Cryotolerance of in vitro-produced porcine blastocysts is improved when using glucose instead of pyruvate and lactate during the first 2 days of embryo culture

2013 ◽  
Vol 25 (5) ◽  
pp. 737 ◽  
Author(s):  
M. Castillo-Martín ◽  
M. Yeste ◽  
R. Morató ◽  
T. Mogas ◽  
S. Bonet

The objective of the present study was to determine the effects of replacing glucose with pyruvate and lactate during the first 48 h of in vitro culture (IVC) in NCSU-23 medium on embryo development, embryo quality and survival of porcine blastocysts after vitrification. To this end, in vitro-produced (IVP) porcine oocytes were cultured with either glucose for 6 days (IVC-Glu) or pyruvate–lactate from Day 0 to Day 2 and then with glucose until Day 6 (IVC-PyrLac). Blastocysts were vitrified on Day 6 using the Cryotop device and, after warming, survival rate and the apoptosis index were evaluated after 24 h incubation in NCSU-23 medium. No significant differences were observed between IVC-Glu and IVC-PyrLac in terms of cleavage rate, blastocyst yield, total number of cells per blastocyst or the apoptosis index (1.82 ± 0.75% vs 3.18 ± 0.88%, respectively) of non-vitrified embryos. However, a significant increase was seen in hatching/hatched blastocysts in the IVC-PyrLac compared with IVC-Glu treatment group (12.71 ± 1.20% vs 3.54 ± 0.47%, respectively). Regardless of treatment, vitrification impaired the survival rate and the apoptosis index. When comparing both treatments after warming, the percentage of apoptotic cells was significantly higher for blastocysts in the IVC-PyrLac compared with IVC-Glu group (18.55 ± 3.49% vs 9.12 ± 2.17%, respectively). In conclusion, under the conditions of the present study, replacement of glucose with pyruvate–lactate during the first 48 h of culture resulted in a lower cryotolerance of IVP porcine embryos.


2021 ◽  
Vol 33 (2) ◽  
pp. 178
Author(s):  
P. R. Cruzans ◽  
M. S. Lorenzo ◽  
G. M. Teplitz ◽  
C. G. Luchetti ◽  
D. M. Lombardo

l-Carnitine (LC) plays an important role in the catabolism of lipids and protects cells from the damage caused by reactive oxygen species due to its antioxidant activity. The aim of this study was to evaluate the effect of adding different concentrations of LC during porcine invitro maturation on embryo quality and development. The cumulus–oocyte complexes were obtained by follicular aspiration from ovaries of slaughtered sows and matured invitro for 44h without LC (control) or with different concentrations of LC (0.6 or 1.25mg mL−1) (Sigma-Aldrich) in TCM-199 supplemented with human menopausal gonadotrophin and cyclic AMP (cAMP) during the first 22h. Invitro fertilization was performed with fresh boar semen for 4h in 100-µL drops of TCM-199 with caffeine, bovine serum albumin, sodium lactate, and pyruvate (20 denuded oocytes per drop, 1×106 spermatozoa mL−1). Presumptive zygotes were washed and cultured in NCSU 23 at 39°C, 7% O2, 5% CO2, and humidity. The cleavage rate was registered on Day 2 and the blastocyst rate on Day 7. Embryo quality was assessed by counting the number of cells per blastocyst (Hoescht 33342) and late apoptosis index (TUNEL-positive cells/total cells). Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) was performed according to the kit protocol (Roche). LC significantly decreased the cleavage rate (control: 46.2%; LC0.6: 32.1%; LC1.25: 37.9%; P<0.05, Chi-squared test). No significant differences were detected in the blastocyst rate (control: 19.2%; LC0.6: 17%; LC1.25: 10,2%, Chi-squared test) or in number of cells per blastocyst (control: 51.97±3; LC0.6: 56.11±4; LC1.25: 45.62±4, ANOVA). There was embryo hatching in LC treatments but not in the control (control: 0%, LC0.6: 11%; LC1.25: 7.6%). The apoptosis index decreased in LC1.25 compared with LC0.6 (Control: 7,6±1.3%; LC0.6: 10±1.1%; LC1.25: 5,5±0.8%; P<0.05, ANOVA) but there was no significant difference in the apoptosis index between control and LC treatments. In conclusion, LC treatments decreased the cleavage rate but did not modify the blastocyst rate and allowed embryo hatching.



