85 EFFECT OF FOLLICULAR ASPIRATION JUST PRIOR TO OVULATION ON CORPUS LUTEUM CHARACTERISTICS, CIRCULATING PROGESTERONE CONCENTRATIONS AND UTERINE RECEPTIVITY IN SINGLE-OVULATING BEEF HEIFERS

2012 ◽  
Vol 24 (1) ◽  
pp. 155 ◽  
Author(s):  
L. O'Hara ◽  
S. Scully ◽  
V. Maillo-Sevilla ◽  
A. K. Kelly ◽  
P. Duffy ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Embryo Development ◽  
Prostaglandin F2α ◽  
Uterine Receptivity ◽  
Beef Heifers ◽  
Embryo Survival ◽  
Follicular Aspiration ◽  
Follicle Aspiration ◽  
And Function

Progesterone (P4) has a crucial impact on the transcriptome of the uterine endometrium and the preparation of the uterus to support implantation. The aim of this study was to investigate the effect of follicle aspiration just before ovulation on corpus luteum (CL) development, circulating P4 concentrations and the ability of the uterus to support embryo development and conceptus elongation. We tested the hypothesis that the unavoidable loss of follicular fluid and some granulosa cells during aspiration of the preovulatory follicle would compromise the development and function of the developing CL and that this would be associated with reduced P4 and a poorer uterine environment. Oestrous cycles of crossbred beef heifers were synchronized using an 8-day CIDR treatment with administration of a prostaglandin F2α analogue on the day before CIDR removal to ensure CL regression. Heifers were checked for signs of oestrus 4 times per day commencing 30 h after CIDR withdrawal and only those recorded in standing oestrus (Day 0, n = 20) were used. All heifers received a gonadotropin-releasing hormone agonist (0.01 mg buserelin) 48 h after CIDR removal to induce an LH surge. Half of the animals underwent follicle aspiration 20 h later, while the remainder underwent ovulation. Daily transrectal ultrasonography was carried out from Day 3 to 13 to record CL development. Daily blood samples were collected from Day 0 to 14 for circulating P4 concentrations. To test the ability of the uterus to support embryo development and conceptus elongation, Day 7 in vitro-produced blastocysts were transferred to the uteri of synchronised recipients (7 to 10 blastocysts per recipient). All recipients were slaughtered on Day 14 to assess embryo survival and conceptus size. CL diameter and CL area were significantly reduced in the follicle aspirated group compared with controls from Day 6 onwards (P ≤ 0.05). Similarly, at slaughter on Day 14, CL weight (4.17 ± 0.48 vs 7.05 ± 1.65 mm), diameter (19.89 ± 1.35 vs 24.64 ± 2.07 mm) and area (321.94 ± 45.01 vs 510.18 ± 69.41 mm2) were lower in aspirated heifers (P ≤ 0.05). Circulating P4 concentrations were lower at all time points from Day 3 to Day 14 but were only significantly lower from Day 12 onwards (P ≤ 0.05). Conceptus length (2.08 ± 0.29, n = 56 vs 4.55 ± 0.78 mm, n = 45) and area (2.52 ± 0.39 vs 5.61 ± 1.12 mm2) were lower (P ≤ 0.05) in heifers undergoing follicular aspiration compared with those undergoing ovulation. In conclusion, aspiration of the preovulatory dominant follicle just before expected ovulation was associated with a compromised CL in terms of size and P4 output and this, in turn, was associated with a reduced capacity of the uterus to support the initiation of conceptus elongation. Supported by Science Foundation Ireland (07/SRC/B1156).

scholarly journals Effect of follicular aspiration just before ovulation on corpus luteum characteristics, circulating progesterone concentrations and uterine receptivity in single-ovulating and superstimulated heifers

Reproduction ◽  
2012 ◽  
Vol 143 (5) ◽  
pp. 673-682 ◽  
Author(s):  
L O'Hara ◽  
S Scully ◽  
V Maillo ◽  
A K Kelly ◽  
P Duffy ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Uterine Receptivity ◽  
Subsequent Formation ◽  
Expected Time ◽  
Follicular Aspiration ◽  
Conceptus Development ◽  
Luteal Tissue ◽  
Follicle Aspiration ◽  
Length And Area

