Comparison of oxytocin/prostaglandin F-2 alpha interrelationships in cyclic and pregnant cows

The secretion of prostaglandin (PG) F-2 alpha in response to intravenous injection of 100 i.u. oxytocin on Day 18 after oestrus was determined by measuring jugular venous concentrations of 13,14-dihydro-15-keto PGF-2 alpha (PGFM) in 7 pregnant, 6 cyclic and 2 inseminated non-pregnant heifers. Two other heifers received i.v. saline (controls). The immediate responses of pregnant heifers were smaller than in non-pregnant animals (P less than 0.05), as were baseline concentrations in the post-response period (P less than 0.05). Endometrial oxytocin receptor concentrations were higher in nonpregnant than pregnant heifers (P less than 0.05), but PGFM response to oxytocin challenge was not correlated with oxytocin receptor concentration. Oxytocin receptor concentrations on Day 18 were positively correlated with those of plasma oestradiol on Day 17 (P less than 0.01) and inversely with plasma progesterone concentrations on Day 18 (P less than 0.01). These findings confirm that PGF-2 alpha secretion in response to oxytocin challenge is attenuated in pregnant animals on the 18th day after oestrus and that, while the prevailing steroid environment is of importance in inducing oxytocin receptor activity, the secretion of PGF-2 alpha is not subsequently limited by oxytocin receptor numbers. The quantities of PGE-2, PGFM and PGF-2 alpha recovered in uterine flushings taken from heifers on Day 18 were greater in pregnant than other animals (P less than 0.01, P less than 0.05, P less than 0.001, respectively). Intrauterine concentrations of PGF-2 alpha and PGFM were not correlated with the plasma PGFM responses.

Prostaglandin production by the largest preovulatory follicles in the domestic hen (Gallus domesticus)

An injection of 5 micrograms of gonadotropin-releasing hormone (GnRH) into hens 8 h prior to oviposition advanced the expected time of oviposition by approximately 1 h. The plasma concentration of progesterone increased approximately 1 h earlier in GnRH-injected hens in comparison to saline-injected hens. The plasma concentration of 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) increased significantly (p less than 0.05) at the time of oviposition in both the GnRH- and saline-injected hens. Significantly (p less than 0.05) greater concentrations of prostaglandin F2 alpha (PGF2 alpha) were assayed in media containing the largest preovulatory follicles collected at oviposition than in media containing the second and fifth largest preovulatory follicles collected at the same time. No prostaglandin was detected in media containing small, nonhierarchial follicles. The concentration of PGF2 alpha in media containing granulosa cells from the largest preovulatory follicle was significantly greater (p less than 0.05) than in media containing 4 times as many theca cells. Ovine luteinizing hormone (oLH) alone or in combination with arachidonic acid had no effect on PGF2 alpha output from granulosa cells collected 6 h before oviposition, whereas A23187 caused a small stimulation of PGF2 alpha output. However, treating cells first with oLH and then with A23187 stimulated a 15- to 20-fold increase in PGF2 alpha. None of these stimuli enhanced the already high output of PGF2 alpha when added to incubations of granulosa cells collected within 5 min after oviposition. These data suggest that the granulosa cells of the largest preovulatory follicle are the major intraovarian source of prostaglandin and that production of PGF2 alpha is associated with the preovulatory surges of gonadotropins and steroid hormones preceding oviposition.

Prostaglandins: PGF2 alpha, PGE2, 6-keto-PGF1 alpha and TXB2 serum levels in dysmenorrheic adolescents before, during and after treatment with oral contraceptives

Ten adolescents with primary dysmenorrhea (PD) were treated with the oral contraceptive (OC) Lyndiol 2.5 mg (R) for one cycle. The levels of PGF2 alpha, PGE2 and the metabolites of PGI2 and TXA2: 6-keto-PGF1 alpha and TXB2 were tested by a radioimmunoassay method during the 1st and 23rd day of the pre-treatment cycle (PrTC), the 23rd day of treatment (TC) and the 1st day of the post-treatment cycle (PoTC). The ratios PGF2 alpha/PGE2 and TXB2/6-keto-PGF1 alpha were also tested and compared during the above-mentioned days. Analytical comparison was made, for each Prostaglandin (PG) separately, between the 1st day of the PrTC and PoTC as well as the 23rd day of the PrTC and TC, respectively. All PG levels during TC and PoTC were found significantly lower, compared to those of the PrTC respectively. With regard to the ratios mentioned above, no statistically significant differences were found on the same days and cycles as previously stated. The reduction of the PG levels in PD patients after treatment with oral contraceptives, together with an improvement of the clinical findings of the disease, support the theory that oral contraceptives can be used for the treatment of PD cases, especially for those adolescents who also desire a contraceptive method.

Administration of pig relaxin to beef heifers 4 or 7 days pre partum

Crossbred beef heifers (N = 36) were assigned to one of three treatment groups: untreated controls (C; N = 15); Group R4, treated with pig relaxin (1.0 mg i.m.) 4 days pre partum (N = 11); or Group R7, treated with pig relaxin (1.0 mg i.m.) 7 days pre partum (N = 10). Bioactivity of the pig relaxin (UMC-R-P8) was determined by the mouse interpubic ligament assay to be greater than or equal to 3000 U/mg, both before and after the experiment was conducted. Peripheral serum immunoreactive relaxin values were 7.5, 3.4, 2.5, and 1.5 ng/ml at 2, 4, 6 and 8 h after injection of relaxin, respectively. Gestation lengths were 282.9 +/- 1.1, 285.5 +/- 1.3 and 285.6 +/- 1.5 days for Groups C, R4 and R7 (C vs R4 + R7; P congruent to 0.08). Calving difficulty score (1 to 4) tended to be greater (P congruent to 0.08) for Group R4 and R7 heifers (C vs R4 + R7; 1.3 +/- 0.24 vs 1.75 +/- 0.28 + 2.04 +/- 0.32), but the incidences of dystocia and retained placentae were not influenced by treatment (P greater than or equal to 0.10). The mean concentration and concentration profile of daily serum progesterone, oestradiol-17 beta, dihydroprostaglandin F-2 alpha and relaxin were not affected by treatment from 6 days pre partum through 2 days post partum. Cervical diameter, cervical softness score, pelvic measurements, and vulva opening length during the periparturient period were not affected (P greater than or equal to 0.10) by treatment, but all of these characteristics changed over time (P less than or equal to 0.01), relative to calving. We conclude that i.m. administration of pig relaxin (greater than or equal to 3000 U) does not effectively alter periparturient characteristics of beef heifers. Discrepancies between these results and those reported for intracervical administration cannot be readily explained.

A time-resolved fluoroimmunoassay for the determination of prostaglandin F2 alpha

We describe a solid-phase immunoassay based on fluorescence detection for Prostaglandin F2 alpha (PGF2 alpha). Europium was used as the fluorescence marker. Prostaglandin F2 alpha was covalently bound to poly-L-lysine (PL) and labelled by coupling Eu3+ via the complexonate diethylenetriaminepentaacetic acid (DTPA). The labelled PGF2 alpha was tested in a competitive immunoassay. The detection limit for PGF2 alpha was about 2.2 pg per microtiter well. The intraassay-variation was 17.2% at 1.1 pg, 4.1% at 10 pg and 7.6% at 90 pg. The precision was determined by measuring various amounts of unlabelled PGF2 alpha (2.5 to 2,400 pg) in the assay buffer. The regression line for these studies resulted in a good correlation (y = 1.01x +/- 0.03; r = 0.996; n = 21). The results of a radioimmunoassay and of the fluoroimmunoassay were similar (y = 0.983 +/- 0.04; r = 0.988; n = 15). The new method enables PGF2 alpha analyses at concentrations in the fmolar range.

