (P > 0.05). The number of PGF2α metabolite peaks during that period was higher (P < 0.05) in heifers treated with 10 and 15 g than in controls. A positive correlation was found between the basal concentration of progesterone and the number of PGF2α peaks after luteolysis (r = 0.54; P < 0.01). Plasma progesterone concentrations above approximately 1.4 nmol l−1 were able to maintain the release of PGF2α until the progesterone implants were removed and plasma levels decreased to basal values. These heifers had a preovulatory PGF2α release pattern resembling that found in repeat breeder heifers. 相似文献
18.
Peripheral plasma concentrations of 13,14-dihdyro-15-keto-prostaglandin F2α (PGFM) and progesterone were determined during both luteolysis in the oestrous cycle and early pregnancy in four goats. Luteal regression, characterised by decreasing progesterone concentrations, began on day 12 or 13. PGFM concentrations showed a pulsatile pattern around this time, with peak concentrations increasingly markedly as progesterone levels fell and oestrus approached. During early pregnancy progesterone concentrations did not fall after day 12 and no marked elevation of PGFM above basal values of 50–150 pg/ml was detected. 相似文献
19.
The temporal relationships between a pulse of 13,14-dihydro-15-keto-PGF2α (PGFM) and the concentrations of circulating hormones during the luteolytic period were studied for 11 pulses in 11 mares (Equus caballus) using samples collected hourly. Mean PGFM pulses encompassed 4 h before to 4 h after the peak, and hormone data were normalized to the PGFM peak (Hour 0). Concentration of progesterone decreased (P < 0.05) between Hours –4 and –3 and continued to decrease linearly throughout the PGFM pulse. The concentrations of cortisol and prolactin increased (P < 0.004) during Hours –4 to 0 and decreased (P < 0.002) during Hours 0 to 4. Estradiol concentration increased (P < 0.02) during Hours –4 to 0 but did not change significantly after Hour 0. Concentrations of follicle-stimulating hormone and luteinizing hormone did not change significantly during the PGFM pulse, and the oxytocin results were equivocal. Percentage of corpus luteum area with color-Doppler signals of blood flow did not change significantly between Hours –4 and 0 and first began to decrease (P < 0.004) between Hours 0 and 2. Results demonstrated that concentrations of progesterone decreased linearly during a PGFM pulse, and cortisol, prolactin, and estradiol increased during the ascending portion of the pulse. The progesterone and gonadotropin results supported the hypothesis that the initial progesterone and gonadotropin increases that have been reported to occur in response to a single bolus luteolytic treatment with prostaglandin F2α do not occur in response to the natural secretion of prostaglandin F2α. 相似文献
20.
Martin Hichens Daniel L. Grinwich Harold R. Behrman 《Prostaglandins & other lipid mediators》1974,7(6):449-458
In experiments
and
we have previously shown that PGF2α directly antagonized the action of gonadotrophins on the corpus luteum. To determine if this action of PGF2α may occur as a consequence of an induced loss of gonadotrophin receptors, binding of hCG to rat luteal tissue was measured following PGF2α treatment
. In immature rats which were treated with exogenous gonadotrophin to luteinize the gonads, PGF2α produced a marked and highly significant decrease in circulating progesterone when administered 24 hours before sacrifice. Although the affinity constant (Ka; 1.2-2 × 1010 L/M) of the luteal receptor to hCG was not affected, PGF2α treatment produced a marked fall in the binding capacity of the luteal tissue to hCG. This response was absent, however, when PGF2α was incubated directly with luteal receptor or administered during early pseudopregnancy when corpora lutea are more resistant to luteolysis. Experiments are in progress to determine if the decrease in capacity of luteal receptors to bind hCG is the mechanism or a consequence of luteolysis produced by PGF2α. 相似文献