The aim of this study was to investigate, in unstimulated and superstimulated heifers, the effect of follicle aspiration just before ovulation on corpus luteum (CL) development, circulating progesterone (P4) concentrations and the ability of the uterus to support embryo development. Following follicle aspiration or ovulation timed from GNRH administration, CL development was assessed by daily ultrasonography, and CL function was assessed in terms of the capacity to produce P4 and the expression of genes involved in steroidogenesis in luteal tissue. The capacity of the uterine environment to support conceptus development was assessed following transfer and recovery of in vitro-produced embryos. Follicular aspiration just before the expected time of ovulation leads to a significant reduction in CL diameter, CL area and area of luteal tissue. This was associated with a decrease in circulating P4 in both unstimulated and superstimulated heifers. Follicle aspiration leads to a reduction in conceptus length and area on day 14 in unstimulated heifers only. Follicle aspiration leads to a reduction in the expression of LHCGR in luteal tissue from unstimulated heifers compared with those in which the CL formed after ovulation. Superstimulation significantly reduced the expression of STAR in luteal tissue in both ovulated and follicle-aspirated heifers. In conclusion, in stimulated and unstimulated heifers, aspiration of the preovulatory dominant follicle(s) just before expected ovulation interferes with the subsequent formation and function of the CL, in terms of size and P4 output and this, in turn, is associated with a reduced capacity of the uterus to support conceptus elongation in unstimulated heifers.

Recent developments and potentialities for reducing embryo mortality in ruminants: the role of IFN-t and other cytokines in early pregnancy

1997 ◽  
Vol 9 (3) ◽  
pp. 355 ◽  
Author(s):  
J. Martal ◽  
Nicole ChÊne ◽  
Sylvaine Camous ◽  
L. Huynh ◽  
F. Lantier ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Prostaglandin F2α ◽  
Fetal Mortality ◽  
Uterine Receptivity ◽  
Embryo Survival ◽  
Embryo Mortality ◽  
Ifn Γ

This review considers the potential reduction of embryo mortality in vitro and in vivo in ruminants. Data on cytokines provided by different fields of reproductive immunology and biology were collated. Because of the crucial importance of the local interactions between the embryo and its dam, the expression of growth-factor and cytokine genes was analysed in the embryo proper, trophoblast, oviduct and endometrium by reverse transcriptase polymerase chain reaction in sheep and in cattle during the pre- and periimplantation periods. Many deleterious cytokines, such as tumour necrosis factor-α, intereron-γ (IFN-γ ), interleukin-2 (IL-2), and beneficial cytokines, such as transforming growth factor-β, leukaemia inhibiting factor, colony-stimulating factor-1 (CSF-1), ganulocyte–macrophage CSF, IL-1, IL-3, IL-4, IL-6, IL-10 and IFN-γ appeared to be involved in embryo survival in ruminants and other species. Their administration is efficient in a murine experimental model (CBA/J DBA/2) of embryonic and fetal mortality. For instance, recombinant ovine IFN-τ (roIFN-τ ) injected at the moment of implantation drastically reduces embryonic mortality in this model. In ruminants, roIFN-τ and recombinant bovine IFN-τ are very efficient in maintaining progesterone luteal secretion in cyclic animals. The involvement of IFN-τ in the mechanisms of maternal pregnancy recognition are particularly detailed in relation to inbition of 13,14 dihydro-15-keto-prostaglandin F2α (PGFM) pulses and oxytocin uterine receptivity. A synthetic model of the anti-luteolytic effects of IFN-τ on the endometrial cell is proposed. Finally, the particular potential of serum pregnancy-specific proteins (PSPs: PSPB, PSP60, pregnancy-associated glycoprotein) for monitoring embryo survival, with examples given for cattle and sheep is underlined.