Plasma elevations of histamine and a prostaglandin metabolite in acute bronchiolitis

Acute bronchiolitis (AB) is a common lung disease in infants manifested clinically by dyspnea and wheezing. The purpose of this study was to measure simultaneous plasma levels of histamine and a stable prostaglandin F2 alpha metabolite [13,14-dihydro-15-keto-PGF2 alpha (PG metabolite)], by radioenzymatic and radioimmunoassays, respectively, during and after recovery from AB. Blood was obtained from 15 infants during AB and from 14 and 9 of these infants when re-evaluated 6 and 18 months later, respectively. Mean (+/- 1 SEM) pre- and posttherapy (inhaled isoetharine) histamine levels (pg/ml), 1,923 +/- 980 and 1,035 +/- 250 during AB, respectively, were markedly higher than those of the same nonwheezing subjects at 18 months, 360 +/- 125, but unexpectedly lower than those at 6 months, 9,210 +/- 5,242. Of the 14 infants evaluated at 6 months, 7 had elevated histamine levels along with histories of recurrent wheezing after AB. Similarly, pre- and posttherapy PG metabolite levels (pg/ml), 1,033 +/- 419 and 1,613 +/- 527, respectively, were significantly higher than those of the same children when asymptomatic at 6 (27 +/- 7) and 18 months (68 +/- 25). Pre- and posttherapy levels of histamine and PG metabolite were higher than those of normal and sick, nonwheezing infants. These data indicate that histamine and PG metabolite are detectable in plasma during AB and suggest a role for histamine and PGF2 alpha in the pathogenesis of airways inflammation in AB.

Levels of 15-ketodihydroprostaglandin F2 alpha during experimental Toxoplasma gondii infection in non-pregnant ewe lambs

In order to study the relation between prostaglandin F2 alpha levels and fever during Toxoplasma gondii infection, six non-pregnant ewe lambs were exposed orally to T. gondii oocysts and an additional four animals were used as non-inoculated controls. Rectal temperature was measured daily during four weeks and plasma samples were analysed for the content of 15-ketodihydroprostaglandin F2 alpha. As compared to controls, the inoculated animals had significantly elevated rectal temperatures on days 4-16 after infection, but no concomitant changes in prostaglandin F2 alpha metabolite levels were recorded.

Associations among progesterone, estradiol-17 beta, oxytocin and prostaglandin in cattle treated with hCG during diestrus to extend corpus luteum function

Treatment of cattle during the middle of the luteal phase with appropriate doses of human chorionic gonadotropin (hCG) causes a 5 d extension of the estrous cycle. Three experiments were conducted to determine how treatment with hCG affected the pattern of secretion of prostaglandin F2 alpha, as indicated by blood levels of 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM). In experiment 1, Holstein cows were given saline (Sal) or hCG (10,000 IU, im) on d 10 of the estrous cycle and blood samples were collected over a 6 h period on d 14 and 18 during which oxytocin (10 and 100 IU, iv) was given at 2 and 4 h. Concentrations of PGFM before and after oxytocin were similar between Sal and hCG-cycles, but PGFM was higher on d 18 than d 14 (P less than 0.05). In experiment 2, episodic PGFM was measured from d 16 to 20 in cows given Sal or hCG on d 10. There was tendency for hCG to reduce PGFM baseline and pulse amplitude (P = 0.22). In experiments 1 and 2, estradiol increased during d 16 to 20 of Sal-cycles, but did not change during this period of hCG-cycles. Therefore, in experiment 3, Holstein heifers were given Sal or hCG (5000 IU, im) on d 10, followed by corn oil (Oil) or estradiol benzoate (EB; 200 micrograms, im, 2X/day) on d 15 to 18. No difference in progesterone secretion was observed between Sal-Oil and Sal-EB heifers; however, EB hastened luteolysis in hCG-treated heifers (P less than 0.05), without causing an increase in PGFM. Although subtle differences were seen in pulsatile PGFM, we conclude that hCG altered the pattern of estrogen secretion, and this led to delayed luteolysis.

[Effects of danggui shaoyao powder on blood rheological indexes and prostaglandin F2 alpha in dysmenorrhea patients]

The results showed that several blood rheological indexes of dysmenorrhea patients were abnormal, the contents of plasma prostaglandin F2 alpha (PGF2 alpha) and menstrual blood PGF2 alpha of the patients were significantly higher than those of the normal women. The abnormal indexes were recovered to normal range after the patients had been treated with Danggui Shaoyao Powder for 3 months. Danggui Shaoyao Powder had better actions of improving the abnormal indexes than Tianqi Dysmenorrhea Capsule did.

The physiological and clinical effects of progesterone inhibition with mifepristone (RU 486) in the second trimester

A double-blind placebo-controlled trial was performed in 20 primigravidae to assess the physiological and clinical effects of oral mifepristone on myometrial contractility and sensitivity in the second trimester. Ten women received 600 mg of oral mifepristone and 10 women a placebo 24 h before abortion was induced in both groups, with extra-amniotic PGE2 instillation. Intrauterine pressure recordings demonstrated increased spontaneous uterine activity and increased sensitivity to PGE2 and ergometrine, but no change in oxytocin sensitivity after mifepristone treatment. There were no significant differences in PGE or PGF metabolite concentrations in peripheral maternal plasma over the 24-h study period after treatment between the mifepristone and placebo groups. The mean induction abortion interval in the mifepristone group was 512 (SD 321) min compared with 1128 (SD 606) min in the placebo group (P less than or equal to 0.02). The mechanism whereby mifepristone provokes enhanced uterine contractility and sensitivity to prostaglandins, with a reduction in abortion times, does not appear to be through endogenous production of PGE or PGF.

[Relations of catecholamine and prostaglandin contents in the blood of rats exposed to acute stress and during adaptation to stress]

In Wistar male rats, 1-h acute immobilization stress resulted in the increased plasma adrenalin, noradrenaline and dopamine in approximately 13, 8 and 23 times, respectively. Plasma PGF2 alpha increased in 3.5 times while PGE remained unchanged; this resulted in the decreased PGE/PGF2 alpha relation in 2.8 times. The PGI2/TXA2 relation also decreased in 1.5 times due to a more pronounced growth of TXA2 than that of PGI2. In rats adapted to the repeated stress (12 sessions), the plasma catecholamine level was higher than that in control but 2-3 fold lower than in unadapted rats after acute single stress. In this situation, PGE was increased by 70% as compared to the control. This is why PGE/PGF2 alpha relation was similar to the control whereas the level of PGF2 alpha increased. PGI2 increased by 53% and TXA2--in two times as compared to the control. In these rats, acute stress induced neither plasma catecholamine enhancement nor PGE/PGF2 alpha relation decrease in comparison with the initial levels; the TXA2 content was increased but it was by 33% less than that in unadapted rats exposed to such stress. One can suggest that the decreased activation of adrenergic system respondent to acute stress in unadapted rats is associated with the increase in plasma PGE and PGI2 which are known to limit the catecholamine release from adrenergic terminals and their harmful effects.

Procedures for plasma prostaglandins assay from bronchial asthmatic patients using 9-anthryldiazomethane-HPLC method

We report here an efficient method for simultaneous and quantitative determinations of plasma prostaglandins (PGs) from asthmatic patients using 9-anthryldiazomethane-reversed-phase high performance liquid chromatography (HPLC). Detection and simultaneous quantitation of 20 pg PGE1, PGE2, PGF2 alpha and 100 pg 6-keto PGF1 alpha, thromboxane B2 (TXB2) was possible by the present method. Preliminary studies showed that plasma TXB2 levels from stable asthmatic patients were elevated compared with normal healthy subjects, suggesting pathophysiologic implications regarding PGs and TXB2 in asthma may be elicited by the present HPLC method.

