PROSTAGLANDIN PRODUCTION BY INTRA-UTERINE TISSUES FROM PERIPARTURIENT SHEEP: USE OF A SUPERFUSION TECHNIQUE

1978 ◽  
Vol 76 (1) ◽  
pp. 111-121 ◽  
Author(s):  
M. D. MITCHELL ◽  
A. P. F. FLINT

SUMMARY A technique for the continuous superfusion of small tissue samples in vitro has been applied to the study of prostaglandin production by ovine intra-uterine tissues. Basal and oxytocin-stimulated production of prostaglandins was studied at 120–125 days of pregnancy and after dexamethasone-induced delivery. In general, the relative rate of prostaglandin production by tissues was: foetal cotyledon = maternal cotyledon>myometrium and in quantitative order the prostaglandins produced were prostaglandin E (PGE) > prostaglandin F (PGF) = 13,14-dihydro-15-oxo-prostaglandin F (PGFM). Considerable variation was found between the rates of prostaglandin production in individual sheep. Oxytocin had no effect on the production of prostaglandins by tissues obtained before labour but myometrium and maternal cotyledon obtained at delivery exhibited a significant increase in production of PGE and PGF (though not PGFM) in response to oxytocin. Administration of arachidonic acid increased the production of PGE and PGF by the foetal cotyledon.

1997 ◽  
Vol 273 (6) ◽  
pp. R2089-R2096 ◽  
Author(s):  
Massimo Bramucci ◽  
Antonino Miano ◽  
Anna Gobbetti ◽  
Massimo Zerani ◽  
Luana Quassinti ◽  
...  

Our aim was to study the role of angiotensin-converting enzyme (ACE) and angiotensin II (ANG II) on ovarian steroidogenesis and prostaglandin production of amphibian. Hormonal effects of ACE, ACE inhibitors, synthetic bullfrog angiotensin I (ANG I), and [Val5]ANG II were compared on frog ovaries of postreproductive and prereproductive periods. Very high ACE activity was found in ovary of water frog ( Rana esculenta) compared with other frog tissues, and this activity was inhibited by the typical ACE inhibitors, captopril and lisinopril. Frog ovary tissue in postreproductive and prereproductive periods was incubated in vitro in the presence of ACE (2.5 mU/ml), captopril (0.1 mM), lisinopril (0.1 mM), [Val5]ANG II (1 μM), and synthetic bullfrog ANG I (1 μM). Production of 17β-estradiol, progesterone, androgens, and prostaglandins E2 and F2α was determined. The data showed a modulation of 17β-estradiol, progesterone, and prostaglandin E2 production by ovary ACE; on the other hand, [Val5]ANG II modulated the production of progesterone and prostaglandin F2α, whereas androgen production was not influenced. The present in vitro studies suggest the existence of two pathways independently regulated by ACE and ANG II modulating ovarian steroidogenesis and prostaglandin production.


Blood ◽  
1984 ◽  
Vol 64 (2) ◽  
pp. 491-498 ◽  
Author(s):  
W Deimann ◽  
M Seitz ◽  
D Gemsa ◽  
HD Fahimi

Abstract he development of peroxidase (PO) reaction in the nuclear envelope (NE) and endoplasmic reticulum (ER) of monocytes differentiating in vitro and its relationship with arachidonic acid metabolism were studied. The PO, as visualized by the diaminobenzidine (DAB) technique, appeared in the NE and ER of the majority of monocytes within 24 hours of culture, with a substantial decrease thereafter. The influence of three major groups of agents--inhibitors of PO, of prostanoids, and of protein biosynthesis--upon the development of the PO reaction was examined. When aminotriazole, a PO inhibitor, was added to the culture medium, the appearance of PO was suppressed in the monocytes. The cyclooxygenase blocker, indomethacin, however, did not influence the development of PO. Also the blockers of protein synthesis, puromycin, cycloheximide, and actinomycin D, did not affect the appearance of PO. The prostanoids released from the monocytes, ie, prostaglandin E and thromboxane B2, were determined by radioimmunoassay and showed a time sequence of secretion that corresponded to the appearance of PO in the cells: a marked increase within the first 24 hours with a substantial decrease thereafter. The presence of the PO inhibitors aminotriazole and sodium azide in the culture medium produced a suppression of prostanoid release from the monocytes comparable with that of indomethacin. The data suggest that the PO in the NE and ER of differentiating monocytes in vitro (1) is associated with arachidonic acid metabolism, and (2) is not formed by de novo protein synthesis but rather by an activation process.


