Metabolism of pyruvate by pre-elongation sheep embryos and effect of pyruvate and lactate concentrations during culture in vitro

1993 ◽  
Vol 5 (4) ◽  
pp. 417 ◽  
Author(s):  
JG Thompson ◽  
AC Bell ◽  
PA Pugh ◽  
HR Tervit

In the first of two experiments, utilization of [1-14C]pyruvate by 8-cell and blastocyst-stage embryos derived in vivo was examined during a 3-h incubation in HEPES-buffered synthetic oviduct fluid (SOF) medium in the presence or absence of other substrates. In the second, a factorial design examined the effect of pyruvate (0, 0.33, 1.0 and 3.3 mM) and lactate (3.3, 10 and 33 mM) on development of 1- and 2-cell sheep embryos cultured in vitro in a modified SOF medium (containing glucose, glutamine and modified Eagle's medium non-essential amino acids). Peak utilization of [1-14C]pyruvate was unaffected by the presence or absence of other energy substrates. In contrast, rate of utilization was affected by the addition of other energy substrates, with half maximal utilization occurring at either 0.4 +/- 0.2 mM or 1.2 +/- 0.2 mM for 8-cells and either 0.2 +/- 0.2 mM or 1.3 +/- 0.3 mM for blastocysts when incubated in the absence or presence of other energy substrates respectively. In the second experiment the proportion of embryos developing to blastocysts was inhibited by high lactate levels (P < 0.001), but was generally not affected by pyruvate concentration. However, there was a significant interaction (P < 0.001) between pyruvate and lactate when both were present in the medium. At 0.33 mM pyruvate, 3.3 mM lactate supported good development (83 +/- 8% blastocysts) whereas 10 mM lactate supported less development (50 +/- 11%). However, at the higher levels of pyruvate this effect was lost.(ABSTRACT TRUNCATED AT 250 WORDS)

1998 ◽  
Vol 10 (3) ◽  
pp. 279 ◽  
Author(s):  
Y. G. Jung ◽  
T. Sakata ◽  
E. S. Lee ◽  
Y. Fukui

The uptake and synthesis of 19 amino acids by fresh or frozen–thawed bovine blastocysts produced by parthenogenesis (PT) or in vitro fertilization (IVF) were compared in the present study. Fresh blastocysts, 180 h after IVF or PT activation, and frozen–thawed blastocysts, 168 h old and cultured for 12 h post-thawing, were cultured in synthetic oviduct fluid medium (SOFM) containing polyvinyl alcohol (PVA) with both essential and non-essential amino acids (EAA and NEAA, respectively) (Medium 1: M1) or SOFM containing PVA with only EAA (Medium 2: M2). In Experiment 1, when fresh or frozen–thawed PT blastocysts were cultured in M1, the uptake of glutamate (in fresh only), aspartate and arginine, and the synthesis of glutamine and alanine were significantly enhanced. In the culture with M2, serine, asparagine, glutamate, glutamine, glycine, arginine and alanine were significantly taken up. It was found that the glutamine concentrations was significantly higher (P < 0.001) in the culture medium drops containing embryos than in the drops without embryos. In Experiment 2, when PT blastocysts were cultured in M1, the uptake of aspartate and synthesis of alanine were greater (P < 0.01) than those by IVF blastocysts. When M2 was used, a significant (P < 0.01) production of serine, asparagine, glutamate, glutamine and alanine, and the uptake of arginine by PT blastocysts were observed. In Experiment 3, when IVF blastocysts were cultured in M1, fresh blastocysts depleted more aspartate and glutamate, and produced more glutamine and alanine than frozen–thawed blastocysts. When cultured in M2, frozen–thawed blastocysts depleted more threonine (P < 0.01) than fresh blastocysts. These results indicate that the uptake and synthesis of amino acids were different in fresh or frozen–thawed bovine blastocysts derived from PT or IVF. These differences in amino acid metabolism may be related to the viability of the blastocysts.