Elevation of immunoreactive platelet prostaglandin E and plasma prostaglandin F2 alpha in diabetic pregnancy

Platelet prostaglandin (PG) E and plasma PGF2 alpha concentrations were measured by radioimmunoassay methods and compared in non-pregnant and pregnant, normal and diabetic subjects. The blood samples were obtained in the follicular phase in the non-pregnant women and in the third trimester and after delivery in the pregnant women. The immunoreactive platelet PGE (IRPGE) levels were significantly higher in the pregnant diabetic women than in the normal non-pregnant and pregnant women and diabetic non-pregnant women. The immunoreactive plasma PGF2 alpha (IRPGF2 alpha) concentrations were significantly higher in the non-pregnant diabetic women than in the normal non-pregnant and pregnant women. During pregnancy, the plasma IRPGF2 alpha were further increased significantly in the diabetic subjects compared to the non-pregnant diabetics. Both the platelet IRPGE and plasma IRPGF2 alpha concentrations were higher in the pregnant diabetic subjects with retinopathy than in those without retinopathy. These findings suggest that pregnancy and diabetes influence the synthesis of PGE and PGF2 alpha in the platelets and plasma, respectively. The increased production of these prostaglandins are possible exacerbating factors of diabetic retinopathy during pregnancy.

Effect of feeding regimen on diurnal variation of breathing movements in late-gestation fetal sheep

There is a diurnal variation in the mean incidence and amplitude of fetal breathing movements (FBMs) in sheep after approximately 120 days gestation. To determine whether this variation is caused by diurnal fluctuations in plasma glucose or prostaglandin (PG) concentrations, we studied two groups of pregnant sheep fed either once daily at 1100 h or every 2 h for 24 h. Maternal and fetal blood samples were taken every 2 h from 0900 to 0900 h the next day for assay of plasma glucose and PGE2 and PGF2 alpha concentrations. FBMs were recorded throughout the 24 h. The mean fetal plasma glucose concentrations of the once-daily and multifed groups were not different, but there was a significant difference between the two groups in the 24-h pattern of fetal glucose concentrations. In the once-daily fed group, plasma glucose concentrations reached a peak 8 h after maternal feeding and then declined, whereas in the multifed group, fetal plasma glucose concentrations reached a plateau and were constant from 1300 to 0900 h the next day. Fetal plasma PGE2 and PGF2 alpha concentrations did not show a significant change with time of day in either group. There was a significant diurnal variation in the incidence and amplitude of FBMs in each of the two feeding groups, and the 24-h pattern of FBMs did not differ significantly between groups. Therefore it would appear that the diurnal variation of FBMs is not a consequence of the maternal feeding regimen or diurnal changes in plasma glucose or PG concentrations.

Effect of uterine manipulation 35 days after parturition on plasma concentrations of 13, 14-dihydro-15-keto prostaglandin F2 alpha in multiparous and primiparous Brahman cows

Thirteen multiparous (M; 451 kg, 6.1 body condition score) and 11 primiparous (P) Brahman cows (408 kg, 6.3 body condition score) were assigned randomly within parity to receive either 2-min uterine manipulation (UM) per rectum 35 d after calving or no UM (C). This resulted in four groups: MUM (n = 8), MC (n = 5), PUM (n = 5) and PC (n = 6). All animals received a jugular cannula on d 34. Blood samples were collected at 10-min intervals from 30 min prior to UM until 120 min after UM and at 20-min intervals through 300 min after UM. Plasma was harvested immediately and stored at -20 degrees C until RIA for 13, 14-dihydro-15 keto prostaglandin F2 alpha (PGFM). Number of PGFM peaks in 330 min and amplitude of these peaks were similar (P greater than .10) in MC (2.0 peaks, 445.6 pg/ml) and PC (1.8 peaks, 446.9 pg/ml). Response to UM differed (P less than .02) by parity. The PGFM response of UM and C primiparous cows did not differ. Mean PGFM concentrations between 70 and 300 min after UM were greater (P less than .05) in MUM than in MC cows. Area of the PGFM curve did not differ (P greater than .10) in primiparous groups but was greater (P less than .01) in MUM than in MC cows. Uterine manipulation 35 d after parturition increased plasma PGFM in M but not in P cows.

Arginine vasopressin stimulation of prostaglandin F2 alpha release in heifers during the estrous cycle

The effect of arginine vasopressin on the stimulation of prostaglandin F2 alpha (PGF2 alpha) release has been examined in vivo. Fifty-eight heifers received one intravenous injection of 10 IU arginine vasopressin on either Day 0 (n = 14), Day 6 (n = 12), Day 13 (n = 14) and Day 18 or 19 or 20 (Day 18-20, n = 18) after the onset of oestrus (Day 0) to determine the effect of arginine vasopressin at different times of the oestrous cycle. Frequent blood samples were taken before and after arginine vasopressin injection for the measurement of 13,14-dihydro-15-keto-PGF2 alpha (PGFM) by radioimmunoassay (RIA). Blood samples for progesterone determinations were taken 2 hr before and 24 hr after arginine vasopressin to monitor luteal function. The data show that arginine vasopressin causes an increase (P less than 0.005) in PGFM concentrations only at Day 18-20 of the cycle in 67% of the experimental heifers.

Basal prostaglandin synthesis by the isolated perfused rat kidney

In order to assess the main characteristics of the prostaglandin (PG) biosynthesis by the isolated perfused rat kidney, the urinary and venous outputs of PGE2, PGF2alpha, 6-keto-PGF1alpha and of thromboxane (Tx)B2 were followed during 120 min after an equilibration period of 30 min. Single pass kidneys were perfused with a Krebs-Henseleit solution added with Polygeline at a constant flow rate providing a perfusion pressure about 90 mm Hg. From the beginning of the study, major differences could be observed in the renal biosynthetic rate of the 4 PG studied which were mainly excreted into the venous effluent. During the perfusion, urinary and venous outputs of PGE2, PGF2alpha and of TxB2 remained stable whereas those of 6-keto-PGF1alpha sharply increased and were found inversely related to the glomerular filtration rate (r = -0.95; p n 0.001). Finally, the urinary and venous outputs of each of the four PGs studied were found positively related. It is concluded that the isolated perfused rat kidney is a valuable preparation for studying the biosynthesis of PGs and that, at least in thi model, the urinary excretion of PGs is a good index of their renal synthesis.

Physiological responses to intramammary or intravenous treatment with endotoxin in lactating dairy cows

Twenty-one, middle to late lactation Holstein cows were assigned to one of three treatments in a completely randomized design to examine physiological changes associated with intramammary or intravenous administration of Escherichia coli endotoxin. Treatments were 1) Hank's balanced salt solution infusion in two contralateral quarters (control), 2) E. coli endotoxin infusion in two contralateral quarters, and 3) intravenous infusion of E. coli endotoxin. Blood was sampled and rectal temperature was measured at 30-min intervals. Endotoxin treatment was at 0900 h and sampling continued until 1700 h. Serum prolactin, cortisol, and 13,14-dihydro-15-keto-prostaglandin F2 alpha were measured. A pyretic response was observed in intravenous and intramammary treatment groups after endotoxin treatment. Response peak was higher (41.1 vs. 40.3 degrees C) and occurred later (6 vs. 4.5 h posttreatment) in the intramammary than the intravenous treatment group. Significant prolactin peaks were observed also in intravenous and intramammary endotoxin treatment groups. Prolactin peaked higher (288 vs. 112 ng/ml) and occurred sooner (1 vs. 4 h posttreatment) in the intravenous than in the intramammary treatment group. Cortisol followed a trend similar to prolactin. Cortisol peaked higher (100 vs. 82 ng/ml) and sooner (2.5 vs. 4.5 h posttreatment) in the intravenous than in the intramammary treatment group. Concentrations of 13,14-dihydro-15-keto-prostaglandin F2 alpha increased rapidly posttreatment in the intravenous group only.