2011 ◽  
Vol 23 (1) ◽  
pp. 168 ◽  
Author(s):  
M. V. Suárez Novoa ◽  
S. Di Francesco ◽  
M. Rubessa ◽  
L. Boccia ◽  
V. Longobardi ◽  
...  

The current knowledge on metabolism and glucose utilisation of preimplantation bovine and ovine embryos suggest the reduction of glucose concentration during early culture. On the contrary, it has been demonstrated that glucose is absolutely required for in vitro culture of buffalo embryos, as indicated by the poor efficiency recorded in the absence of this substrate during early embryonic development (Monaco et al. 2006 Reprod. Domest. Anim. 41, 332). However, complete removal of glucose from culture medium throughout pre-elongation development is unlikely to benefit the embryo because glucose plays other roles including ribose and NADPH production through the pentose-phosphate pathway. Therefore, the aim of this study was to investigate the effect of reducing glucose concentration up to 0.15 mM (1/10 compared to the standard concentration in SOF) on embryo development in buffalo. In order to evaluate the role of this substrate during development, glucose was reduced at different stages of embryo culture. Cumulus–oocyte complexes (n = 573, over 4 replicates), recovered from slaughtered animals, were matured and fertilized in vitro according to our standard procedures (Gasparrini et al. 2006, Theriogenology, 65, 275–287). On day 1 (Day 0 = IVF), zygotes were cultured in SOF with group A) 1.5 mM glucose (standard concentration in SOF) throughout culture (control); group B) 1.5 mM glucose for early culture (Day 1 to Day 4) and 0.15 mM glucose for late culture (Day 4 to Day 7); group C) 0.15 mM glucose throughout culture; and group D) 0.15 mM glucose for early culture and 1.5 mM glucose for subsequent culture. In vitro culture was carried out at 38.5°C under 5% CO2, 7% O2, and 88% N2. Cleavage rate was evaluated on Day 4, and blastocyst yield, in relation to cleaved embryos, was recorded on Day 7. Differences among groups in blastocyst rate were analysed by chi-square test. The reduction of glucose concentration did not affect cleavage rate (73.7 v. 65.1%, respectively, for Groups A-B and C-D). Nevertheless, blastocyst rates significantly decreased when glucose was reduced throughout culture (Group C: 10.1%; P < 0.01) and to a limited degree during early culture (Group D: 17.2%; P < 0.05) compared with the control (Group A: 38.3%). On the contrary, a decreased glucose concentration during late culture did not reduce embryo development (Group B: 35.18%). This finding indicates that energy requirements of buffalo embryos during IVC are different from those of sheep and cattle, which show a significant rise in glucose uptake just around compaction, i.e. during late culture (Thompson et al. 1991 Reprod. Fertil. Dev. 3, 571–576; Thompson et al. 1996 J. Reprod. Fertil. 106, 299–306). In conclusion, in buffalo, unlike sheep and cattle, glucose is more critical for early embryo development than for post-compaction development, suggesting the importance of developing other strategies for optimizing in vitro embryo production efficiency.



2009 ◽  
Vol 21 (1) ◽  
pp. 156
Author(s):  
E. Dovolou ◽  
M. Clemente ◽  
G. S. Amiridis ◽  
I. Messinis ◽  
A. Kalitsaris ◽  
...  