2007 ◽  
Vol 23 (4) ◽  
pp. E8 ◽  
Author(s):  
Christina Pfister ◽  
Rainer Ritz ◽  
Heike Pfrommer ◽  
Antje Bornemann ◽  
Marcos S. Tatagiba ◽  
...  

Object The current treatment for recurrent or malignant meningiomas with adjuvant therapies has not been satisfactory, and there is an intense interest in evaluating new molecular markers to act as therapeutic targets. Enzymes of the arachidonic acid (AA) cascade such as cyclooxygenase (COX)–2 or 5-lipoxygenase (5-LO) are upregulated in a number of epithelial tumors, but to date there are hardly any data about the expression of these markers in meningiomas. To find possible targets for chemotherapeutic intervention, the authors evaluated the expression of AA derivatives at different molecular levels in meningiomas. Methods One hundred and twenty-four meningioma surgical specimens and normal human cortical tissue samples were immunohistochemically and cytochemically stained for COX-2, COX-1, 5-LO, and prostaglandin E receptor 4 (PTGER4). In addition, Western blot and polymerase chain reaction (PCR) analyses were performed to detect the presence of eicosanoids in vivo and in vitro. Results Sixty (63%) of 95 benign meningiomas, 21 (88%) of 24 atypical meningiomas, all five malignant meningiomas, and all normal human cortex samples displayed high COX-2 immunoreactivity. All cultured specimens and IOMM-Lee cells stained positive for COX-2, COX-1, 5-LO, and PTGER4. The PCR analysis demonstrated no changes in eicosanoid expression among meningiomas of different World Health Organization grades and in normal human cortical and dura mater tissue. Conclusions Eicosanoid derivatives COX-1, COX-2, 5-LO, and PTGER4 enzymes show a high universal expression in meningiomas but are not upregulated in normal human cortex and dura tissue. This finding of the ubiquitous presence of these enzymes in meningiomas offers an excellent baseline for testing upcoming chemotherapeutic treatments.


2012 ◽  
Vol 60 (3) ◽  
pp. 395-407 ◽  
Author(s):  
Agata Zmijewska ◽  
Anita Franczak ◽  
Genowefa Kotwica

Interleukin-1β (IL-1β) may regulate ovarian physiology. In this study, the influence of IL-1β on secretory activity within the corpora lutea (CL) of cyclic and gravid pigs was determinedin vitroduring different stages of the CL lifespan, e.g. on Days 10–11, 12–13 and 15–16 of the oestrous cycle and pregnancy. IL-1β (10 ng/ml) increased prostaglandin E2(PGE2) secretion from CL of the cyclic and gravid pigs during studied days of the oestrous cycle and pregnancy. Increase (P < 0.05) of prostaglandin F2α(PGF2α) in IL-1β-treated CL was demonstrated only on Days 10–11 of the oestrous cycle. More potent stimulatory effect of IL-1β on PGE2than PGF2αsecretion resulted in the enhancement of the PGE2:PGF2αratio in cyclic and early pregnant CL. IL-1β increased (P < 0.05) progesterone (P4) secretion only in gravid CL and had no effect on oestradiol-17β (E2) release. Expression of cyclooxygenase-2 (COX-2) mRNA was stimulated (P < 0.05) in IL-1β-treated cyclic and gravid CL. Expression of prostaglandin synthase mRNAs in response to IL-1β did not increase. In conclusion, IL-1β modulates PGE2, PGF2αand P4secretion from porcine CL, depending on luteal stage and the surrounding hormonal milieu. The cytokine may act locally in porcine CL for luteotrophic support throughout the PGE2-mediated synthesis and secretion.