The effect of Toxoplasma gondii infection in unvaccinated and iscom-vaccinated pregnant ewes as monitored by plasma levels of 15-ketodihydroprostaglandin F2 alpha, progesterone, and oestrone sulphate

In order to study the effect of Toxoplasma infection on hormonal levels in pregnant ewes, twenty-eight Scottish Blackface ewes were dosed orally with Toxoplasma gondii oocytes at 91 +/- 1 days of gestation. Fifteen of these ewes were vaccinated with an experimental Toxoplasma iscom vaccine prior to inoculation. Further three ewes were used as non-infected controls. All challenged ewes became infected. Plasma was analysed for the content of 15-ketodihydro-PGF2 alpha, progesterone and oestrone sulphate. The endocrinological changes appeared to reflect the pathological changes in the uterus. Infected animals tended to show an increase in the levels of the prostaglandin metabolite between two and eleven days after challenge, followed by a decrease in progesterone and later also of oestrone sulphate levels. Following the initial phase, the pattern was more variable but related to the outcome of gestation. There was a marked tendency towards more normal endocrinological patterns in the vaccinated animals in comparison to unvaccinated challenged ones.

A clinical and endocrine study on the effect of orally administered bacterial endotoxin in adult pigs and goats

Endotoxin of Gram-negative bacteria was orally administered in 5 female pigs and 8 male goats. Two of the gilts were pregnant. A solution of lipopolysaccharide (LPS) of Enterobacter agglomerans was mixed into the feed ration of the pigs (40 mg/animal), and given by gastric tube into the rumen of the goats (1-20 mg/animal). Jugular venous blood was collected and clinical signs, rectal temperature and WBC counts were recorded for 12-24 hours. Plasma concentrations of the major plasma metabolite of PGF2 alpha, 15-keto-13,14-dihydro-PGF2 alpha were determined in both species, progesterone concentration only in pigs. The pigs showed slight to severe signs of endotoxemia. Increases in rectal temperature and levels of the PGF2 alpha metabolite occurred in 3 gilts. Progesterone level and the total WBC counts remained unchanged. Differential counts followed irregular patterns mostly within the normal range. The goats showed slight signs of discomfort. Temperature increased in one animal. No other parameters were altered after the intake of LPS. The observations in pigs indicate that endotoxin either penetrated the intestinal barrier causing systemic endotoxemia or induced inflammatory reactions in the intestine activating inflammatory mediators.

Initiation of parturition and lactation in the sow: effects of delaying parturition with medroxyprogesterone acetate

The synthetic progestagen, medroxyprogesterone acetate (MPA), was administered to sows in late pregnancy with the objective of slightly delaying the time of farrowing and thereby providing more marked associations between hormonal changes and the termination of pregnancy, and the initiation of farrowing and lactation in this species. MPA was administered orally (140 mg, twice daily) to eight sows in late pregnancy on days 112, 113 and 114 of gestation. Parturition was then induced to occur on day 116 by injecting 200 micrograms cloprostenol i.m. on day 115 of gestation. The peripartum changes in the plasma concentrations of progesterone, cortisol, oestradiol-17 beta, relaxin, prolactin, lactose and 13,14-dihydro-15-keto prostaglandin F2 alpha (PGFM) were measured in these sows together with a group of untreated sows. The gestational length for the MPA-treated sows (116.3 +/- 0.3 days, mean +/- S.E.M.) was significantly (P less than 0.01) greater compared with the untreated sows (114.9 +/- 0.3 days). Plasma progesterone declined earlier (P less than 0.05) with respect to the time of parturition in the treated sows compared with the untreated group. With respect to the timing of parturition, the time at which maximal concentrations of relaxin were attained and the timing of the subsequent decline were earlier in the MPA-treated sows. In both groups of sows, the concentration of relaxin increased before the decline in plasma progesterone. In the untreated sows, the concentration of PGFM increased either slightly before or at the same time as the decline in plasma progesterone, whereas in sows treated with MPA, progesterone concentrations began to decline before any significant increase in the plasma concentration of PGFM. The profiles of cortisol, oestradiol-17 beta and PGFM were similar in both groups of sows. In both groups of sows, the timing of the initial increase in the concentration of plasma prolactin coincided with a similar rise in plasma lactose (P less than 0.01). Plasma progesterone either declined earlier or at the same time as the rise in plasma lactose (P less than 0.01) in the treated group of sows only. We conclude that since the prepartum changes in the concentration of progesterone and relaxin occurred before significant changes in the concentration of PGFM in the MPA-treated sows, the nature of the luteolytic factor and the mechanism by which it exerts its action remains obscure. The higher concentration of lactose in the mammary secretion at birth in the MPA-treated sows compared with the untreated group suggested that lactogenesis was initiated earlier with respect to parturition following MPA treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Regulation of prostaglandin biosynthesis with flunixin meglumine in the bovine species

Flunixin meglumine (FM) was injected in 2 oophorectomized cows to follow changes in basal levels of the main circulating prostaglandin (PG)F2 alpha metabolite, 15-ketodihydro-PGF2 alpha. A rapid decrease in the levels was seen after FM and the effect was lasting for about 6 h. Thus, to obtain a full effect of the drug on prostaglandin synthesis it is recommended that FM should be injected 4 times daily. This concept was further studied in 3 cycling heifers which obtained FM 4 times daily from day 15 of the estrous cycle for 7 days (totally 28 injections). During the period of drug administration, prostaglandin metabolite levels were decreased and the expected pulsatile release seen during luteolysis was delayed. The pulsatile release started about one day after cessation of treatment and then luteolysis occurred. Progesterone levels were normal during the FM treatment and dropped concomitantly with the pulsatile release of PGF2 alpha. The levels of progesterone decreased to low levels before the heifers showed signs of estrus and ovulated. The administration of FM causes a situation resembling that seen during early pregnancy and FM can be a useful tool in understanding the mechanism behind maternal recognition of pregnancy.

The effect of Toxoplasma gondii infection in flunixin meglumine treated pregnant ewes as monitored by plasma levels of 15-ketodihydroprostaglandin F2 alpha, progesterone, oestrone sulphate and ultrasound scanning

The aim of this study was to examine the endocrinological response (15-ketodihydro-PGF2 alpha, progesterone and oestrone sulphate) of pregnant ewes which were constantly treated with flunixin meglumine (FM) after infection with Toxoplasma gondii. Seven Swedish Peltsheep ewes were dosed orally with 2,000 T. gondii oocysts at 90.5 (82-94) days of pregnancy. The ewes were treated with FM, 1 mg/kg, intramuscularly twice a day, starting one day before infection until the end of the gestation period. Further three ewes were treated with FM alone during the corresponding time of pregnancy. Another four ewes were used as uninfected and untreated controls. All infected ewes developed antibodies to T. gondii and aborted, but the FM treated control group and the non-treated control group, which remained seronegative, delivered the lambs in the normal gestation range. No early abortions (less than 10 days after infection) were seen in the infected group. The endocrinological changes reflected the pathological changes in the uterus and foetuses. FM could neither completely inhibit prostaglandin release during abortion nor the physiological change of the hormone before parturition even though it depressed prostaglandin release before abortion or parturition and eliminated fever. The infectious process caused by the organism was probably not affected. FM treatment alone had no observed negative effects on pregnant ewes and their foetuses.