We have previously shown that follicular and oviductal fluid provide greater total protection against lipid peroxidation than the respective media used for the in vitro embryo production. Reactive oxygen species (ROS) production has been implicated as a major cause for the reduced in vitro bovine embryo production; it is believed that they participate in meiotic arrest of oocytes, embryonic block and cell death. The aim of this study was to determine whether guaiazulene (G), an exogenous antioxidant, added in the post fertilization culture medium would affect the early embryo development and the quality of the produced blastocysts in terms of mRNA expression of several important genes. In a previous study we had shown that media modified with 0.01 mm of G provided the same antioxidant protection as the respective in vivo environments (i.e. the follicular and the oviductal fluid). Bovine cumulus–oocyte complexes (COC) were aspirated from ovaries derived from slaughtered cows and matured in groups of 50 in 500 μL in TCM199 with 10% fetal calf serum and 10 ng mL–1 Epidermal Growth factor at 39°C in an atmosphere of 5% CO2 in air and maximum humidity. Twenty-four hours later matured oocytes were inseminated with frozen/thawed bull semen and co-incubated in the same conditions as maturation. Presumptive zygotes were divided into 4 groups and cultured in groups of 25 in 25 μL of SOF with 5% FCS (Control–, n = 355), supplemented with 0.01 mm of G (n = 344) or 0.1 mm of G (n = 345) or 0.05% DMSO – the G diluent–(Control+, n = 347) at 39°C in an atmosphere of 5% CO2, 5% O2 and maximum humidity. Blastocyst yield was recorded on Days 6, 7, 8 and 9; Day 7 blastocysts from each group were snap frozen and stored at –80°C for mRNA extraction. Quantification of transcripts for aldose reductase mRNA (AKRIBI), prostaglandin G/H synthase-2 (PGHS-2, COX-2), glyceraldehyde 3-phosphate dehydrogenase (GADPH), facilitated glucose/fructose transporter, member 5 (GLUT-5) genes related to metabolism, glutathione peroxidase 1 (GPX1), glucose-6-phosphate dehydrogenase (G6PD) antioxidant enzymes and placenta-specific 8 (PLAC8) related to implantation was carried out by real-time quantitative RT-PCR. Data for embryo development and on transcript abundance were analyzed by chi square and ANOVA, respectively. Cleavage rate tended to be higher in 0.01 mm group than in Control– (77.87% v. 71.41%, P = 0.07). Barring that, no other differences were detected in cleavage rate (Control+: 71.32%; 0.1 mm: 72.75%) or in the overall blastocyst yield on Day 9 (Control–: 25.50%; Control+: 26.71%; 0.1 mm: 25.75%; 0.01 mm: 29.58%). The relative abundance of genes studied varied among groups, but these differences were not significant. We infer that under the current culture conditions, G as an antioxidant has no serious direct effect on early embryo development or on embryo quality at least on the mRNA transcripts studied. Further studies using the same antioxidant in different atmospheric conditions are planed. ED and GSA were sponsored by COST (FAO702) and OECD fellowships, respectively.



2012 ◽  
Vol 24 (1) ◽  
pp. 138
Author(s):  
L. Boccia ◽  
M. Rubessa ◽  
M. De Blasi ◽  
S. Di Francesco ◽  
G. Albero ◽  
...  

Although in vitro embryo production efficiency in buffalos has greatly improved over the years, the in vitro-produced embryos show lower viability and resistance to cryopreservation. Therefore, it is necessary to optimize the in vitro culture conditions to improve embryo quality. Hyaluronic acid, a glycosaminoglican present in oviducal and uterine fluids, has been shown to successfully support in vitro development of bovine embryos (Stojkovic et al. 2002 Reproduction 124, 141–153). The aim of this study was to evaluate the influence of high concentrations of hyaluronic acid (HA) during late in vitro culture on blastocyst development, as well as on their cryotolerance after cryotop vitrification in buffalos. In vitro matured and fertilized buffalo oocytes (n = 1007) from slaughterhouse ovaries were cultured for 4 days in SOFaa supplemented by 8 mg mL–1 of BSA in a controlled gas atmosphere consisting of 5% CO2, 7% O2 and 88% N2, in humidified air, at 38.5°C. On Day 4, cleavage rate was assessed (75.2%) and all of the cleaved elements were divided into 3 different late culture groups: 8 mg mL–1 of BSA (n = 244; group A), 8 mg mL–1 of BSA supplemented by 6 mg mL–1 of HA (n = 251; group B) and 1 mg mL–1 of BSA supplemented by 6 mg mL–1 of HA (n = 262; group C). On Day 7 after IVF, embryo outcome was assessed and all of the embryos were vitrified by cryotop [De Rosa et al. 2007 Ital. J. Anim. Sci. 6 (Suppl 2), 747–750] and cultured for 24 h. The resistance to cryopreservation was evaluated by assessing the survival rate on the basis of morphological criteria and the percentage of embryos reaching a more advanced developmental stage after 24 h culture. Data were analysed by the chi-square test. No differences in blastocyst rate were recorded among groups (43.9, 44.3 and 40.0%, respectively in A, B and C groups). However, out of the total embryos, a higher percentage of Grade 1 hatched blastocysts (Robertson and Nelson 1998 Manual of the International Embryo Transfer Society 9, 103–16) was observed in group C (P < 0.05) than in groups A and B (14.3, 18.8 and 25.5% in A, B and C groups, respectively). Although the supplementation with HA did not improve the survival rates following vitrification-warming (51.1, 59.4 and 58.4% in A, B and C groups, respectively), the percentage of vitrified-warmed embryos that resumed development and reached a more advanced developmental stage after culture increased (P < 0.01) in group C (20.7, 27.7 and 37.6% in A, B and C groups, respectively). In conclusion, the addition of 6 mg mL–1 of HA, together with a limited protein source (i.e. 1 mg mL–1 of BSA), during late culture improved buffalo embryo quality, indicated by both the greater percentage of advanced-stage embryos and by the resumption of development after post-warming culture.