Roles of interferon-stimulated gene 15 protein in bovine embryo development

2017 ◽  
Vol 29 (6) ◽  
pp. 1209 ◽  
Author(s):  
Shuan Zhao ◽  
Yi Wu ◽  
Hui Gao ◽  
Alexander Evans ◽  
Shen-Ming Zeng
Keyword(s):  
Protein Expression ◽  
Embryo Development ◽  
Cell Number ◽  
Type I ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Uterine Receptivity ◽  
Isg15 Expression ◽  
And Function

Interferon (IFN)-stimulated gene 15 (ISG15) is one of several proteins induced by conceptus-derived Type I or II IFNs in the uterus, and is implicated as an important factor in determining uterine receptivity to embryos in ruminants. But little is known about the role the ISG15 gene or gene product plays during embryo development. In the present study, both the expression profile and function of ISG15 were investigated in early bovine embryos in vitro. ISG15 mRNA was detectable in Day 0, 2, 6 and 8 bovine embryos, but IFN-τ (IFNT) mRNA only appeared from Day 6. This means that embryonic expression of ISG15 on Days 0 and 2 was not induced by embryonic IFNT. However, ISG15 mRNA expression paralleled the expression of IFNT mRNA in Day 6 and 8 embryos. ISG15–lentivirus interference plasmid (ISG15i) was injected into 2-cell embryos to knockdown ISG15 expression. This resulted in decreases in the proportion of hatching blastocysts, the diameter of blastocysts and cell number per diameter of blastocysts compared with control embryos. In addition, ISG15i inhibited IFNT, Ets2 (E26 oncogene homolog 2) mRNA and connexion 43 protein expression in Day 8 blastocysts, whereas exogenous IFNT treatment (100 ng mL–1, from Day 4 to Day 8) improved ISG15 mRNA and connexion 43 protein expression. In conclusion, it appears that ISG15 is involved in early bovine embryo development and that it regulates IFNT expression in the blastocyst.

scholarly journals Prostaglandin F2α Represses IGF-I-Stimulated IRS1/Phosphatidylinositol-3-Kinase/AKT Signaling in the Corpus Luteum: Role of ERK and P70 Ribosomal S6 Kinase

2010 ◽  
Vol 24 (3) ◽  
pp. 632-643 ◽  
Author(s):  
Edward Arvisais ◽  
Xiaoying Hou ◽  
Todd A. Wyatt ◽  
Koumei Shirasuna ◽  
Heinrich Bollwein ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Prostaglandin F2α ◽  
Serine Phosphorylation ◽  
Phosphatidylinositol 3 Kinase ◽  
Akt Activation ◽  
Diminished Capacity ◽  
Igf I ◽  
In Vitro Treatment

Abstract Little is known about the early intracellular events that contribute to corpus luteum regression. Experiments were designed to determine the effects of prostaglandin F2α (PGF2α) on phosphatidylinositol-3-kinase (PI3K)/Akt signaling in the corpus luteum in vivo and in vitro. Treatment of midluteal-phase cows with a luteolytic dose of PGF2α resulted in a rapid increase in ERK and mammalian target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase (p70S6K1) signaling and a rapid suppression of Akt phosphorylation in luteal tissue. In vitro treatment of primary cultures of luteal cells with PGF2α also resulted in an increase in ERK and mTOR/p70S6K1 signaling and a diminished capacity of IGF-I to stimulate PI3K, Akt, and protein kinase C ζ activation. Accounting for the reductions in PI3K and Akt activation observed in response to PGF2α treatment, we found that PGF2α promoted the phosphorylation of serine residues (307, 612, 636) in the insulin receptor substrate 1 (IRS1) peptide sequence in vivo and in vitro. Serine phosphorylation of IRS1 was associated with reduced formation of IGF-I-stimulated IRS1/PI3Kp85 complexes. Furthermore, treatment with inhibitors of the MAPK kinase 1/ERK or mTOR/p70S6K1 signaling pathways prevented PGF2α-induced serine phosphorylation of IRS1 and abrogated the inhibitory actions of PGF2α on Akt activation. Taken together, these experiments provide compelling evidence that PGF2α treatment stimulates IRS1 serine phosphorylation, which may contribute to a diminished capacity to respond to IGF-I. It seems likely that the rapid changes in phosphorylation events are among the early events that mediate PGF2α-induced corpus luteum regression.