Author(s):  
M.K. Tripathi ◽  
S. Mondal ◽  
I.J. Reddy ◽  
A. Mor

Background: Corpus luteum plays key role in embryonic survival. Prostaglandins are the important regulator controlling the life span of corpus luteum. The present study investigated the effect of various doses of TNFα on in vitro PGF2α and PGE2 production and expression profiling of PGFS and PGES mRNA in buffalo Corpus Luteum (CL).Methods: Buffalo ovaries with mid-luteal phase CL were collected from the abattoir and CL were enucleated from surrounding tissues. Corpus luteum were finely chopped, rinsed with HBSS (Hanks Balanced Salt Solution) medium; supplemented with gentamycin and 0.1% BSA and incubated at 37°C for 1 hr in HBSS containing 0.1% collagenase. The cell suspension following filtration was washed by HBBS supplemented with gentamycin and 0.1% BSA (bovine serum albumin) and was treated with increasing doses of TNFα (0.1, 0.5 and 1.0 nM) and cultured at 38.5°C, 5% CO2 level for 24 hr. Result: There was dose dependent increase in concentrations of PGF2α and PGE2 with increasing doses of TNFα. The PGFS (prostaglandin F synthase) mRNA expression increased with increasing doses of TNFα. However, there was decrease in PGES (prostaglandin E synthase) mRNA expression at 0.1 nM and 0.5 nM TNFα but PGES mRNA expression increased at 1.0 nM TNFα as compared to control. It can be concluded that TNFα may alter PGES and PGFS mRNA expression and prostaglandin secretion in buffalo CL. 


1991 ◽  
Vol 130 (1) ◽  
pp. 21-32 ◽  
Author(s):  
A. M. Cowell ◽  
R. J. Flower ◽  
J. C. Buckingham

ABSTRACT Dispersed anterior pituitary cells were used to investigate the possible roles of phospholipid metabolites released by phospholipase A2 (PLA2) in the control of immunoreactive ACTH (ir-ACTH) secretion in vitro. PLA2 (15 600–62 500 U/1), the PLA2 activator melittin (0·5–20 mg/l) and arachidonic acid (1 mmol/l) all produced increases in ir-ACTH release from the cells, whilst platelet-activating factor (PAF), prostaglandin F2α (PGF2α), the prostacyclin analogues iloprost and BW245C, the thromboxane A2 (TXA2) analogue U46619, and the leukotrienes LTB4 and LTC4 were ineffective in this respect. PGF2α (100 nmol/l and 1 μmol/l), iloprost (1 μmol/l) and BW245C (100 nmol/l and 1 μmol/l) depressed corticotrophin-releasing factor-41-induced ir-ACTH secretion, while the PAF antagonist BN52021 (10 and 100 μmol/l) and LTC4 (100 nmol/l and 1 μmol/l) had no discernable effects. The secretory responses of the cells to hypothalamic extracts (0·2 hypothalami/ml) and arachidonic acid (1 mmol/l) were generally unaffected by the cyclooxygenase inhibitors ibuprofen (10 and 100 μmol/l) and indomethacin (10 μmol/l), the TXA2 synthetase inhibitor imidazole (10 μmol/l–1 mmol/l), the lipoxygenase inhibitor nordihydroguaiaretic acid (10 and 100 μmol/l) and the dual cyclo-oxygenase/lipoxygenase inhibitors phenidone (1–100 μmol/l) and BW755C (10 and 100 μmol/l). They were, however, inhibited by the dual cyclo-oxygenase/lipoxygenase inhibitor eicosatetraynoic acid (10 and 100 μmol/l), which also blocks epoxygenase and PLA2 activity and by the cytochrome P450 inhibitor SKF-525A (1 mmol/l). The results suggest that the stimulatory effects of PLA2 and arachidonic acid on ir-ACTH secretion are not effected by products generated by the cyclo-oxygenase or lipoxygenase pathways but may be mediated by metabolites generated by the cytochrome P450 pathway. Journal of Endocrinology (1991) 130, 21–32


2000 ◽  
Vol 164 (2) ◽  
pp. 179-186 ◽  
Author(s):  
C Boiti ◽  
M Zerani ◽  
D Zampini ◽  
A Gobbetti

By examining in vitro the effects of prostaglandin E-2 (PGE-2) and prostaglandin F-2alpha (PGF-2alpha) induced in the corpora lutea (CL) of pseudopregnant rabbits, we have demonstrated that these prostaglandins modulate luteal nitric oxide synthase (NOS) activity and progesterone production differently, depending on the age of the CL. On CL obtained on day 4 of pseudopregnancy (day-4), PGE-2 was found to depress NOS total activity to 13% of control and to significantly increase basal progesterone secretion by 61%, while PGF-2alpha had no effect. On day-9 CL, PGE-2 was ineffective, but PGF-2alpha caused a 2.5-fold increase of NOS activity and a marked decrease in progesterone production. Using specific inhibitors, we found that the regulatory actions of PGE-2 in vitro are mediated via the adenyl cyclase/protein kinase A (PKA) second messenger system, while the PGF-2alpha-induced luteolytic effects on day-9 CL depend upon activation of the phospholipase C/protein kinase C (PKC) system. The different responsiveness of day-4 and day-9 CL to PGE-2 and PGF-2alpha could depend on receptor availability for these two prostaglandins, even if other cellular mechanisms cannot be excluded. The present study supports a functional role for NOS in regulating the steroidogenic capacity of rabbit CL, and reveals a novel interaction between a stimulatory G-protein-coupled receptor and PKC/PKA-mediated signal transduction modulating NOS activity.