2021 ◽  
Vol 33 (2) ◽  
pp. 139
Author(s):  
M. S. Lorenzo ◽  
G. M. Teplitz ◽  
P. R. Cruzans ◽  
C. G. Luchetti ◽  
J. Ghersa ◽  
...  

The oviduct is involved in many reproductive functions, including early embryo development. The epithelial cells that cover the oviduct produce oviducal fluid and could be used to recreate the invivo environment into which embryo development takes place. This study aimed to evaluate the co-culture of porcine embryos with a monolayer of porcine oviducal epithelial cells (POEC) and its effect on embryo development and quality. The POEC were obtained by pressing the isthmus (from diestrus sow oviducts) using slides and performing 3 cycles of vortexing and decanting in DMEM-F12 medium. Passage 1 cells were used for these experiments (POEC-1). Oocytes were obtained from follicular aspiration of slaughterhouse ovaries. Oocytes were invitro matured for 44h in TCM-199 supplemented with human menopausal gonadotrophin and cyclic AMP during the first 22h. Invitro fertilization was performed with 17°C-refrigerated boar semen for 4h in 100-µL drops of TCM-199 with caffeine, bovine serum albumin, sodium lactate, and sodium pyruvate (20 denuded oocytes per drop, 1×106 spermatozoa mL−1). Presumptive zygotes were washed and randomly assigned to one of the following groups for invitro culture: control (50-µL drop of NCSU-23 with sodium pyruvate and lactate), POEC-1 (same as the control+POEC-1 50 000 cells mL−1), POEC-1+FBS (same as the control+POEC-1 50 000 cells mL−1 and 2.5% of fetal bovine serum). Culture conditions were 7% O2, 5% CO2, 39°C, and humidity. On Day 2, the cleavage rate was recorded, and embryos were transferred to NCSU-23 drops with glucose and without cells. The blastocyst rate was recorded on Day 7. Embryo quality was assessed by counting the number of cells per blastocyst (Hoechst) and the apoptosis index (TUNEL-positive cells/total cells). Co-culture with POEC-1 significantly increased the blastocyst rate (control: 14%; POEC-1+FBS: 10%; POEC-1: 28%; P&lt;0.05 Chi-squared test) and allowed embryo hatching (control: 0; POEC-1+FBS: 22.2%; POEC-1: 7; P&lt;0.05 Chi-squared test). However, there was no significant difference in the number of cells per blastocyst (control: 58.6±6; POEC-1+FBS: 50.3±3.7; POEC-1: 50.6±4.8; nonparametric ANOVA) or in the apoptosis index (control: 8.1; POEC+FBS 8.3; POEC: 7.4; nonparametric ANOVA). The use of POEC-1 during the first 2 days of embryo culture enhanced embryo development and improved culture conditions, allowing embryo hatching. The effect on embryo development could be due to an effect of POEC itself or the effect of feeder cells. Other parameters of embryo quality should be evaluated in the future.