Reproductive hormones during termination of early pregnancy with mifepristone

Thirteen women received a single oral dose of 600 mg mifepristone (RU486; Roussel-Uclaf, Paris, France) on day 0 to induce first-trimester abortion. Eleven women had a complete abortion, and 2 had a continuing pregnancy and were considered as failures. Plasma levels of human chorionic gonadotropin (hCG) increased from day 0 in all women, but dropped sharply after day 3 in women with successfully induced abortion. In these women, the levels of progesterone, 17 alpha-hydroxyprogesterone and estradiol-17 beta increased from day 0 to day 1 and then dropped. In the 2 failed inductions, the steroid levels remained virtually unchanged. In the complete abortions, the main prostaglandin F2 alpha metabolite, 15-keto-13,14-dihydro-PGF2 alpha, increased to a significant peak at day 6 followed by a significant fall to day 14. These findings supports a direct effect of mifepristone on the decidua, initiating prostaglandin synthesis. It is also suggested that there is a luteolytic effect of prostaglandin F2 alpha, as the levels of corpus luteum steroids started to fall before the drop in hCG.

Vaginal administration of PGE2 for induction of labor stimulates endogenous PGF2 alpha production

Prostaglandin E2 is effective for induction of labor but many preparations exist using a variety of vehicles from which the active ingredient may not be equally available. Plasma concentrations of bicyclic PGE2 metabolite (PGEM) and 13, 14-dihydro, 15-keto PGF2 alpha (PGFM) were measured following administration of a 3mg PGE2 vaginal tablet or 1mg PGE2 vaginal gel to twenty-four parous women with favorable induction features, randomly allocated to receive one or other preparation. PGEM increased rapidly following both administration of the 3mg PGE2 vaginal tablet and the 1mg PGE2 vaginal gel, reaching a peak within 40 minutes of PGE2 administration. The maximal rise in PGEM in the gel group correlated directly with the change in cervical score and inversely with the need for augmentation with oxytocin and the induction-delivery interval. A secondary rise in PGFM was noted in both groups 3-4 hours following PGE2 administration. The magnitude of the increase in PGE2 may be important in the clinical response to PGE2 administration, while PGE2 absorption may switch-on endogenous PGF2 alpha production, similar to what is seen in spontaneous labor.

Effects of bromocriptine at parturition in the tammar wallaby, Macropus eugenii

Female tammar wallabies were treated with the dopamine agonist bromocriptine at the end of pregnancy to suppress the peripartum pulse of plasma prolactin. The animals were subsequently observed, and a series of blood samples taken to define the hormonal profiles before and immediately after parturition. Birth was observed in 4/5 control animals and occurred in 8/9 bromocriptine-treated animals. The peripartum peak in plasma PGFM concentrations was not affected by bromocriptine although the pulse of prolactin normally seen at parturition was completely abolished. The timing of luteolysis was apparently unaffected, as plasma progesterone concentrations fell similarly in both treated and control animals immediately after parturition. However, all of the neonates of the bromocriptine-treated animals died within 24 h, possibly because of a failure to establish lactation. Subsequent onset of post-partum oestrus was delayed or absent both in control and in bromocriptine-treated animals, suggesting that the frequent blood sampling and disturbances in the peripartum period interfered with these endocrine processes. It is concluded that both prolactin and prostaglandin can induce luteolysis in the pregnant wallaby, but that the normal sequence of events results from a signal of fetal origin inducing a prostaglandin release from the uterus, which in turn releases a pulse of prolactin that induces a progesterone decline.

Effect of continuous infusion of oxytocin on prostaglandin F2 alpha secretion and luteolysis in the cyclic ewe

Circulating concentrations of 13,14-dihydro-15-keto PGF2 alpha (DHKF2 alpha), luteinizing hormone (LH) and prolactin (PRL) have been measured in cyclic ewes treated with continuous infusions of oxytocin, in order to investigate the mechanism by which the treatment delays luteal regression. Continuous infusion of oxytocin reduced prostaglandin F2 alpha (PGF2 alpha) secretion but had no detectable direct effect on LH or PRL. Oxytocin (3 nmol h-1 i.v.) given from Day 12 or 13 until Day 18 after oestrus delayed luteolysis, eight out of nine treated ewes not returning to behavioural oestrus until Day 29.1 +/- 3.2 (mean +/- s.e.m.; cycle length of control ewes 16.7 +/- 0.3 days). In the ewe in which oxytocin failed to prevent luteolysis, luteal regression had commenced before oxytocin treatment was started. In three ewes undergoing delayed luteolysis (cycle lengths, 21, 24 and 25 days) basal concentrations of PGF2 alpha (measured as DHKF2 alpha) were unchanged, but there was only one episode of PGF2 alpha secretion compared with 20 episodes in three control ewes. Prolactin secretion was pulsatile during oxytocin infusion, and levels were low following infusion in ewes with cycle length greater than 25 days while the corpora lutea were maintained. Circulating PRL concentrations were high in ewes undergoing delayed luteolysis but there was not discrete episode of PRL secretion associated with the pre-ovulatory LH surge in these animals. To investigate the possibility that the pattern of PGF2 alpha secretion was affected by depletion of oxytocin from corpora lutea, ewes previously treated with oxytocin to delay luteolysis were given a luteolytic dose of cloprostenol on Day 21 after oestrus. The amount of oxytocin secreted in response to cloprostenol was less than 10% of that seen in ewes similarly treated on Days 11-13 after oestrus. Low levels of luteal oxytocin may therefore reduce PGF2 alpha secretion in ewes undergoing delayed luteolysis.

Biological responses of sheep treated with endotoxin-contaminated superoxide dismutase and endotoxin preparations

The purpose of this study was to evaluate the biological response of sheep to different doses of endotoxin and endotoxin-contaminated enzyme preparations. The enzyme used in this experiment was superoxide dismutase (SOD), as it is currently being used in many different experiments and because several preparations were found to be heavily contaminated with endotoxin. A group of ewes were injected intravenously with a variety of different treatments. Peripheral blood was used to determine the total number of leukocytes, a differential cell count to find out the numbers of polymorphonucleocytes (PMN) and monocytes (M), and to measure the concentration of 15-ketodihydro-PGF2 alpha. In addition, rectal temperature was recorded. Treatments included saline (control), Pharmacia-Chiron's Cu/Zn-SOD (r-hSOD, 8 mg/kg), Sigma's bovine SOD (bSOD, 8 mg/kg), Grünenthal's bSOD (8 mg/kg), various doses of Salmonella typhimurium endotoxin (1000, 200, 100, 50, 20, 10, 5, and 1 ng/kg), and a mixture of endotoxin (200 ng/kg) plus r-hSOD (8 mg/kg). Results indicate that sheep react to endotoxin-contaminated SOD preparations with an endotoxemia which is similar to that seen in animals receiving endotoxin alone. This endotoxemia includes, among other things, a rise in rectal temperature, a peak in the PGF2 alpha metabolite, and an increased PMN/M ratio. Endotoxin administered at doses of 50 to 200 ng/kg also caused the expected signs of endotoxemia. At 1000 ng/kg endotoxin actually led to a decreased rectal temperature. This may be due to a type of endotoxemic shock, resulting in a decrease in peripheral blood circulation. Low doses of endotoxin (10, 5, and 1 ng/kg) caused a leukocytosis via increases in PMN; no greater changes in rectal temperature or the PGF2 alpha metabolite were noted. The combination of r-hSOD with 200 ng/kg of endotoxin caused an endotoxemia similar to that caused by 200 ng/kg of endotoxin alone. In conclusion, if an endotoxin-contaminated SOD-preparation was used to study the efficacy of SOD, there would be a serious risk of interaction by the endotoxins. In such a case it would be impossible to distinguish the effects of the endotoxin from those of the preparation itself. It is therefore important that researchers are alert to the problem of endotoxin contamination.