2010 ◽  
Vol 22 (1) ◽  
pp. 231
Author(s):  
J. Block ◽  
L. Bonilla ◽  
P. J. Hansen

The objective of the present study was to determine whether culture of bovine embryos in a proprietary serum-free culture medium, Block-Bonilla-Hansen-7 (BBH-7), could improve development to the blastocyst stage and enhance survival following vitrification. For Exp. 1, embryos were produced in vitro and cultured in BBH-7 or modified synthetic oviductal fluid (mSOF; as in zygote 10:341 except with 10 μL mL-1 of nonessential amino acids, 20 μL mL-1 of essential amino acids, and 1 mg mL-1 of polyvinyl alcohol instead of albumin) in 5% (v/v) oxygen. Grade 1 expanded blastocysts were harvested at Day 7 post-insemination and vitrified using the open-pulled straw method (Vagta et al. 1998 Mol. Reprod. Dev. 51, 53-58). Vitrified embryos were thawed and cultured in vitro in either mSOF or BBH-7 supplemented with 10% fetal bovine serum and 50 μM dithiolthreitol. Re-expansion and hatching rates were recorded at 24, 48, and 72 h post-thaw. There was no effect of culture medium on cleavage rate. The proportion of oocytes that developed to the blastocyst and advanced blastocyst stages (expanded, hatching, and hatched) at Day 7 was higher (P < 0.001) for embryos cultured in BBH-7 than for embryos cultured in mSOF (41.9 ± 2.0 v. 14.7 ± 2.0% and 31.1 ± 1.3 v. 6.4 ± 1.3%, respectively). There was no effect of culture medium on re-expansion rates at 24, 48, and 72 h post-thaw or on hatching rates at 48 or 72 h. However, the proportion of embryos that were hatching or had hatched by 24 h post-thaw was higher (P < 0.001) for BBH-7 than for mSOF (59.0 ± 0.5 v. 26.7 ± 0.5%). For Exp. 2, late lactation and/or repeat breeder, lactating Holstein cows were synchronized for timed embryo transfer using the OvSynch-56 protocol. Embryos were produced in vitro and cultured in BBH-7 in 5% (v/v) oxygen. Vitrified embryos were produced as for Exp. 1. Fresh embryos were grade 1 expanded blastocysts harvested at Day 7 after insemination. A single embryo was transferred at Day 7 after putative ovulation to all cows with a corpus luteum confirmed by ultrasonography. Pregnancy was diagnosed at Day 28-30 of gestation by ultrasonography. There was no difference in the proportion of recipients that became pregnant after receiving either a fresh (7/18 = 39%) or vitrified (10/27 = 37%) embryo cultured in BBH-7. The results of the present study indicate that BBH-7 can be used to increase the proportion of oocytes that develop to the blastocyst stage. Moreover, the results demonstrate that vitrified embryos produced after culture in BBH-7 can achieve pregnancy rates similar to those obtained using fresh embryos. Support: USDA 2006-55203-17390 and Southeast Milk Checkoff Program.


2018 ◽  
Vol 30 (1) ◽  
pp. 189
Author(s):  
L. Landeo ◽  
R. S. Molina ◽  
M. E. Zuñiga ◽  
T. R. Gastelu ◽  
C. Sotacuro ◽  
...  