2016 ◽  
Vol 28 (2) ◽  
pp. 139
Author(s):  
C. Buemo ◽  
A. Gambini ◽  
L. Moro ◽  
R. F. Y. Martin ◽  
D. Salamone

In this study, we analysed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst size and cell number, DNA fragmentation levels by TUNEL assay, and the relative expression of genes associated with pluripotency, apoptosis, trophoblast markers, and DNA methylation in the porcine. Cumulus-oocyte complexes were recovered from slaughterhouse ovaries by follicular aspiration. Maturation was performed in TCM for 42 to 48 h at 39°C and 5% CO2. After denudation by treatment with hyaluronidase, mature oocytes were stripped of the zona pellucida using a protease and then enucleated by micromanipulation; staining was performed with Hoëchst 33342 to observe metaphase II. Ooplasms were placed in phytohemagglutinin to permit different membranes to adhere between each other; the ooplasm membrane was adhered to a porcine fetal fibroblast from an in vitro culture. Adhered membranes of the donor cell nucleus and enucleated oocyte cytoplasm were electrofused through the use of an electric pulse (80 V for 30 μs). All reconstituted embryos were electrically activated using an electroporator in activation medium (0.3 M mannitol, 1.0 mM CaCl2, 0.1 mM MgCl2, and 0.01% polyvinyl alcohol) by a DC pulse of 1.2 kVcm for 80 μs. Then, embryos were incubated in 2 mM 6-DMAP for 3 h. In vitro culture of zona-free embryos was achieved in a well of wells system in 100 μL of SOF medium. Two experimental groups were used, one control group with a single reconstructed embryo per microwell (1×) and the other group placing 3 reconstructed embryo per microwell (3x aggregation group). Embryos were cultivated at 39°C in 5% O2, 5% CO2 for 7 days in SOF medium with a supplement of 10% fetal bovine serum on the fifth day. At Day 7, resulting blastocysts were classified according to their morphology and diameter to determine their quality. Our results showed that aggregation of 3× embryos increased blastocyst formation rate and blastocyst size of pig cloned embryos (Fisher’s test P < 0.05 and Student’s t-test P < 0.05, respectively). The DNA fragmentation levels in 3× aggregated cloned blastocysts were significantly decreased compared to 1x blastocyst (Student’s t-test P < 0.05). Levels of Oct4, Klf4, Igf2, Bax, and Dnmt1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially nondetectable (Student’s t-test P < 0.05). Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.



2017 ◽  
Vol 29 (1) ◽  
pp. 183 ◽  
Author(s):  
T. A. Patrocínio ◽  
C. A. C. Fernandes ◽  
L. S. Amorim ◽  
J. R. Ribeiro ◽  
G. C. Macedo ◽  
...  

Oxidative stress is one of the main effects of in vitro culture. Generation of reactive oxygen species (ROS) by embryos can be enhanced by the sub-optimal in vitro culture conditions and are associated with a delay in embryonic development. However, supplementation of culture medium with antioxidant agents can minimize the effects of ROS (Guérin et al. 2001 Hum. Reprod. Update 7, 175–189). Resveratrol is an example of a potent antioxidant, and modifications in its structure can improve its biological activity. This study evaluated the effect of AR33 (formula with patent pending), an analogue of resveratrol with high antioxidant activity, on embryo development. Bovine cumulus-oocyte complexes recovered from ovaries collected at the slaughterhouse were in vitro matured for 24 h and oocytes were in vitro fertilized for 20 h, both at 38.8°C under 5% CO2 in air and high humidity. Partially denuded presumptive zygotes were randomly distributed in 4 treatments (with 6 replicates): 0 µM (control, n = 347), 0.1 µM (n = 337), 0.5 µM (n = 277), and 2.5 µM (n = 343) of AR33. The base medium was SOFaa supplemented with 2.5% FCS and incubation conditions were 38.8°C under 5% CO2 in air and high humidity. Half of culture medium was renewed (feeding) at Day 3 and 5 post-fertilization. Cleavage was evaluated at Day 3 and blastocyst rates at Day 7 and 8 post-fertilization. Data were analysed by logistic regression considering the significance level of P < 0.05. Values are shown as mean ± SEM. Cleavage rate was higher (P < 0.05) for 2.5 µM (69.0 ± 4.4%) than for 0, 0.1, and 0.5 µM AR33 (62.1 ± 2.0%, 60.7 ± 5.9%, and 56.7 ± 5.8%, respectively). At Day 7, the blastocyst rate was similar (P > 0.05) among 0.1, 0.5, and 2.5 µM (18.1 ± 5.4%, 17.5 ± 2.9%, and 19.4 ± 3.3%, respectively) and all of them were higher (P < 0.05) than 0 µM AR33 (12.4 ± 2.5%). At Day 8, there was again no difference (P > 0.05) among 0.1, 0.5, and 2.5 µM AR33 (21.0 ± 5.0%, 18.4 ± 2.1%, and 24.6 ± 3.3%, respectively) but only 0.1 and 2.5 µM showed higher (P < 0.05) blastocyst rate than 0 µM AR33 (15.2 ± 2.5%). In conclusion, the synthetic analogue of resveratrol tested in this study can improve bovine embryo development in culture medium supplemented with 2.5% FCS under 5% CO2 in air. A concentration of 2.5 µM AR33 can be a choice for further studies. This study was supported by Fapemig, CAPES, and CNPq.