Control of parturient behaviour by prostaglandin F-2 alpha in the tammar wallaby (Macropus eugenii)

Nulliparous female tammar wallabies during the non-breeding season and adult male wallabies were treated with PGF-2 alpha at doses of 0.008, 0.04, 0.2 and 1.0 mg/kg. All the male and female wallabies responded to the three highest doses by showing parturient behaviour. At the lowest dose 4/4 males and 1/4 females responded. The peak concentrations of PGF-2 alpha metabolite (PGFM) in the peripheral plasma after administration of 0.008, 0.04 and 0.2 mg PGF-2 alpha/kg were 0.70 +/- 0.08, 3.02 +/- 0.37 and 8.48 +/- 0.76 ng/ml (mean +/- s.e.m.). Since the peak plasma concentrations of PGFM at normal parturition are reported to be 2.5 +/- 0.9 ng/ml, parturient behaviour can be induced by physiological concentrations of exogenous PGF-2 alpha. The effectiveness of PGF-2 alpha in males indicates that parturient behaviour is probably a result of a direct action of PGF-2 alpha on the brain, rather than a response to uterine or vaginal contractions. These experiments confirm that PGF-2 alpha is an important behavioural hormone in the tammar wallaby.

Uteroplacental production of eicosanoids in ovine pregnancy

Dramatic cardiovascular alterations occur during normal ovine pregnancy which may be associated with increased prostaglandin production, especially of uteroplacental origin. To study this, we examined (Exp 1) the relationships between cardiovascular alterations, e.g., the rise in uterine blood flow and fall in systemic vascular resistance, and arterial concentrations of prostaglandin metabolites (PGEM, PGFM and 6-keto-PGF1 alpha) in nonpregnant (n = 4) and pregnant (n = 8) ewes. To determine the potential utero-placental contribution of these eicosanoids in pregnancy, we also studied (Exp 2) the relationship between uterine blood flow and the uterine venous-arterial concentration differences of PGE2, PGF2 alpha, PGFM, 6-keto-PGF1 alpha, and TxB2 in twelve additional late pregnant ewes. Pregnancy was associated with a 37-fold increase in uterine blood flow and a proportionate (27-fold) fall in uterine vascular resistance (p less than 0.01). Arterial concentrations of PGEM were similar in nonpregnant and pregnant ewes (316 +/- 19 and 245 +/- 38 pg/ml), while levels of PGFM and PGI2 metabolite 6-keto-PGF1 alpha were elevated 23-fold (31 +/- 14 to 708 +/- 244 pg/ml) and 14-fold (12 +/- 4 to 163 +/- 78 pg/ml), respectively (p less than 0.01). Higher uterine venous versus uterine arterial concentrations were observed for PGE2 (397 +/- 36 and 293 +/- 22 pg/ml) and 6-keto-PGF1 alpha (269 +/- 32 and 204 +/- 32 pg/ml), p less than 0.05, but not PGF2 alpha or TxB2. Although PGFM concentrations appeared to be greater in uterine venous (1197 +/- 225 pg/ml) as compared to uterine arterial (738 +/- 150 pg/ml) plasma, this did not reach significance (0.05 less than p less than 0.1). In normal ovine pregnancy arterial levels of PGI2 are increased, which may in part reflect increased uteroplacental production. Moreover the gravid ovine uterus also appears to produce PGE2 and metabolize PGF2 alpha.

Prolactin and plasma prostaglandin metabolite levels in patients undergoing nipple stimulation contraction stress tests

Twenty-five patients undergoing nipple stimulation contraction stress tests were enrolled in this study. Plasma 13,14-dihydro, 15-keto prostaglandin F2 alpha and plasma prolactin concentrations were analyzed before and during the contraction stress tests. Prolactin concentrations were significantly higher (p less than 0.01) in patients who responded with a successful stress test versus those who did not. No significant changes were observed in the mean concentration of plasma 13,14-dihydro, 15-keto prostaglandin F2 alpha levels between the two groups.

Prostaglandin F2 alpha in leprosy--a preliminary study

Prostaglandin F2 alpha was estimated in the sera of fifty patients in the leprosy spectrum to find out the status of prostaglandins in response to Mycobacterium leprae. Contrary to expectation, PGF2 alpha could be detected in only twenty-eight percent of leprosy patients. This preliminary finding is discussed in detail in the paper.

Noncyclooxygenase oxidative formation of a series of novel prostaglandins: analytical ramifications for measurement of eicosanoids

Analysis of fresh plasma from normal volunteers by negative ion chemical ionization GC/MS reveals what appear to be multiple PGF2 compounds with levels ranging from approximately 5 to 40 pg/ml. Interestingly, storage of plasma at -20 degrees C for several months was found to markedly increase the levels of these compounds to about 1000-4000 pg/ml, approximately 50-fold higher than levels detected in fresh plasma. Further studies aimed at understanding this observation revealed that alkaline hydrolysis of plasma lipids also yielded quantities of these compounds in the range that were detected in stored plasma. Employing a number of approaches such as deuteriated derivatives, hydrogenation, immunoreactivity with an anti-9 alpha, 11 beta-PGF2 antibody, and electron ionization mass spectral analysis, convincing evidence was obtained that these compounds in both stored and base-treated plasma were in fact PGF2 compounds. Formation of these compounds was found to occur by a nonenzymatic oxidative process in that the antioxidant, butylated hydroxytoluene, and the reducing agent, triphenylphosphine, markedly suppressed their formation. Evidence is presented to support a proposed mechanism that oxidative formation of these compounds involves the formation of endoperoxide intermediates which are directly reduced by naturally occurring biological substances to PGF2 compounds. Formation of these compounds occurs very readily in biological fluids. This finding has important ramifications not only for analysis of enzymatically derived PGF2 compounds but also for other eicosanoids which can be formed by this same nonenzymatic process. These analytical concerns apply to both immunoassay methods and physical methods of analysis such as gas chromatography/mass spectrometry.

The effect of the anti-progestin mifepristone (RU 486) on plasma prostaglandin metabolite levels in early pregnancy and its influence on pregnancy termination

The effect of a single dose of RU 486 (600mg) on prostaglandin metabolite levels has been studied over a 48 h period in 20 women undergoing medical termination of early pregnancy. The results were compared with controls of similar gestation who were treated surgically. The mean (SD) PGEM levels at 0 and 48 h in the RU 486 group were 13.7 (2.7) and 13.2 (2.2) pg/ml respectively, which was not significantly different from the values of 11.7 (1.1) and 11.3 (0.4) pg/ml measured in the control patients. Similarly the mean (SD) PGFM values of 22.3 (14.7) and 17.0 (7.2) pg/ml at 0 and 48 h were not significantly different from the corresponding control values of 21.9 (13.8) and 23.8 (7.2) pg/ml. In 10 of the study patients, there were no significant changes in PGEM and PGFM concentrations prior to and at 4, 24 and 48 h after RU 486 administration. Although all pregnancies were successfully terminated with the combination of RU 486 and subsequently a vaginal pessary containing PGE1, no stimulation of prostaglandin production could be demonstrated.

