Role of interleukin-1β in the regulation of porcine corpora lutea during the late luteal phase of the cycle and during pregnancy

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.

1979 ◽  
Vol 82 (3) ◽  
pp. 425-428 ◽  
Author(s):  
J. WATSON ◽  
C. E. PATEK

Prostaglandin F2α (PGF2α) secreted by the reproductive tissues of the pig in vitro was measured and it was found that the levels secreted by the corpus luteum and endometrium of early pregnant sows were significantly lower than those secreted by tissues during the late stage of the oestrous cycle. They were, however, comparable to levels secreted by tissues from the mid-stage of the oestrous cycle. Embryos also secreted significant amounts of PGF2α. Secretion of progesterone and oestradiol by the corpora lutea of both cyclic and pregnant pigs fell within accepted limits but embryos were also found to secrete significant amounts of oestradiol. The results suggest that luteal maintenance in the early pregnant pig is unlikely to be directly due to reduced synthesis of PGF2α.


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.


1981 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON

Cell suspensions were prepared from tissue samples of human corpora lutea obtained during the mid- and late-luteal phase of the menstrual cycle. Both oestradiol and progesterone production by dispersed cells were stimulated by similar concentrations of human chorionic gonadotrophin (hCG). As the degree of stimulation of production by hCG was greater for progesterone than for oestradiol (five- to tenfold compared with two- to threefold higher than basal production), the ratio of progesterone to oestradiol produced varied according to the level of trophic stimulation. A comparison of cell suspensions prepared from mid- and late-luteal phase corpora lutea, exposed to the same concentration of hCG (10 i.u./ml) in vitro, did not reveal a shift to oestradiol production in the late-luteal phase. Provision of additional testosterone during incubation raised the level of oestradiol production by dispersed luteal cells. At an optimum concentration of testosterone (1 μmol/l), oestradiol synthesis was not raised further in the presence of hCG or N6, O2-dibutyryl cyclic AMP, suggesting a lack of induction or activation of the aromatase system by gonadotrophin in short-term cultures. Basal and stimulated levels of progesterone production were not significantly impaired in the presence of testosterone.


Reproduction ◽  
2016 ◽  
Vol 151 (5) ◽  
pp. 517-526 ◽  
Author(s):  
Keisuke Kozai ◽  
Shota Tokuyama ◽  
Anna Z Szóstek ◽  
Yuko Toishi ◽  
Nobuo Tsunoda ◽  
...  

AbstractIn mares, prostaglandin F2α(PGF2α) secreted from the endometrium is a major luteolysin. Some domestic animals have an auto-amplification system in which PGF2αcan stimulate its own production. Here, we investigated whether this is also the case in mares. In anin vivostudy, mares at the mid-luteal phase (days 6–8 of estrous cycle) were injected i.m. with cloprostenol (250 µg) and blood samples were collected at fixed intervals until 72 h after treatment. Progesterone (P4) concentrations started decreasing 45 min after the injection and continued to decrease up to 24 h (P < 0.05). In turn, 13,14-dihydro-15-keto-PGF2α(PGFM) metabolite started to increase 4h after an injection and continued to increase up to 72 h (P < 0.05). PGF receptor (PTGFR) mRNA expression in the endometrium was significantly higher in the late luteal phase than in the early and regressed luteal phases (P < 0.05).In vitro, PGF2αsignificantly stimulated (P < 0.05) PGF2αproduction by endometrial tissues and endometrial epithelial and stromal cells and significantly increased (P < 0.05) the mRNA expression of prostaglandin-endoperoxide synthase-2 (PTGS2), an enzyme involved in PGF2αsynthesis in endometrial cell. These findings strongly suggest the existence of an endometrial PGF2αauto-amplification system in mares.


1972 ◽  
Vol 54 (1) ◽  
pp. 147-159 ◽  
Author(s):  
N. L. POYSER

SUMMARY The production of prostaglandins by the uterus and the resting levels of prostaglandins in the uterus on selected days of the oestrous cycle were determined in guinea-pigs. Prostaglandin F2α was detectable in the guinea-pig uterus in small amounts on days 13, 14 and 15 of the cycle. Prostaglandin E2 was present in even smaller amounts on days 14 and 15. The homogenized guinea-pig uterus had the ability to biosynthesize prostaglandins, from endogenous precursors, during incubation on every day of the cycle studied. Four to six times more prostaglandin F2α than E2 was produced on any one day with the amounts of prostaglandins formed increasing towards the end of the oestrous cycle. Indomethacin inhibited the biosynthesis of prostaglandins by the guinea-pig uterus. The implications of these findings are discussed.


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.


1976 ◽  
Vol 70 (1) ◽  
pp. 39-45 ◽  
Author(s):  
F. R. BLATCHLEY ◽  
B. T. DONOVAN

SUMMARY The response of the guinea-pig corpus luteum to the luteolytic influence of glass beads placed in the uterus, or to prostaglandin administration, was followed by assay of the progesterone content of blood samples collected daily. Following the introduction of glass beads into the uterus early in the cycle, the secretion of progesterone was curtailed. Treatment with prostaglandin F2α over days 4–6 or 6–8 of the cycle temporarily depressed progesterone release without shortening the life of the corpora lutea. When the drug was administered over days 8–10, 10–12 or 12–14 the depression in progesterone was not followed by any recovery. These observations indicate that the response of the corpora lutea to a luteolytic influence changes during the oestrous cycle.


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