Contractile effect of PGF2α and PGE2 on isolated branches of uterine and ovarian artery in different days of estrous cycle and early pregnancy in pigs (original) (raw)
Related papers
Animal Reproduction Science, 1990
Local transfer of prostaglandin F2,~ from the uterine lumen into the venous and arterial blood and into the uterine, mesometrial and ovarian tissue on Day 18 of pregnancy in the pig. Anita. Reprod. Sci., 23: 223-235. Gilts of similar age and body mass were mated with a normal (eight gilts) or vasectomized boar (three gilts). On Day 17 of pregnancy or the oestrous cycle, silastic catheters were implanted into the carotid artery, utero-ovarian vein, uterine artery branch (5-10 cm from the uterine horn) and into the lumen of each uterine horn through the oviduct. The lumens of both uterine horns were ligated close to the cervix. Next day 3H-PGF2,~ (108 dpm) dissolved in 30 ml of saline was injected into the lumen of the experimental horn and 30 ml of saline into the control horn of conscious animals. Plasma samples were collected through two catheters from the experimental horn and from the carotid artery, and the radioactivity was measured every l0 min for 2 h. In pregnant gilts the radioactivity in the plasma samples collected simultaneously from the uterine artery branch on the experimental side was 50-69% higher than in the carotid artery (P< 0.05) while no significant difference was observed in nonpregnant gilts. The animals were sacrificed at 120 min of the experiment and the radioactivity in different segments of the uterine tissue (endometrium and myometrium) and in different samples of mesometrium and mesovarium was measured. In the experimental horn of pregnant as well as of nonpregnant gilts the radioactivity of the endometrium was much higher than in the myometrium (P< 0.001). The results were opposite in the control horn (P< 0.001). In pregnant, contrary to nonpregnant, gilts, significant differences in the radioactivity of mesometrial tissues taken from the same area 5-10 cm from the uterine horn were found, i.e.: 24.2 _ 9.5, 14.6 + 3.1 and 7.2 _+ 1.3 (× 103 dpm/g) in the wall of the vein, wall of the artery and the muscular layer of the mesometrium, respectively (P< 0,01). Labelled prostaglandin was found in the uterine flushing of the control horn (142.3 + 17.2 × 103 dpm and l 12,9 + 40.1 × 103 dpm for pregnant and nonpregnant gilts respectively). This concentration exceeded many fold the concentration in the blood supplying the uterine horn. It is suggested that the s. STEFAlqCZYK-KRZYMOWSKA ET AL. back transfer of PGF2. from the venous blood into the uterus with the arterial blood, and the ability of the uterine vein and artery wall to bind and retain PGF2. may be a part of the complex corpus luteum protecting mechanism during early pregnancy.
Reproduction in Domestic Animals, 2011
The origin and physiological significance of high pulses of prostaglandin F2a (PGF2a) in uterine venous blood that occur 2-3 days after luteolysis are not well understood. We studied the relationship between contractions of the uterus evoked by exogenous oxytocin (OT) and PGF2a concentration in uterine venous blood on day 17 of the porcine oestrous cycle. The infusion of OT into the uterine artery produced an immediate increase in the uterine intraluminal pressure (UIP) (p < 0.001) and a simultaneous elevation in PGF2a concentration in uterine venous blood (p < 0.0001). The infusion of indomethacin (IND) into the uterine artery slightly decreased PGF2a concentration in uterine venous blood, but it did not suppress uterine contraction or the rapid increase in PGF2a concentration in uterine venous blood just after OT infusion (p < 0.0001), which was lower that in gilts not treated with IND. We conclude that the spikes of PGF2a concentration in uterine venous blood occurring after OT infusion on day 17 of the porcine oestrous cycle are mainly caused by the excretion with venous blood from the remodelled uterus and that PGF2a synthesis may contribute to this. These results suggest that the high spikes in PGF2a concentration that occur 2-3 days after luteolysis in pigs, sheep, cows and mares all have a similar origin.