scholarly journals Possible role of interferon tau on the bovine corpus luteum and neutrophils during the early pregnancy

Reproduction ◽  
2015 ◽  
Vol 150 (3) ◽  
pp. 217-225 ◽  
Author(s):  
Koumei Shirasuna ◽  
Haruka Matsumoto ◽  
Shuichi Matsuyama ◽  
Koji Kimura ◽  
Heinrich Bollwein ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Neutrophil Migration ◽  
Peripheral Circulation ◽  
Interferon Tau ◽  
Bovine Corpus Luteum ◽  
Activated Neutrophils ◽  
Endocrine Factor ◽  
Uterine Environment ◽  
And Function

When pregnancy is established, interferon tau (IFNT), a well-known pregnancy recognition signal in ruminants, is secreted by embryonic trophoblast cells and acts within the uterus to prepare for pregnancy. IFNT acts as an endocrine factor on the corpus luteum (CL) to induce refractory ability against the luteolytic action of PGF2α. Hypothesising that IFNT may influence not only the uterine environment but also the CL in cows via local or peripheral circulation, we investigated qualitative changes in the CL of pregnant cows during the maternal recognition period (day 16) and the CL of non-pregnant cows. The CL of pregnant animals had a higher number of neutrophils, and the expression of interleukin 8 (IL8) mRNA and its protein was higher as well as compared with the CL of non-pregnant animals. Although IFNT did not affect progesterone (P4) secretion and neutrophil migration directly, it stimulated IL8 mRNA expression on luteal cells (LCs), influencing the neutrophils, resulting in the increased migration of IFNT-activated neutrophils. Moreover, both IFNT-activated neutrophils and IL8 increased P4 secretion from LCs in vitro. Our novel finding was the increase in neutrophils and IL8 within the CL of pregnant cows, suggesting the involvement of IFNT function within the CL toward establishment of pregnancy in cows. The present results suggest that IFNT upregulates neutrophil numbers and function via IL8 on LCs in the CL of early pregnant cows and that both neutrophils and IL8, stimulated by IFNT, are associated with an increase in P4 concentrations during the maternal recognition period in cows.

108 FACTORS AFFECTING PREGNANCY RATES IN RECIPIENTS RECEIVING IN VITRO-PRODUCED EMBRYOS BY FIXED TIME EMBRYO TRANSFER

2016 ◽  
Vol 28 (2) ◽  
pp. 184
Author(s):  
M. Pelizzari ◽  
A. Tribulo ◽  
J. Garzon ◽  
B. Bernal ◽  
R. Tribulo ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Embryo Transfer ◽  
Body Condition Score ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Uterine Horn ◽  
Device Removal ◽  
Embryo Transfer Technique