The objective of this study was to evaluate the in vitro developmental competence of alpaca embryos bisected at different embryonic stages. Gametes were obtained from ovaries and testes collected from a local abattoir. Cumulus-oocyte complexes (COC) were recovered (n = 120) by aspiration of ovarian follicles using a 5-mL syringe with an 18-gauge needle. Then, COC with at least 3 layers of cumulus cells and a homogeneous cytoplasm were matured in TCM-199 supplemented with 10% FCS, FSH (0.02 IU [JM1] [P2] [P3]), and 0.01 mg mL−1 oestradiol 17β [JM4] for 26 h at 38.5°C and 5% CO2 in air. After in vitro maturation, COC were placed in a 30-mL Petri dish containing FERT-TALP solution for 30 min. Then, epididymal alpaca spermatozoa (3 × 106 mL−1) were added to the dish and co-incubated with the COC for 20 h at 38.5°C and 5% CO2 in air. Motile epididymal sperm were selected by swim-up method centrifuged for 15 min at 350 × g in 2 mL of SPERM-TALP supplemented with 6 mg mL−1 of fatty-acid-free BSA. Sperm pellet was extended and culture in 5% CO2 in air at 38.5°C for 45 min. Thirty-three viable embryos at different stages [2-cells (n = 6), 8-cells (n = 15), and morulae (n = 12)] were bisected into approximately equal halves using a micro-surgical blade. The embryos were previously treated with 2 mg mL−1 of protease from Streptomyces griseus (P 8811, Sigma, St. Louis, MO, USA) for 2 min to remove the zona pellucida. After bisection, the demi-embryos were cultivated in in vitro culture (IVC) medium containing 0.036 mg mL−1 sodium pyruvate, 0.146 mg mL−1 l-glutamine, 1% essential amino acids, 0.5% nonessential amino acids, and supplemented with 10% FCS using the well-of-the-well system. The demi-embryos were incubated for 7 days (changing the media every 48 h) in 5% CO2 in air at 38.5°C. Additional embryos (n = 60) were obtained using the same conditions described above and used as a control group (unmanipulated). We obtained 66 demi-embryos [2-cells (n = 12), 8-cells (n = 30), and morulae (n = 24)] after bisection that were considered for IVC. From 12 demi-embryos bisected at 2-cell and 30 bisected at 8-cell stages, 3 (25%) and 30 (100%) reached the morula stage respectively. However, they did not develop any further. Interestingly, 18 demi-embryos bisected in morula reached the blastocyst stage (80%). For unmanipulated embryos, we obtained 42% (25/60), 35% (21/60), 32% (19/60), and 28% (17/60) of cleavage, morulae, and blastocyst and hatched blastocyst rates, respectively. In conclusion, alpaca embryos bisected at earlier stages (less than 8-cell) are not suitable to produce blastocysts. The earliest stage to produce blastocyst from bisected alpaca embryos is the morula stage.


1970 ◽  
Vol 47 (3) ◽  
pp. 347-356 ◽  
Author(s):  
R. D. G. MILNER

SUMMARY Pieces of rabbit pancreas were incubated in vitro in an incubation medium containing no glucose or 1·5 mg. glucose/ml. In each of these conditions the effect on insulin release of each of the essential amino acids at 5 mm concentration was studied. Leucine was the only essential amino acid that stimulated insulin release to a level which reached statistical significance in an incubation medium containing no glucose. In medium containing 1·5 mg. glucose/ml., arginine, isoleucine, leucine and lysine stimulated insulin release and phenylalanine inhibited insulin release. Glucagon, theophylline or dibutyryl cyclic adenosine monophosphate stimulated insulin release significantly in the presence of leucine but not in the presence of arginine. Arginine stimulated insulin release in the presence of leucine. The results of these experiments characterize further the difference in the mechanism of action of leucine and arginine on the pancreatic β-cell and indicate possible explanations for results obtained in other species in vivo.


The cerebral influx rates of fifteen amino acids were measured directly in living rats by means of a new technique which makes it possible to maintain a constant specific activity of a radioactively labelled amino acid in the bloodstream. A wide variation in the influx rates of the amino acids was found. These rates differed from those found by other workers using in vitro preparations, but are consistent with the theory that amino acids enter the brain mainly by carrier mediated transport processes with a high degree of specificity. There are a number of important differences between the behaviour of the transport processes in vivo and in vitro . The influx rates of the various amino acids were directly proportional to their concentra­tions in blood plasma (over the range of concentrations studied). All the nutritionally essential amino acids had relatively high influx rates as did other amino acids which the brain does not seem to be able to synthesize. On the other hand, amino acids that the brain can readily synthesize and two amino acids which are not normally found in mammalian tissues had low influx rates.


1999 ◽  
Vol 11 (2) ◽  
pp. 127 ◽  
Author(s):  
J. M. Lim ◽  
B. C. Lee ◽  
E. S. Lee ◽  
H. M. Chung ◽  
J. J. Ko ◽  
...  