Endocrinology, 2009
Before implantation, the porcine endometrium and trophoblast synthesize elevated amounts of luteoprotective prostaglandin estradiol-17 (E 2 ) (PGE 2 ). We hypothesized that embryo signal, E 2 , and PGE 2 modulate expression of key enzymes in PG synthesis: PG-endoperoxide synthase-2 (PTGS2), microsomal PGE synthase (mPGES-1), PGF synthase (PGFS), and PG 9-ketoreductase (CBR1) as well as PGE 2 receptor (PTGER2 and -4) expression and signaling within the endometrium. We determined the site of action of PGE 2 in endometrium during the estrous cycle and pregnancy. Endometrial tissue explants obtained from gilts (n ϭ 6) on d 11-12 of the estrous cycle were treated with vehicle (control), PGE 2 (100 nM), E 2 (1-100 nM), or phorbol 12-myristate 13-acetate (100 nM, positive control). E 2 increased PGE 2 secretion through elevating expression of mPGES-1 mRNA and PTGS2 and mPGES-1 protein in endometrial explants. By contrast, E 2 decreased PGFS and CBR1 protein expression. E 2 also stimulated PTGER2 but not PTGER4 protein content. PGE 2 enhanced mPGES-1 and PTGER2 mRNA as well as PTGS2, mPGES-1, and PTGER2 protein expression. PGE 2 had no effect on PGFS, CBR1, and PTGER4 expression and PGF 2␣ release. Treatment of endometrial tissue with PGE 2 increased cAMP production. Cotreatment with PTGER2 antagonist (AH6809) but not PTGER4 antagonist (GW 627368X) inhibited significantly PGE 2 -mediated cAMP production. PTGER2 protein was localized in luminal and glandular epithelium and blood vessels of endometrium and was significantly up-regulated on d 11-12 of pregnancy. Our results suggest that E 2 prevents luteolysis through enzymatic modification of PG synthesis and that E 2 , PGE 2 , and endometrial PTGER2 are involved in a PGE 2 positive feedback loop in porcine endometrium.
Inhibition by PGI-2 of myometrial activity in vivo in non-pregnant ovariectomized sheep
Reproduction, 1982
The effects of PGI-salt and PGI-2 methyl ester on intrauterine pressure (IUP) and uterine electromyographic activity (EMG) were examined in vivo in non-pregnant ovariectomized sheep. PGI-2 salt and PGI-2 methyl ester (50\p=n-\200\ g=m\ g) reduced significantly the frequency and amplitude of IUP cycles and also inhibited the associated uterine EMG activity. Injections of oxytocin (50 mU) or PGF-2\g=a\ (2 \g=m\g)partly overcame the inhibition of IUP induced by the PGI-2 methyl ester. These results suggest that endogenous PGI-2 may be involved in the regulation of uterine activity in sheep. Materials and Methods At laparotomy under general anaesthesia 4 non-pregnant sheep were bilaterally ovariectomized. Recording balloons were placed in the uterine lumen (Lye & Porter, 1978), and 3 pairs of stainless steel electrodes (Cooner Corp., California, U.S.A.) were sutured into the myometrium at the tubai, middle and cervical regions of one uterine horn. A femoral artery and femoral vein were catheterized using vinyl tubing (Bolab, Arizona, U.
Reproduction, 1978
Prostaglandin F-2\g=a\(1\m=.\5 mg over 10 h) was infused into the anterior uterine vein of pigs on Days 6, 8, 10, 12, 14 and 15 of the oestrous cycle. At each stage of the cycle PGF-2\g=a\ suppressed luteal function although the fall in progesterone secretion was much greater and statistically significant when the infusion was performed on Days 12,14 and 15 of the cycle than on Days 6, 8 and 10. The concentration of cAMP was depressed on Days 15 and 17 and fatty degeneration of luteal cells on Days 6\p=n-\8 or 14 was more pronounced in the ovary ipsilateral to the PGF-2\g=a\infusion than in the contralateral ovary. The results are compatible with the local perfusion of PGF-2\g=a\ from the anterior uterine vein to the ipsilateral ovary, but a systemic effect was also apparent.
Reproduction, 1982
Peripheral plasma progesterone concentrations in intact and hysterectomized pseudopregnant rabbits decreased from Day 14. The rate of decrease in intact, but not in hysterectomized, rabbits accelerated on Day 17 and was associated with an increase in PGF-2\g=a\levels in the uterine venous plasma. There was no change in uterine PGE-2 output during pseudopregnancy. In pregnant rabbits, peripheral plasma progesterone concentrations remained high up to Day 30, and there was no increase in uterine venous plasma levels of PGF-2\g=a\on Day 17. PGF-2\g=a\levels were elevated in uterine venous plasma on Day 25 of pregnancy, but there was no concurrent decline in plasma progesterone concentrations. Uterine venous plasma levels of PGE-2 increased markedly after Day 11 of pregnancy and reached very high concentrations in some rabbits.