[Clinical investigation of plasma prostaglandin levels in patients with digestive cancers]

Plasma PGE2 level of 45 patients with digestive cancers, 10 patients with digestive benign diseases and 10 healthy controls were examined. Some patients were also examined plasma levels of TXB2, 6-keto-PGF1 alpha and PGF2 alpha. Plasma PGE2 level of digestive cancer patients (53.5 +/- 69.1 pg/ml, mean +/- SD) were about 10 times higher compared to healthy controls (5.2 +/- 3.8 pg/ml, p less than 0.01). Patients with digestive benign diseases also revealed elevated level of plasma PGE2, but the change of value were smaller than those of digestive cancer patients. Furthermore, in the case of digestive cancer patients, significantly elevated levels of TXB2 (49.7 +/- 60.3 pg/ml, p less than 0.05) and 6-keto-PGF1 alpha (33.9 +/- 31.5 pg/ml, p less than 0.01), and significantly reduced levels of PGF2 alpha (246 +/- 63 pg/ml, p less than 0.01) were noted. The changes in plasma prostaglandin levels of digestive cancer patients may reflect, even though prostaglandins are present in normal human body and are inactivated rapidly, the biological characteristics of tumors and in vivo reactions of the host.

Effect of acute intravascular volume expansion on human fetal prostaglandin concentrations

Direct fetal intravascular transfusion is well tolerated by the human fetus. However, the rapid transfusion of high-hematocrit blood should increase vessel distention and the flow shear force. Each is known to stimulate the release of prostacyclin. We measured prostaglandins E2 and F2 alpha and the stable metabolite of prostacyclin, 6-keto-prostaglandin F1 alpha, by radioimmunoassay before, at the estimated midway point of, and at the completion of 40 umbilical venous transfusions performed because of immune hemolytic anemia. Umbilical venous pressures corrected for amniotic fluid pressure were measured at similar intervals during nine of the procedures. The mean (+/- SEM) length of gestation at transfusion was 29 +/- 1 week, opening hematocrit 23% +/- 1%, and total volume of 70% hematocrit red blood cells transfused 83 +/- 5 ml. 6-Keto-prostaglandin F1 alpha was the principal circulating fetal prostanoid and its concentration was unrelated to gestational age. Intravenous transfusion was associated with an 84% increase in 6-keto-prostaglandin F1 alpha (p = 0.03) and a 68% increase in prostaglandin E2 (p less than 0.05). The rise for each strongly correlated with the rise in the fetal umbilical venous pressure (6-keto-prostaglandin F1 alpha, r = 0.94, p = 0.0005; prostaglandin E2, r = 0.81, p less than 0.03). We conclude that 6-keto-prostaglandin F1 alpha is the principal circulating prostaglandin in the human fetus and that the release of venodilator prostaglandins may be one reason the human fetus can tolerate a large increase in intravascular volume without obvious sequelae.

[PGE and PGF2-alpha levels in the umbilical cord vessels. Relationship to acid-base equilibrium in the umbilical artery]

To asses the possible role of prostaglandins in the fetoplacental circulation during delivery PGE and PGF2-alfa plasma levels were measured in the umbilical vessels of term newborns. The levels of PGF2-alfa in blood from the umbilical vein are significantly higher and more variable than in the umbilical artery; 83.38 +/- 78.05 pg/ml versus 43.28 +/- 5.32 pg/ml. PGE levels are also higher in the vein 114.73 +/- 25.16 pg/ml than in the artery 83.63 +/- 9.22 pg/ml. There was a statistically significant negative correlation between the arterial pH and PGE in the umbilical vein these results support the idea that the plasmatic umbilical prostaglandins are synthetized by the placenta the variability in the values obtained in venous umbilical blood may reflect the different times of ligation of the umbilical cord. A decrease in fetal pH may be the stimulus for the prostaglandin synthesis by the placenta.

Transpulmonary prostaglandin F2 alpha metabolism in sheep: an in vivo model

We investigated transpulmonary enzymatic conversion of prostaglandin F2 alpha (PGF) to the 13,14-dihydro-15-keto metabolite (PGFM) in normal and acutely lung injured sheep. PGF was infused directly into the right ventricle. Sequential, simultaneous blood samples were drawn from the pulmonary artery (PA) and aorta (A). PGF and PGFM plasma concentrations were quantitated by double antibody radioimmunoassay (RIA). The pulmonary conversion rate of PGF in normal lung was established over a wide range of concentrations in intubated, normoxic, and hemodynamically stable sheep. Both zero and first order kinetics were present. PGF had no physiological effects on either pulmonary or systemic hemodynamics at any infusion rate studied. Acute lung injury was produced by intravenous injections of oleic acid into the PA until the resting mean pulmonary artery pressure doubled. Infusions were then repeated and fractional metabolism of PGF across the lung was assessed. PGF, at infusion rates of 2 micrograms/kg/min and 8 micrograms/kg/min, was metabolized greater than 70% respectively. Thus, there was no difference between control or experimental groups in PGF conversion. We conclude that the in vivo sheep lung has an extensive substrate-dependent capacity to metabolize PGF and this mechanism is resistant to severe acute oleic acid lung injury.

[Changes in the phospholipid and prostaglandin levels in chronic diseases of the biliary tract]

A study of 179 patients with functional and organic diseases of the bile tract revealed that changes of the blood phospholipids and their spectra in the blood is observed at more early stages of the disease, functional pathology and that an increased PGE2/PGF2 indicates a deficit of polyunsaturated fatty acids and prevalence of the processes of break-up of prostaglandins over their synthesis.

Clinical, endocrinological and spermatological studies after endotoxin injection in the boar

Three adult boars were injected intravenously with endotoxin from Salmonella typhimurium. Blood plasma was analysed for the contents of 15-ketodihydro-PGF2 alpha, LH and testosterone. Total amount of white blood cells and differential counts were determined in whole blood. Semen was examined for concentration, motility, volume and morphological appearance of the spermatozoa. The boars were slaughtered three months after the endotoxin injection and the testes were examined. The total number of white blood cells decreased and the levels of 15-ketodihydro-PGF2 alpha rose immediately after the endotoxin administration. An initial increase in LH was seen in two out of the three boars. The increase in LH was followed by a testosterone increase in one boar and a testosterone decrease in the other. The third boar showed no initial increase in LH but an increase in testosterone. Semen examination demonstrated various morphological changes of the spermatozoa in all boars. The changes started to appear at about the same time after the endotoxin injection, but differed among the individuals. The examination of the testes depicted no changes from what is seen in normal animals. The present results indicate that the boar responds to endotoxin similar to what is seen in the ram. The endocrine changes, e.g. in LH and testosterone, are similar to those seen after termination of heat stress. The seminal changes indicate a disturbance located in the epididymis as well as a short-term, mild degeneration in the seminiferous epithelium.

Extension of short cycles in postpartum beef cows by intrauterine treatment with catecholestradiol

Eight multiparous beef cows were used to examine the effects of intrauterine infusion of catecholestradiol (4-hydroxylated estradiol) on development and function of the first corpus luteum after parturition. Calves were weaned on day 1 (day 0 = parturition) to initiate formation of a corpus luteum (CL) by approximately day 10 or 11. Before CL formation, on days 5 to 9, cows received twice daily infusions of catecholestradiol (4 micrograms; n = 4) or vehicle (n = 4) into the uterine horn opposite the previous pregnancy. Plasma progesterone during the first estrous cycle was elevated longer (P less than .001) and reached a higher (P less than .001) concentration in cows treated with catecholestradiol. The decline in progesterone was associated with an increase in plasma 13,14-dihydro, 15-keto-prostaglandin F2 alpha (PGFM) in all cows infused with catecholestradiol. In contrast, a rise in PGFM at the end of the first short cycle was detected in only one of four cows treated with vehicle. Furthermore, PGFM concentrations were linearly related (R2 = .870; P less than .001) to concentrations of progesterone. Estradiol-17 beta concentrations were not different during the infusion period, but after formation of the first CL, estradiol remained elevated (P less than .01) in cows that received vehicle. Results of this experiment suggest that exposure of postpartum beef cows to catecholestradiol extended luteal function in association with enhanced PGFM release.