2006 ◽  
Vol 290 (4) ◽  
pp. F897-F904 ◽  
Author(s):  
Lori Warford-Woolgar ◽  
Claudia Yu-Chen Peng ◽  
Jamie Shuhyta ◽  
Andrew Wakefield ◽  
Deepa Sankaran ◽  
...  

Renal prostanoids are important regulators of normal renal function and maintenance of renal homeostasis. In diseased kidneys, renal cylooxygenase (COX) expression and prostanoid formation are altered. With the use of the Han:Sprague-Dawley- cy rat, the aim of this study was to determine the relative contribution of renal COX isoforms (protein, gene expression, and activity) on renal prostanoid production [thromboxane B2 (TXB2, stable metabolite of TXA2), prostaglandin E2 (PGE2), and 6-keto-prostaglandin F1α (6-keto-PGF1α, stable metabolite of PGI2)] in normal and diseased kidneys. In diseased kidneys, COX-1-immunoreactive protein and mRNA levels were higher and COX-2 levels were lower compared with normal kidneys. In contrast, COX activities were higher in diseased compared with normal kidneys for both COX-1 [0.05 ± 0.02 vs. 0.45 ± 0.11 ng prostanoids·min−1·mg protein−1 ( P < 0.001)] and COX-2 [0.64 ± 0.10 vs. 2.32 ± 0.22 ng prostanoids·min−1·mg protein−1 ( P < 0.001)]. As the relative difference in activity was greater for COX-1, the ratio of COX-1/COX-2 was higher in diseased compared with normal kidneys, although the predominant activity was still due to the COX-2 isoform in both genotypes. Endogenous and steady-state in vitro levels of prostanoids were ∼2–10 times higher in diseased compared with normal kidneys. The differences between normal and diseased kidney prostanoids were in the order of TXB2 > 6-keto-PGF1α > PGE2, as determined by higher renal prostanoid levels and COX activity ratios of TXB2/6-keto-PGF1α, TXB2/PGE2, and 6-keto-PGF1α/PGE2. This specificity in both the COX isoform type and for the prostanoids produced has implications for normal and diseased kidneys in treatments involving selective inhibition of COX isoforms.


1997 ◽  
Vol 86 (1) ◽  
pp. 82-84 ◽  
Author(s):  
Christopher A. Squier ◽  
Mary Kremer ◽  
Philip W. Wertz

1999 ◽  
Vol 18 (2) ◽  
pp. 77-81 ◽  
Author(s):  
J H Calvet ◽  
J-P Gascard ◽  
S Delamanche ◽  
C Brink

This study was performed to evaluate the morphological effects of sulfur mustard on human lung parenchyma in vitro and to measure the metabolites of arachidonic acid which are released during acute exposure to the alkylating agent. Histological analysis of the tissue following exposure to sulfur mustard for a period of 45 min at 10 mM revealed the presence of paranuclear vacuoles in the epithelium, specifically, in the ciliated cells. The release of metabolites of arachidonic acid were determined in the bath fluids by an enzymo-immunoassay. The basal release of prostaglandin E2 (PGE2:1.36±0.33 ng/g tissue) and 6- keto prostaglandin F1α (6-keto PGF1α: 8.83±1.17 ng/g tissue) were not modified during tissue exposure to sulfur mustard (45 min, 0.1 mM). In addition, the basal release of cysteinyl-leukotriene E4 (LTE4: 1.55±0.44 ng/g tissue) was also not altered by challenge of the tissues with sulfur mustard. In contrast, when the human lung parenchyma was stimulated with anti human IgE (anti-IgE) only the basal release of the metabolite of the 5-lipoxygenase pathway was significantly increased (LTE4: 6.84±1.57 ng/g tissue). These data suggest that sulfur mustard may produce morphological alterations in epithelial cells and at the time point studied (45 min exposure), this effect is not associated with a release of arachidonic acid metabolites. However, the increased release of LTE4 by anti-IgE suggests that the target cells for sulfur mustard and anti-IgE in the human lung may be different.


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