A retrospective analysis of factors that affect pregnancy rates from 4214 fresh in vitro-produced (IVP) embryos that were transferred at a fixed-time (FTET) in 20 different farms. Recipients were all cycling cows or heifers that were synchronized with 1 of 3 treatments: 1) treatments with progesterone (P4) devices and 2 mg of oestradiol benzoate (EB) on Day 0 (day of insertion) and 24 h after device removal (Day 8); 2) treatments with P4 devices and EB on Day 0, but with 0.5 mg of oestradiol cypionate (ECP) at device removal (Day 8); or 3) treatments with P4 devices and GnRH on Day 0 and a second GnRH 60 h after device removal (Day 5). Cows in all treatment groups also received 500 µg of cloprostenol (prostaglandin F2α) at the time of P4 device removal and 400 IU of eCG either at device removal or 3 days before device removal. All embryos were transferred 7 or 8 days after the expected time of oestrus (24 h after EB, 48 h after ECP or at the time of the second GNRH for each synchronization treatment, respectively). On the day of embryo transfer, recipients were examined by ultrasonography and those with corpus luteum >14 mm in diameter received a fresh, IVP embryo in the uterine horn ipsilateral to the corpus luteum. Pregnancy rates were determined by ultrasonography 35 days after FTET. Data were analysed by logistic regression. Independent variables were classified into the following three categories. 1) Factors related to the recipient and the environment; there were no significant differences in pregnancy rates for corpus luteum diameter (≥14 and <16 mm, ≥16 and <18 mm, or ≥18 mm; P = 0.46), number of corpus luteum (1 or ≥2; P = 0.26), and category of recipient (cow or heifer; P = 0.21). However, there were significant effects of farm (P = 0.01) and body condition score (BCS; P = 0.01). Cows with BCS ≥4.5 (1 to 5 scale) resulted in lower pregnancy rates (4/20, 20.0%) than those with BCS 2 (74/225, 32.9%), 2.5 (502/1434, 35.0%), 3 (570/1467, 38.9%), 3.5 (193/532, 36.3%), and 4 (44/118, 37.3%). 2) Factors related to the synchronization treatment; there were no significant differences between recipients receiving eCG at device removal (84/209, 40.2%) or 3 days before device removal (874/2291, 38.1%; P = 0.35). However, recipients synchronized with P4 devices and ECP had higher (P = 0.01) pregnancy rates (232/483, 48.0%) than those treated with EB (679/1888, 36.0%) or gonadotropin-releasing hormone (47/129, 36.4%). 3) Factors related to the embryo transfer technique; day of the recipient’s oestrous cycle (P = 0.36), stage of embryo transferred (IETS stages 6 or 7; P = 0.62), and operator (P = 0.57) did not affect pregnancy rates. However transfers made in the anterior third of the uterine horn resulted in higher (649/1545, 42.0%) pregnancy rates than those in the mid-third (845/2511, 33.6%) or in the distal third (6/35, 17.1%; P = 0.01). It was concluded that factors related to the recipient and the environment (farm and BCS), the synchronization treatment (ECP), and the embryo transfer technique (site of deposition) affect pregnancy rates in recipients of embryos produced in vitro and transferred at a fixed time.

161 EFFECT OF OVIDUCTAL FLUID ON BOVINE OOCYTE ZONA PELLUCIDA HARDENING AND SPERM BINDING, AND ON EARLY EMBRYO DEVELOPMENT

2016 ◽  
Vol 28 (2) ◽  
pp. 210
Author(s):  
P. Hugon ◽  
J. Lamy ◽  
E. Corbin ◽  
P. Mermillod ◽  
M. Saint-Dizier
Keyword(s):  
Corpus Luteum ◽  
Embryo Development ◽  
Zona Pellucida ◽  
Developmental Stages ◽  
Early Embryo ◽  
Developmental Competence ◽  
Control Group ◽  
Vitro Fertilization ◽  
Oviductal Fluid