Efficacy of PGF2α on pre-ovulatory follicle and corpus luteum blood flow
2012
The aim of this study was to evaluate the effect of cloprostenol administration on the blood flow of pre-ovulatory follicle (PF) and corpus luteum (CL), progesterone secretion and pregnancy outcome in buffaloes subjected to AI. The trial was performed on 75 Italian buffaloes at 182 ± 8 days in milk. Synchronized animals were randomly divided into two groups on the day of oestrus: Group T (n = 37) received a 0.524 mg intramuscular injection of cloprostenol and Group C (n = 38) received saline. Ultrasound examinations of the ovaries were performed 5 h after AI on the PF and 10 and 20 days after AI on the CL. Resistive (RI) and pulsatily index (PI) were calculated by colour-Doppler mode in each examination. Blood samples were collected on days 10, 20 and 25 after AI for progesterone assay and 25 days after AI, ultrasonography was performed to assess pregnancy, which was confirmed on day 45. Subjects pregnant on day 25 but not on day 45 were considered to have undergone late embryonic mortality (LEM). Statistical analysis was performed by ANOVA. No differences were found in PF dimensions, CL size and blood flow on day 10 and 20 after AI between treated and control groups. Pre-ovulatory follicle area was higher in buffaloes that resulted pregnant on day 25 after AI compared to those that were non-pregnant (2.13 vs 1.66 cm in pregnant and nonpregnant buffaloes, respectively), while non-pregnant buffaloes showed higher values of RI (0.49 vs 0.30; p < 0.05) and PI (1.0 vs 0.37; p = 0.07) compared to pregnant subjects. Treatment by cloprostenol did not influence pregnancy rate both on day 25 (31 ⁄ 75; 41.3%) and 45 (27 ⁄ 75; 36.0%), progesterone levels and incidence of LEM (4 ⁄ 31; 12.9%). In conclusion, cloprostenol administration at the time of AI does not seem to affect PF and CL blood flow.
The Veterinary Journal, 2014
Although prostaglandin (PG) F 2a analogues are routinely used for oestrus synchronisation in cattle, their effects on the function of the bovine corpus luteum (CL), and on ovarian arterial contractility, may not reflect the physiological effects of endogenous PGF 2a . In the first of two related experiments, the effects of different analogues of PGF 2a (aPGF 2a ) on the secretory function and apoptosis of cultured bovine cells of the CL were assessed. Enzymatically-isolated bovine luteal cells (from between days 8 and 12 of the oestrous cycle), were stimulated for 24 h with naturally-occurring PGF 2a or aPGF 2a (dinoprost, cloprostenol or luprostiol). Secretion of progesterone (P4) was determined and cellular [Ca 2+ ] i mobilisation, as well as cell viability and apoptosis were measured.
Immunohistochemical localization of PGF2α receptor in the rat oviduct
Prostaglandins, Leukotrienes and Essential Fatty Acids, 1993
As a step towards understanding the role of prostaglandin F,, (PGF,,) in ovarian function, a rabbit antiserum against purified PGF,, receptor (PGF,,-R) was produced. This report details the use of this antiserum in immunohistocbemical staining of ovaries of non-pregnant and pregnant rats to ascertain which cell types, in vivo, possess PGF,,-R. In non-pregnant rats, three ovarian cell subpopulations contain immunoreactive PGF2,-R. These include: a subpopulation of the cells found in corpora lutea, a subpopulation of the thecal cells surrounding secondary and mature (Graafian) follicles, and a subpopulation of primary and secondary interstitial cells. The ovarian tissues and cell types in which immunoreactive PGF,,-R cannot be demonstrated include: the serosa bverlying the ovary and its vessels, the coelomic epithelium and its underlying cortical stroma, medullary stroma and vessels, granulosa cells of primary, secondary and mature follicles, the oocyte, and the blood vessels and stroma within corpora lutea. PGF2,-R immunohistochemical staining of corpora lutea from non-pregnant animals was examined both prior to the start of luteolysis and during luteolysis. During luteolysis, cells undergoing apoptosis stained for the presence of PGF2,-R. PGF2,-R immunohistochemical staining was also examined in corpora lutea during pregnancy and until 4 days postpartum. The major findings here were the apparent large increase in staining intensity of granulosa-lutein cells during pregnancy, and the loss of PGF,,-R immunopositivity of the granulosa-lutein cells during the postpartum period. In summary, three ovarian cell subpopulations, all of which can secrete steroids, possess immunoreactlve PGF2,-R.
Journal of Endocrinology, 2006
Previous studies in this laboratory have suggested that the isolated uterus from non-pregnant mice has a prostaglandin F and a thromboxane receptor population similar to that found in human myometrium. The aim of this study was to investigate any regional variation in myogenic activity and responsiveness to prostaglandin F 2 (PGF 2 ) and the thromboxane mimetic U46619 in the mouse uterus taken during different stages of the oestrous cycle and during pregnancy. Uterine samples from BKW mice were taken from different anatomical segments along the length of each uterine horn and set up for superfusion at 2 ml/min with Krebs solution (containing 1 µM indometacin) at 37 C, and gassed with 95%O 2 /5%CO 2 . Responses (area under the curve) are expressed as a percentage of the final contraction induced by hypotonic shock. Data are expressed as the means S.E.M.of n=5-12 and were analysed using Student's paired t-test or two-way ANOVA with a Bonferroni post hoc test. Regional variation in myogenic activity was observed in all tissues studied except those taken during labour. These tissues displayed significantly greater myogenic activity than tissues taken at late gestation and at all stages of the oestrous cycle. Tissues from pregnant animals were generally more responsive to U46619 and PGF 2 than tissues taken from non-pregnant animals. Tissues taken from the upper segment of the uterine horn were more responsive to both agonists during the oestrous cycle. The findings demonstrated that the hormonal milieu and site of excision are important for myogenic activity and responsiveness.