2013 ◽  
Vol 25 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Castillo-Martín ◽  
M. Yeste ◽  
R. Morató ◽  
T. Mogas ◽  
S. Bonet

The benefits of adding l-ascorbic acid during the cryopreservation procedure have been reported before in mouse and bovine. In this study, the effects of l-ascorbic acid (AC) supplementation during culture, cryopreservation, or both procedures on the developmental ability and embryo quality of in vitro produced porcine blastocysts were examined. Embryo quality criteria consisted of total cell number, percentage of apoptosis, and cryotolerance. After in vitro fertilisation, presumptive zygotes were randomly assigned to 2 culture treatments in which the culture medium NCSU23 was supplemented with 100 µM AC (n = 1162) or nonsupplemented (n = 1163) for a 144-h period. On Day 6, blastocyst formation was assessed by stereomicroscopy, and a representative fraction of Grade I- and II-blastocysts of each culture treatment was evaluated using 4′,6-diamidino-2-phenylindole-TUNEL co-staining and considered as fresh-control. The remaining fraction of Grade I- and II-blastocysts was vitrified/warmed following the Cryotop® method. To determine the effect of AC supplementation during cryopreservation procedures, each culture treatment was divided into 2 groups: (1) embryos exposed to 100 µM AC, and (2) nonexposed embryos (vitrified-control). Survival was determined according to reexpansion rates after 24 h of recovery in NCSU23 medium. After 24 h, reexpanded blastocysts were co-stained using the 4′,6-diamidino-2-phenylindole-TUNEL technique, and total number of cells and apoptosis indexes were determined. Experiment was replicated 9 times for each group. Data were analyzed by t-test for independent variables and a 2-way ANOVA. Results are expressed as means ± SE, and the significant level was set at 5% (Table 1). After culture, supplementing NCSU23 medium with AC showed no significant differences in blastocyst formation (fresh-control 11.6 ± 7.8 v. AC 11.6 ± 7.7), in number of cells (fresh-control 36.7 ± 15.8 v. AC 36.1 ± 15.9), or in apoptosis index (fresh-control 2.9 ± 5.7 v. AC 3.5 ± 4.7). On the other hand, only when both culture and vitrified media were supplemented with AC was there a significant increase of blastocyst survival. In contrast, no significant differences in embryo survival were observed when only 1 of these 2 media (culture or vitrification) was supplemented. Supplementing culture media or cryopreservation solutions with AC did not affect the total cell number or apoptosis index in vitrified blastocysts. In conclusion, the addition of 100 µM l-ascorbic acid to the culture and cryopreservation solutions improves the cryotolerance of in vitro-produced porcine blastocysts. Table 1.Survival of blastocysts (24 h), total cell number, and percentage of apoptosis after vitrification/warming



2011 ◽  
Vol 23 (1) ◽  
pp. 150
Author(s):  
J. Sanchez-Osorio ◽  
C. Cuello ◽  
J. Gomis ◽  
C. Maside ◽  
M. A. Gil ◽  
...  