This study was designed to evaluate the effects of oviductal fluid at different periovulatory times on oocyte maturation, modification of the zona pellucida (ZP), fertilization and embryo development. Bovine oviducts were collected at a slaughterhouse and classified as preovulatory (pre-ov: 1 pre-ov follicle and a regressing corpus luteum) or post-ovulatory (post-ov: a corpus haemorrhagicum or recent corpus luteum; n = 10 cows/stage). Both oviducts were flushed with 1 mL of sterile TCM-199, and oviductal flushes (OF) were aliquoted and stored at –80°C. Abattoir-derived bovine ovaries were aspirated and cumulus‐oocyte complexes (COC) with at least 3 cumulus layers and homogeneous oocyte cytoplasm were in vitro matured for 22 h in standard maturation medium (control group, n = 319) or in standard medium with 2× concentrated additives supplemented (50% v/v) with pre-ov OF (n = 255) or post-ov OF (n = 248). After in vitro maturation (IVM), subgroups of COC were denuded, and the time of digestion of the ZP by pronase 0.1% (v/v in TCM-199) was determined to evaluate ZP hardening. After IVM, COC were fertilised in vitro for 18–20 h at a final concentration of 1.106 million spermatozoa (spz)/mL. After in vitro fertilization (IVF), COC were denuded, washed twice and cultured for 8 days more under standard conditions. After IVM, IVF, and embryo culture, oocytes/embryos were fixed with ethanol, stained with Hoescht, and examined under fluorescence microscopy for determination of (1) maturation and developmental stages, (2) numbers of fertilised and polyspermic oocytes, and (3) spz bound to the ZP. Percentages were compared between groups by chi-square. Times of ZP digestion were compared by Kruskal‐Wallis test. Numbers of spz bound to the ZP were compared by ANOVA on normalised data followed by Newman-Keuls tests. Data are presented as mean ± SEM. A P < 0.05 was considered significant. Addition of OF during IVM had no effect on maturation rates compared with the control. However, the digestion time of the ZP by pronase was reduced after IVM with pre-ov OF (313 ± 21 s; n = 26) compared with post-ov OF (459 ± 23 s; n = 23) but not with the control (416 ± 30 s; n = 25). After IVF, the number of spermatozoa bound to the ZP was increased after IVM with pre-ov OF (57 ± 5 spz/oocyte; n = 67) and decreased after IVM with post-ov OF (34 ± 3 spz/oocyte; n = 76) compared with the control (42 ± 5 spz/oocyte; n = 60). Addition of OF during IVM had no effect on rates of IVF and polyspermia. However, the rate of development to the blastocyst stage was less after IVM with post-ov OF (10%, n = 97 cleaved oocytes) compared with control (24%, n = 130) and pre-ov OF (29%, n = 101). In conclusion, the OF collected before ovulation decreased the resistance of the ZP to protease digestion and increased its ability to bind spz, whereas it was the opposite for the post-ov OF. Furthermore, the post-ov OF decreased the developmental competence of fertilised oocytes.

134 CYSTEINE AND CATALASE SUPPLEMENTATION FOR 7 DAYS DURING IN VITRO CULTURE IMPAIRS BOVINE EMBRYO DEVELOPMENT

2013 ◽  
Vol 25 (1) ◽  
pp. 214
Author(s):  
B. C. S. Leão ◽  
N. A. S. Rocha ◽  
M. F. Accorsi ◽  
É. Nogueira ◽  
G. Z. Mingoti
Keyword(s):  
In Vitro Culture ◽  
Embryo Development ◽  
Cellular Proliferation ◽  
Mitochondrial Respiratory Chain ◽  
Organic Peroxide ◽  
Redox Status ◽  
Culture Period ◽  
Bovine Embryo ◽  
Embryo Survival

