Prostaglandin Content of Amniotic Fluid During Pregnancy and Labour

Karim, Saiful; Devlin, Jean

doi:10.1111/j.1471-0528.1967.tb14866.x

Cited by 234 publications

(38 citation statements)

References 6 publications

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“…Prostaglandins El and F2a, which are present in human amniotic fluid (Karim & Devlin, 1967) did not alter the amount of progesterone produced in our experiments. Prostaglandin F2cc has been shown to increase the production of progesterone by rat ovaries incubated in vitro (Pharriss, Wyngarden & Gutknecht, 1968) and prostaglandin Et decreases progesterone production by rabbit ovaries in the presence of lh (Bedwani, unpublished results) but it is likely that these effects are exerted at stages before the conversion of pregneno¬ lone to progesterone.…”

Section: Resultsmentioning

confidence: 57%

Effect of Ovariectomy and of Various Hormones on the Synthesis of Progesterone by the Guinea-Pig Placenta in Vitro

Bedwani¹,

Marley²

1971

Reproduction

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Summary. Placental slices from intact and ovariectomized guinea-pigs, incubated in Krebs-Ringer solution containing nicotinamide and NAD, synthesized no progesterone de novo but were able to convert pregnenolone to progesterone.Placental slices from animals ovariectomized 6 days before the incubation synthesized twice as much progesterone from pregnenolone (16\g=m\g/g/3hr) as slices from intact animals (7 \g=m\g/g3hr, P<0\m=.\01). This suggests that the 3\g=b\-hydroxysteroiddehydrogenase activity of the placenta increases after ovariectomy.Cyclic AMP significantly reduced the conversion of pregnenolone to progesterone (P<0\m=.\02), whereas gonadotrophic hormones (lh, or a combination of hcg and pmsg) and prostaglandins E1 and F2\g=a\ had no effect in vitro.

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Section: Resultsmentioning

confidence: 57%

Effect of Ovariectomy and of Various Hormones on the Synthesis of Progesterone by the Guinea-Pig Placenta in Vitro

Bedwani¹,

Marley²

1971

Reproduction

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“…Also pertinent was their observation that the oxidative metabolism of PMNs obtained from women immediately after delivery, either vaginal or cesarean section, was similar to values obtained from normal adults. Serum levels of corticosteroids, fatty acids, and prostaglandins have been reported to differ in infants delivered with and without labor (25)(26)(27). It is possible that these or other chemical substances or physical factors per se might play a role in the alteration of PMN function.…”

Section: -mentioning

confidence: 99%

Impaired Surface Membrane Expression of C3bi but Not C3b Receptors on Neonatal Neutrophils

et al. 1987

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ABSTRACT. Because increased complement receptor expression is necessary for optimal function of adult neutrophils, we tested the hypothesis that the increased susceptibility of neonates to infection might be due to an impaired ability of neonatal neutrophils to increase expression of complement receptors in response to chemotactic stimuli. We used monoclonal antibodies and flow cytometry to compare surface expression of the receptors for the complement components C3b (CR1) and C3bi (CR3) on adult and neonatal cord blood neutrophils (PMNs). We also compared receptor expression on PMNs from infants delivered by cesarean section without labor versus infants delivered vaginally. Expression of both CR1 and CR3 was minimal on resting adult and neonatal PMNs maintained at 0" G. There was a modest increase in expression of both receptors when PMNs were warmed to 37" C. This increase was similar on adult and neonatal cells, both unfractionated in whole blood and after isolation with Percoll density centrifugation, with one exception. Expression of CR1 was greater on isolated PMNs from vaginally delivered infants versus adults when the cells were warmed to 37" C. This difference was not observed with cells from infants delivered by cesarean section without labor, suggesting this modest increase in receptor expression may be due to factors associated with labor. When isolated cells were stimulated with either N-formyl-methionyl-leucyl-phenylalanine or zymosan-activated serum, expression of CR1 increased to the same extent in both neonatal and adult PMNs. In contrast, maximal CR3 expression on cord PMNs stimulated with N-formyl-methionyl-leucyl-phenylalanine or zymosan-activated serum was only 75% of the adult values. This was significantly less than CR3 expression in adult PMNs across a broad range of N-formylmethionyl-leucyl-phenylalanine concentrations. Maximal stimulated expression of both receptors was the same in PMNs from infants delivered by cesarean section without labor and from infants delivered vaginally. The diminished CR3 expression on cord PMNs was not due to decreased responsiveness to N-formyl-methionyl-leucyl-phenylalanine per se since deficient CR3 expression was observed at all concentrations tested and also when zymosan-activated serum was the stimulus. Our observations of impaired expression of CR3, which is necessary for adherence and directed migration, may explain some of the impairment of these functions in neonatal neutrophils. (Pediatr Res 21: 306-311,1987)

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“…They are highly potent in causing uterine contraction in several species (see Bergstrom, Carlson & Weeks, 1968) and are released by distension of the guinea-pig uterus (Poyser, Horton, Thompson & Los, 1971). The increases in prostaglandin concentrations in human blood (Karim, 1968) and amniotic fluid (Karim & Devlin, 1967) during labour suggest that they may play a part in the expulsion of the uterine contents at parturition. Recent work by Aiken (1972) and Chester, Dukes, Slater & Walpole (1972) confirms this suggestion by showing that parturition is delayed -and prolonged in rats when prostaglandin production is prevented by prostaglandin synthetase inhibitors such as aspirin and indomethacin.…”

Section: Introductionmentioning

confidence: 99%

The contribution of prostaglandin production to contractions of the isolated uterus of the rat

Vane

Williams

1973

British J Pharmacology

190

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Summary1. Indomethacin and meclofenamate, both of which are potent inhibitors of prostaglandin synthetase, antagonized the contractor effects of oxytocin on the isolated uterus from the non-pregnant rat. Contractions induced by acetylcholine or prostaglandin F2a were not antagonized.2. Uteri from rats 17-22 days pregnant exhibited intermittent spontaneous contractions when used as isolated preparations. They also released prostaglandin-like activity (mainly similar to F2a) into the bathing fluid. Both the prostaglandin release and the uterine activity were abolished by indomethacin. Activity could be restored by addition of low concentrations of prostaglandin E2 or F2a.3. The release of prostaglandin F2a-like activity by the uteri increased dramatically on the expected day of delivery (day 22). 4. The results add force to the hypothesis that the spontaneous activity of some isolated organs is due to an intramural prostaglandin generation, and that increased uterine prostaglandin production contributes to the expulsion of the foetus.

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Prostaglandin Content of Amniotic Fluid During Pregnancy and Labour

Cited by 234 publications

References 6 publications

Effect of Ovariectomy and of Various Hormones on the Synthesis of Progesterone by the Guinea-Pig Placenta in Vitro

Effect of Ovariectomy and of Various Hormones on the Synthesis of Progesterone by the Guinea-Pig Placenta in Vitro

Impaired Surface Membrane Expression of C3bi but Not C3b Receptors on Neonatal Neutrophils

The contribution of prostaglandin production to contractions of the isolated uterus of the rat

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