This study was conducted to examine the effects of carbohydrates and amino acids on the maturation and fertilization of bovine oocytes. To evaluate the effect of each treatment without any unpredictable interference, oocytes were cultured in a simply defined medium (modified Tyrode’s medium; mT) without the addition of hormones and proteins. In Experiment 1, oocyte maturation to the metaphase-II stage was significantly (P<0.0001) enhanced after the addition of glucose (5.6 mМ), lactate (10 mМ) and/or pyruvate (0.5 mМ) to mT (37–74%) than after no addition (0%). In mT supplemented with glucose, the addition of 19 essential and non-essential amino acids (aa; 0, 0.01, 0.1, 1, 5 or 10%) did not further improve in vitro maturation (Experiment 2) or in vitro fertilization (Experiment 3) of oocytes. However, more (P<0.05) pronuclear formation after in vitro-insemination was found in oocytes matured in mT with 1% aa and glucose than in oocytes matured in mT with glucose alone (56% vs. 35%). Penetration of spermatozoa into the ooplasm was initiated at 3 h after insemination and pronuclear formation from 8 h (Experiment 4). When cultured inseminated oocytes were examined up to 192 h post insemination, a significant (P<0.05) increase in the number of 2-cell (18 v. 38%) and 8-cell embryos, (7 v. 20%) and morulae (0 v. 8%) was found after the addition of 1% aa to mT with glucose than after no addition (Experiment 5). A limited number of oocytes matured in mT with aa and glucose developed to the blastocyst stage (6%). These results indicate that exogenous carbohydrates and amino acids are prerequisites for the maturation and fertilization of bovine oocytes in vitro. Glucose alone promotes the nuclear maturation of oocytes, whereas amino acids aid the pronuclear formation of fertilized oocytes.


Reproduction ◽  
2011 ◽  
Vol 141 (5) ◽  
pp. 685-695 ◽  
Author(s):  
Anna E Groebner ◽  
Isabel Rubio-Aliaga ◽  
Katy Schulke ◽  
Horst D Reichenbach ◽  
Hannelore Daniel ◽  
...  

Amino acids (AAs) are crucial for the developing conceptus prior to implantation. To provide insights into the requirements of the bovine embryo, we determined the AA composition of the uterine fluid. At days 12, 15, and 18 post-estrus, the uteri of synchronized pregnant and non-pregnant Simmental heifers were flushed for the analysis of 41 AAs and their derivatives by liquid chromatography–tandem mass spectrometry. The ipsilateral endometrium was sampled for quantitative PCR. In addition to a pregnancy-dependent increase of the essential AAs (P<0.01), we detected elevated concentrations for most non-essential proteinogenic AAs. Histidine (His) and the expression of the His/peptide transporter solute carrier 15A3 (SLC15A3) were significantly increased at day 18 of pregnancyin vivo. In addition,SLC15A3was predominantly stimulated by trophoblast-derived interferon-τ in stroma cells of anin vitroco-culture model of endometrial cells. Our results show an increased concentration of AAs most likely to optimally provide the elongating pre-attachment conceptus with nutrients.


2017 ◽  
Author(s):  
Yi Hu ◽  
Jon G. Sanders ◽  
Piotr Łukasik ◽  
Catherine L. D’Amelio ◽  
John S. Millar ◽  
...  

AbstractNitrogen acquisition is a major challenge for herbivorous animals, and the repeated origins of herbivory across the ants have raised expectations that nutritional symbionts have shaped their diversification. Direct evidence for N-provisioning by internally housed symbionts is rare in animals; among the ants, it has been documented for just one lineage. In this study we dissect functional contributions by bacteria from a conserved, multi-partite gut symbiosis in herbivorous Cephalotes ants through in vivo experiments, (meta)genomics, and in vitro assays. Gut bacteria recycle urea, and likely uric acid, using recycled N to synthesize essential amino acids that are acquired by hosts in substantial quantities. Specialized core symbionts of 17 studied Cephalotes species encode the pathways directing these activities, and several recycle N in vitro. These findings point to a highly efficient N-economy, and a nutritional mutualism preserved for millions of years through the derived behaviors and gut anatomy of Cephalotes ants.CategoryBiological Sciences-Evolution