The production of reactive oxygen species (ROS), such as superoxide anion (O2–), hydroxyl radical (OH–), hydrogen peroxide (H2O2) and organic peroxide, is a normal process that occur in the cellular mitochondrial respiratory chain (Morado et al. 2009 Reprod. Fert. Dev. 21, 608–614). Supplementation with antioxidants during in vitro culture (IVC) appears to increase the resistance of bovine embryos to the oxidative stress, and consequently improve embryo development and cryotolerance (Rocha et al. 2011 Reprod. Fert. Dev. 23 157–158). This study was conducted to evaluate the effects of period of supplementation with intra (cysteine, CIST) or extracellular (catalase, CAT) antioxidants during IVC on embryo development and cryotolerance. Cumulus–oocyte complexes (n = 1132) were maturated for 24 h in B199 medium, at 38.5°C and 5% CO2 in air. After fertilization (Day 0), zygotes were IVC for 7 days in SOF medium (0.5% BSA + 2.5% FCS) in 7% O2, 5% CO2 e 88% N2 atmosphere, at 38.5°C. The antioxidant supplementation was performed during all of the culture period (from Day 1 to Day 7) or during the first 72 h (from Day 1 to Day 3), with 0.6 mM CIST, 100 UI CAT or without antioxidants (CONTR). The cleavage and blastocyst rates were evaluated, respectively, at 72 and 168 h post-insemination, when expanded blastocysts grade I were vitrified (n = 91) by Vitri-Ingá® protocol (Ingámed®, Maringá, PR, Brazil). Then, they were thawed and cultured for 24 h to evaluate re-expansion rates. The differences between groups were analyzed by ANOVA followed by Tukey’s test, and re-expansion rates by chi-square test (P ≤ 0.05). The cleavage and blastocyst rates were, respectively, 83.52 ± 4.52a/36.19 ± 3.21a (CONTR), 79.16 ± 4.52a/38.08 ± 3.21a (CIST Day 3), 77.74 ± 4.52a/42.09 ± 3.21a (CAT Day 3), 73.57 ± 4.05a/11.15 ± 2.87b (CIST Day 7), 71.83 ± 4.05a/15.07 ± 2.87b (CAT Day 7). The embryo re-expansion rates were 90.00%a (CONTR), 93.33%a (CIST Day 3), 75.00%a (CIST Day 7), 63.64%a (CAT Day 3) and 75.00%a (CAT Day 7). Supplementation with antioxidants for 7 days of IVC impaired embryo development, compared with addition up to Day 3 (P ≤ 0.05). However, it did not affect in vitro embryo cryotolerance (P ≥ 0.05). Supplementation with antioxidants throughout all the IVC significantly impaired blastocyst rate, probably by exerting a toxic effect leading to an arrest of embryonic development. It is believed that prolonged culture in the presence of antioxidants results in excessive reduction of ROS leading to an imbalance of the cellular redox status. It is known that ROS, particularly H2O2, act on signaling pathways involved in the cellular proliferation and differentiation, in gene expression and metabolism during embryo development. Supplementation with antioxidants up to Day 3 did not differ from CONTR, probably due to low O2 tension, and the presence of antioxidants in FBS and BSA. In conclusion, supplementation with cysteine and catalase during all of the culture period impaired embryo development, however this reduction did not affect embryo survival after vitrification. Financial support was provided by FAPESP (#2011/18257-2). The authors acknowledge Ingámed, Alta Genetics Brazil.

100 EMBRYO SURVIVAL AND CONCEPTUS ELONGATION FOLLOWING ASYNCHRONOUS EMBRYO TRANSFER IN CATTLE

2015 ◽  
Vol 27 (1) ◽  
pp. 143
Author(s):  
F. Randi ◽  
B. Fernandez ◽  
M. McDonald ◽  
C. Johnson ◽  
N. Forde ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Prostaglandin F2α ◽  
Early Embryo ◽  
Embryo Survival ◽  
Treatment Groups ◽  
Length Data ◽  
Uterine Environment ◽  
To Receive ◽  
Intravaginal Device