The aim of this study was to design a chemically defined medium for the vitrification of in vitro produced porcine blastocysts avoiding the use of serum or serum components. Cumulus–oocyte complexes were matured in vitro in NCSU-23 for 44 h and were inseminated with frozen–thawed spermatozoa. Presumptive zygotes were cultured for 16 h to assess in vitro fertilization (IVF) parameters (N = 200) or for 6 days (N = 600) in order to obtain blastocysts. For chemically delipidation, 10 μM forskolin was added to the culture medium on Day 5 of in vitro culture. On Day 2, embryos were evaluated for cleavage rate. On Day 6, embryos were assessed for blastocyst formation; only those blastocysts showing excellent morphological appearance were selected for vitrification. Blastocysts were vitrified using as basic medium TCM-199 HEPES supplemented with 20% of newborn calf serum (NBCS; n = 65), with 0.1% of polyvinyl alcohol (PVA; n = 64) or without additives (WA; n = 65). The OPS-vitrification and warming were performed as described by (Sanchez-Osorio et al. 2010 Theriogenology 73, 300–308) using 16% of Etylenglycol and 16% of dimetyl sulfoxide as final concentrations of cryoprotectants. Vitrified blastocysts were warmed and cultured in vitro for 24 h to assess their viability. Blastocysts that totally reformed their blastocoel cavity showing a normal or excellent morphology were considered viable. In addition, after in vitro culture vitrified-warmed viable embryos were fixed in 4% paraformaldehyde in PBS medium and stained with Hoechst 33342 in order to assess the total number of cells. Data were analysed by using the MIXED procedure of SPSS. The threshold for significance was set at P < 0.05. Results are expressed as least squares means ± SEM. The maturation, penetration, and monospermy rates were 98.5 ± 1.2%, 85.3 ± 3.6%, and 48.8 ± 5%, respectively. The efficiency of IVF (defined as the ratio of monospermic oocytes to the total number of inseminated oocytes) was 41.0 ± 4.9%. The values of cleavage rate at Day 2 and blastocysts formation rate were 67.8 ± 1.4% and 37.3 ± 1.6%, respectively. After vitrification and warming, similar survival rates were observed for NBCS (33.8 ± 5.9) PVA (40.6 ± 6.0), and WA (30.8 ± 5.9) groups. No significant differences were found for the total number of cells (ranged from 35.4 ± 6.8 to 50.8 ± 8.3) among vitrification groups. In conclusion, in vitro derived porcine blastocysts can be vitrified in the absence of serum and serum components. Furthermore, PVA is a suitable substitute for serum in vitrification solutions with no detrimental effect on the viability of in vitro produced pig blastocysts. This study was supported by the Seneca foundation of Murcia (GERM 04543/07).



ISRN Urology ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
R. Nuñez-Calonge ◽  
S. Cortes ◽  
M. Gago ◽  
P. López ◽  
P. Caballero-Peregrin

Objective. To optimise the use of freeze/thaw testicular immotile spermatozoa from nonobstructive azoospermia patients and to analyse the outcome of intracytoplasmic sperm injection (ICSI) of such spermatozoa. Methods. Testicular specimens were retrieved and cryopreserved from forty patients with nonobstructive azoospermia and underwent one cycle with thawed spermatozoa (Group I) that led to pregnancy in sixteen cases. Twenty-four patients of group I underwent treatment with the same batch of thawed spermatozoa (Group II). For the first ICSI attempt, injection was performed when motile spermatozoa were found. In group II, injection was performed when maximum motility was reached. We compared mean of fertilization rate, embryo quality, clinical pregnancy rate and embryo implantation rate. Results. The mean percentage of motility was significantly higher in the group II than in the group I (18, 6 versus 8, 2). Group I showed a significant decrease in fertilization rates when compared with cryopreserved testicular spermatozoa in group II (54% versus 72%, ). No difference was noted between the cleavage rate, embryo quality, clinical pregnancy rates and implantation rates among group II and I. Conclusion. Fecundation rate can be significantly improved after in-vitro culture and sperm selection of frozen-thawed immotile testicular spermatozoa in patients with nonobstructive azoospermia.



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