Effect of surgical manipulation, placental fluid, and flunixin meglumine on fetal viability and prostaglandin F2 alpha release in the gravid uterus of mares

Twenty-one pregnant mares with single or twin conceptuses between 41 and 65 days of gestational age were allotted to 5 treatment groups. A ventral median celiotomy was performed in all mares. In group-1 mares (3 mares, single conceptus), the uterus and fetus were palpated for 5 minutes. In group-2 mares (3 mares, single conceptus, flunixin meglumine), 250 ml of sterile placental fluid was injected into the nongravid uterine horn. In group-3 mares (4 mares, unicornuate twin conceptuses), group-4 mares (3 mares, unicornuate twin conceptuses, flunixin meglumine), and group-5 mares (8 mares, bicornuate twin conceptuses, flunixin meglumine), 1 conceptus was removed from the uterus via hysterotomy. All mares received progesterone prophylactically until day 100 of gestation or until the fetus died. The 3 mares in group 1 delivered clinically normal, live foals. The mean prostaglandin F2 alpha metabolite (PGFM) plasma concentration peaked at 180 +/- 5.2 pg/ml during uterine manipulation and fetal palpation, then declined to baseline by 1 hour. Free placental fluid (group 2) undermined the chorioallantois ventrally and resulted in fetal death within 3 hours after surgery. The mean PGFM plasma concentration peaked at 39 +/- 4 pg/ml following injection of placental fluid. None of the remaining fetuses in the 7 mares with unicornuate twin conceptuses (groups 3 and 4) survived. Five mares with unicornuate twin conceptuses (group 5) delivered single viable foals. In another mare in group 5, the fetus was alive 4 days after surgery, when the mare was euthanatized for a fractured femur.(ABSTRACT TRUNCATED AT 250 WORDS)

Interrelation among endogenous catecholamines, prostaglandin F2 alpha and prolactin in last trimester and during parturition

To investigate the interrelation among endogenous catecholamines, prolactin and prostaglandin F2 alpha, we measured the plasma levels of dihydroxyphenylalanine (DOPA), norepinephrine (NE), catecholamine metabolites (3,4-dihydroxyphenylacetic acid [DOPAC], 3,4-dihydroxyphenylethyleneglycol [DOPEG], cyclic 3',5'-adenosine-monophosphate (c-AMP), prostaglandin F2 alpha (PGF2 alpha) and prolactin (PRL) in 119 patients, before, during and after a normal labor and delivery, and in the early puerperium. In late pregnancy, DOPAC concentrations were significantly increased, and reached peak values before the onset of labor in the group who went into spontaneous labor. The DOPA, NE and DOPEG levels remained unchanged before labor. The plasma concentrations of NE, c-AMP and PGF2 alpha were significantly increased during labor. There was a positive correlation between plasma NE and c-AMP (r = 0.584, p less than 0.001), and between NE and PGF2 alpha (r = 0.401, p less than 0.001) during labor. In contrast, plasma PRL significantly decreased during labor and immediately after delivery. There was a statistically significant inverse relationship between PRL and NE (r = -0.392, p less than 0.001) and between PRL and PGF2 alpha (r = -0.523, p less than 0.001) during labor, but there was no statistical correlation among PRL, DOPA and DOPAC. In conclusion, these data suggest that the dopaminergic activity in the maternal circulation increases before the onset of labor, and the PRL release from the maternal pituitary gland during labor is probably not controlled primarily by dopaminergic neurons and may be suppressed by other mechanisms, such as the stress of labor and/or the influence of PGF2 alpha.

Effect of flunixin meglumine on prostaglandin F2 alpha synthesis and metabolism in the pig

The effect of flunixin meglumine on prostaglandin synthesis and metabolism was evaluated in the pig in vivo. It was found that the prostaglandin metabolite, 15-ketodihydro-PGF2 alpha, was decreased in the peripheral circulation within 20 min of injection of the drug. In therapeutic doses in the pig the drug had no effect on the metabolism of PGF2 alpha. Flunixin was compared with some other non-steroidal anti-inflammatory drugs in an in vitro test system utilizing sheep vesicular gland microsomes. It was concluded that this drug is a potent inhibitor of prostaglandin synthesis.

A biotin-streptavidin amplified enzymeimmunoassay for 13,14-dihydro-15-keto-PGF2 alpha

As an alternative for radioimmunoassays a new enzyme immunoassay (EIA) for the determination of 13,14-dihydro-15-keto PGF2 alpha (PGFM) has been developed. Biocytin was linked to PGFM by the N-hydroxysuccinimide method and the product (biocytinyl-PGFM) purified by reversed phase column chromatography. Biocytinyl-PGFM was used in the EIA as a bridge between the immobilized PGFM-antibody and streptavidin-peroxidase. The absolute sensitivity of the assay was about 160 amol (92% rel. binding) and required only 2 microliters plasma for PGFM estimation within the whole physiological range (0.08-20 pmol/ml). All variabilities were less than 14%. The described assay procedure may be of general applicability for other prostaglandins.

Plasma concentrations of 15-keto-13,14-dihydro-PGF-2 alpha, oestrone sulphate, oestradiol-17 beta and progesterone in pregnant guinea-pigs treated with polychlorinated biphenyls

Guinea-pigs treated by gavage with a total dose of 100 mg polychlorinated biphenyls (PCB: Clophen A50) during Days 17-61 of gestation had higher plasma concentrations of 15-keto-13,14-dihydroprostaglandin F-2 alpha, oestrone sulphate and oestradiol-17 beta during the later stages of gestation than did vehicle-treated guinea-pigs. No changes were observed in plasma progesterone concentrations. Our results provide no support for the hypothesis that an enzyme-induced decrease in progesterone concentrations is the main cause of the fetal death observed in PCB-treated guinea-pigs.

15-Keto-13,14-dihydroprostaglandin E2- and F2 alpha-metabolite levels in blood from men and women given prostaglandin E2 orally

Prostaglandin E2 (PGE2) was administered orally in a dose of 1 mg to healthy males (n = 20) and females (n = 10). Blood levels of 15-keto-13,14-dihydroprostaglandin F2 alpha (PGF2 alpha-M) and 15-keto-13,14-dihydroprostaglandin E2 (PGE2-M), determined as the rearrangement product 11-deoxy-15-keto-13,14-dihydro-11 beta, 16-cycloprostaglandin E2 (PGE2-cyclo-M), were measured. The levels of the two PG metabolites increased already 10 minutes after ingestion of the tablet and the mean peak value for PGE2-cyclo-M in the men was 4.64 nmol/l which was reached 50 minutes after PGE2 administration. The mean peak value in women was 4.99 nmol/l which was obtained after 30 minutes. The increase in PGE2-cyclo-M concentration was significantly faster (p less than 0.05) in women than in the men. The mean plasma concentration of PGF2 alpha in males were 0.20 nmol/l prior to treatment and rose after PGE2 ingestion to mean peak level of 0.84 nmol/l after 70 minutes. The corresponding values for the females were 0.18 nmol/l and 0.88 nmol/l 50 minutes into treatment. When the data from both sexes were amalgamated PGE2-cyclo-M peak levels were reached significantly (p = 0.004) sooner than the PGF2 alpha-M peak. The two PG metabolites returned to baseline levels in 70% of the individuals after 240 minutes. The increase in PGF2 alpha-M concentration following oral administration of PGE2 indicates that part of the PGE2 was reduced to PGF2 alpha.(ABSTRACT TRUNCATED AT 250 WORDS)