1996 ◽  
Vol 8 (6) ◽  
pp. 945 ◽  
Author(s):  
RJ Partridge ◽  
HJ Leese

Bovine embryos produced in vitro from the putative zygote stage to the blastocyst stage, and blastocysts freshly flushed from the uterus, were cultured in a physiological mixture of amino acids. Depletion of amino acids from the medium and, in a few cases, their appearance, was measured by high performance liquid chromatography. Amino acids were depleted at widely differing rates. The depletion of amino acids was higher when embryos at later developmental stages were cultured, implying an increase in amino acid requirement with development. Threonine was the only amino acid to be depleted at all stages of development; depletion increased from 0.18 +/- 0.07 pmol embryo-1 h-1 at the putative zygote stage to 1.96 +/- 0.49 pmol embryo-1 h-1 at the blastocyst stage. Glutamine was depleted at the putative zygote stage and the 4-cell stage (0.76 +/- 0.05 and 0.94 +/- 0.10 pmol embryo-1 h-1 respectively), but was not significantly depleted at the later stages. Alanine was the only amino acid that appeared consistently in the medium and its production increased progressively throughout development. Aspartate, glutamate, threonine and lysine were depleted significantly by blastocysts derived both in vitro and in vivo; the embryos in vivo also depleted arginine, phenylalanine, isoleucine and tyrosine. These results indicate that individual amino acids are depleted at different rates by bovine preimplantation embryos and suggest that amino acid requirements change during development.


2016 ◽  
Vol 28 (2) ◽  
pp. 171
Author(s):  
B. R. Redel ◽  
L. D. Spate ◽  
B. Elliott ◽  
M. Paczkowski ◽  
R. L. Krisher ◽  
...  

Porcine embryo culture systems are suboptimal to the in vivo environment, and significant effort has been made to improve development to the blastocyst stage in vitro. Since metabolism of the early embryo has many similarities to the Warburg effect, our goal was to determine the role of glucose on development, gene expression, and metabolism of other energy substrates in the blastocyst stage embryo. Pig embryos were in vitro produced and cultured in MU1 containing pyruvate, lactate, amino acids, and either 0, 7.5, 15, or 250 µM glucose, N = 1164, 4 replications. There was no difference in blastocyst percentage between the 0 µM and 7.5 µM glucose (34% ± 6.5 v. 29% ± 8.2), but there was a decrease in development in response to 15 and 250 µM compared with 0 µM glucose (25% ± 8.5, 23% ± 8.7 v. 34% ± 6.5; P ≤ 0.01). Glucose transporters (SLC2A1 and SLC2A2) and hexokinases (HK1 and HK2) were analysed by qPCR to detect differences in gene expression, 3 replicates containing 10 blastocyst pools. The abundance of both HK1 and HK2 was decreased in blastocysts cultured with 7.5 µM glucose compared with 0 µM (P ≤ 0.04). Glucose transporters were not affected by glucose supplementation (P ≥ 0.5). Metabolic data were collected to determine if embryos were adjusting their energy substrate use in response to glucose. Two assays were completed to determine lactate and pyruvate consumption or release into the media by embryos, in comparison with media without embryos. In vitro-produced embryos were cultured in MU1 with 0 or 7.5 µM glucose N = 360, 4 replications. Both treatments consumed lactate, but there were no differences between treatments (6.8 ± 9.4 pmol/blastocyst/h v. 12.5 ± 1.6 pmol/blastocyst/h; P = 0.6). Blastocysts cultured in 7.5 µM glucose consumed pyruvate, whereas blastocysts without glucose produced pyruvate (–0.34 ± 0.3 pmol/blastocyst/h v. 0.73 ± 0.2 pmol/blastocyst/h; P < 0.01). It has been suggested that fructose is a more efficient replacement for glucose in pig embryo culture. Therefore, we produced pig embryos in vitro and cultured these embryos in MU1, MU1 + 2 mM glucose, or MU1 + 2 mM fructose to the blastocyst stage, 4 replications, N = 389. Again, there was a decrease in embryos that developed to the blastocyst stage in 2 mM glucose compared with MU1 control blastocysts (26% ± 5.8 v. 11% ± 2.5; P = 0.001), but there was only a trend for a decrease in development in response to 2 mM fructose (17 ± 2.3%; P = 0.06). There was no difference in total cell number between MU1, 2 mM glucose, and 2 mM fructose (30.6 ± 2.2, 30.5 ± 3.7, and 32.6 ± 3.0, respectively; P ≥ 0.9) 3 replications, N = 32. Because there is very little consumption of lactate and very low levels of pyruvate are being consumed when glucose is present, it does not appear that any of these energy substrates are major players for the developing pig embryo. Future experiments should be conducted to determine other means of energy production and metabolism in these embryos. The research was funded by Food for the 21st Century.


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