Maternal progesterone (P4) regulates early conceptus growth and development in ruminants. Early embryo transfer studies in sheep and cattle demonstrated a need for close synchrony between the embryo and the uterine environment of the recipient. However, manipulating P4 may be one way of strategically regulating the temporal changes that normally occur in the uterine environment in order to allow flexibility in the timing of embryo transfer. For example, previous studies have demonstrated that P4 administration during the first few days of the oestrous cycle facilitates pregnancy establishment with older embryos. The aim of this study was to examine the effect of embryo-uterine synchrony on conceptus elongation in cattle. Oestrous cycles of crossbred beef heifers were synchronised using an 8-day P4-Releasing Intravaginal Device (PRID Delta®, CEVA, Mountain View, CA, USA) with administration of a prostaglandin F2α analogue (Enzaprost®, CEVA; 5 mL equivalent to 25 mg of dinoprost) given on the day before PRID removal. Heifers were checked for signs of oestrus 4 times per day commencing 30 h after PRID withdrawal. Only those seen in standing oestrus (n = 50) were randomly assigned to 1 of 5 treatment groups to receive Day 7 in vitro-produced blastocysts (n = 10 per recipient) (1) on Day 5 post-oestrus; (2) on Day 5, with P4 supplementation via PRID from Day 3 to 5 + 750 IU of eCG at PRID insertion; (3) on Day 5, PRID Delta from Day 3 to 5 plus 3000 IU of hCG at PRID insertion; (4) on Day 7, or (5) on Day 9. At embryo age Day 14, all heifers were slaughtered and the uterus was flushed to recover and measure conceptuses. Data are summarised in Table 1. Fewer recipients yielded conceptuses (P < 0.05) and fewer conceptuses overall were recovered (P < 0.05) following transfer on Day 5 compared with Day 7 or Day 9. Supplementation with P4 resulted in short cycles (evidenced by corpus luteum regression and/or a recent ovulation at slaughter) in 33.3 to 54.5% of recipients receiving embryos on Day 5. Mean conceptus length was greater (P < 0.05) following transfer to an advanced uterus. In conclusion, transfer of embryos to a retarded (Day 5) uterine environment results in poor embryo survival. Supplementation with P4 shortened the interoestrous period in a significant number of heifers. Transfer to an advanced uterine environment promotes conceptus elongation, presumably driven by P4. Table 1.Embryo survival and conceptus length data

Does prostacyclin (PGI2) support porcine corpus luteum function? – data from in vitro study

2016 ◽  
Vol 62 (5) ◽  
pp. 49
Author(s):  
Magdalena Julia Szymańska ◽  
Agnieszka Blitek
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Corpus Luteum ◽  
Estrous Cycle ◽  
In Vitro Study ◽  
Luteal Cells ◽  
Enzymatic Isolation ◽  
Effective Doses ◽  
And Function

Background. Prostacyclin (PGI2) of luteal origin is involved in the control of corpus luteum (CL) development and function in cattle. PGI2 may regulate the process of angiogenesis and may stimulate progesterone (P4) secretion by luteal cells via its specific receptors, PTGIR. In contrast to cattle, the role of PGI2 in the pig CL has not yet been described.Aim. The present study aimed to investigate the effect of PGI2 on 1) P4 secretion by luteal cells, and 2) the expression of angiogenesis-related genes in endothelial cells of the porcine CL.Methods. CL collected from gilts on day 5-7 of the estrous cycle were used for enzymatic isolation of luteal (Experiment 1) and endothelial (Experiment 2) cells. In Exp. 1, cultured luteal cells were incubated with increasing (0, 0.01, 0.1, 1, 5 µM) doses of PGI2 analogues: iloprost (ILO) and carbaprostacyclin (cPGI2) for 8 h. To determine the effective doses of PGI2 analogues, P4 concentration in culture medium was examined by RIA. Thereafter, luteal cells were treated with ILO and cPGI2 at the concentration of 1 and 5 µM in the presence or absence of PTGIR antagonist (CAY10441). After 8 h of incubation the medium was collected for P4 determination. In Exp. 2, isolated endothelial cells were treated for 24 h with ILO and cPGI2 at doses of 1 and 5 µM. Then, cells were collected for analysis of Ang-1 and -2 mRNA expression using qPCR.Results. Both, ILO and cPGI2 affected P4 secretion by luteal cells. Elevated levels of P4 were observed in medium after treatment of luteal cells with 1 µM of ILO and 0.1, 1 and 5 µM of cPGI2 compared with control values (p<0.05). The addition of CAY10441 inhibited the stimulatory effect of ILO on P4 secretion, while did not change P4 production by luteal cells incubated with cPGI2. Moreover, PGI2 analogues differentially affected (p<0.05) the expression of proangiogenic factors. ILO stimulated Ang-2, whereas cPGI2 positively affected Ang-1 mRNA expression in endothelial cells at concentrations of 1 µM and 5 µM, respectively.Conclusion. PGI2 affects P4 secretion during luteal phase of the estrous cycle and may regulate the process of angiogenesis in the porcine CL.

Sign in / Sign up

Export Citation Format

Share Document