Amino acid metabolism of bovine blastocysts derived from parthenogenetically activated or in vitro fertilized oocytes

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.

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 675 ◽  
Author(s):  
Bo-Hyun Choi ◽  
Jonathan L. Coloff

Far beyond simply being 11 of the 20 amino acids needed for protein synthesis, non-essential amino acids play numerous important roles in tumor metabolism. These diverse functions include providing precursors for the biosynthesis of macromolecules, controlling redox status and antioxidant systems, and serving as substrates for post-translational and epigenetic modifications. This functional diversity has sparked great interest in targeting non-essential amino acid metabolism for cancer therapy and has motivated the development of several therapies that are either already used in the clinic or are currently in clinical trials. In this review, we will discuss the important roles that each of the 11 non-essential amino acids play in cancer, how their metabolic pathways are linked, and how researchers are working to overcome the unique challenges of targeting non-essential amino acid metabolism for cancer therapy.


2020 ◽  
Vol 26 (4) ◽  
pp. 277-287
Author(s):  
Christine Leary ◽  
Roger G Sturmey

Abstract The pattern of metabolism by early embryos in vitro has been linked to a range of phenotypes, including viability. However, the extent to which metabolic function of embryos is modified by specific methods used during ART has yet to be fully described. This study has sought to determine if the mode of fertilization used to create embryos affects subsequent embryo metabolism of substrates. A metabolic profile, including consumption of key substrates and the endogenous triglyceride content of individual IVF and ICSI supernumerary embryos, was assessed and compared. Embryo development and quality was also recorded. All embryos were donated at a single clinical IVF center, on Day 5, from 36 patients aged 18–38 years, The data revealed that consumption of glucose and pyruvate, and production of lactate, did not differ between embryos created by IVF or ICSI. Similarly, the mode of insemination did not impact on the triglyceride content of embryos. However, ICSI-derived embryos displayed a more active turnover of amino acids (P = 0.023), compared to IVF embryos. The specific amino acids produced in higher quantities from ICSI compared to IVF embryos were aspartate (P = 0.016), asparagine (P = 0.04), histidine (P = 0.021) and threonine (P = 0.009) while leucine consumption was significantly lower (P = 0.04). However, importantly neither individual nor collective differences in amino acid metabolism were apparent for sibling oocytes subjected to either mode of fertilization. Embryo morphology (the number of top grade embryos) and development (proportion reaching the blastocyst stage) were comparable in patients undergoing IVF and ICSI. In conclusion, the microinjection of spermatozoa into oocytes does not appear to have an impact on subsequent metabolism and viability. Observed differences in amino acid metabolism may be attributed to male factor infertility of the patients rather than the ICSI procedure per se.


2006 ◽  
Vol 400 (1) ◽  
Author(s):  
Susan M. Hutson

BCAAs (branched-chain amino acids) are indispensable (essential) amino acids that are required for body protein synthesis. Indispensable amino acids cannot be synthesized by the body and must be acquired from the diet. The BCAA leucine provides hormone-like signals to tissues such as skeletal muscle, indicating overall nutrient sufficiency. BCAA metabolism provides an important transport system to move nitrogen throughout the body for the synthesis of dispensable (non-essential) amino acids, including the neurotransmitter glutamate in the central nervous system. BCAA metabolism is tightly regulated to maintain levels high enough to support these important functions, but at the same time excesses are prevented via stimulation of irreversible disposal pathways. It is well known from inborn errors of BCAA metabolism that dysregulation of the BCAA catabolic pathways that leads to excess BCAAs and their α-keto acid metabolites results in neural dysfunction. In this issue of Biochemical Journal, Joshi and colleagues have disrupted the murine BDK (branched-chain α-keto acid dehydrogenase kinase) gene. This enzyme serves as the brake on BCAA catabolism. The impaired growth and neurological abnormalities observed in this animal show conclusively the importance of tight regulation of indispensable amino acid metabolism.


1990 ◽  
Vol 268 (3) ◽  
pp. 799-802 ◽  
Author(s):  
A E Tedstone ◽  
V Ilic ◽  
D H Williamson

Measurements of the tissue accumulation in vivo and in vitro by hepatocytes and mammary-gland acini of alpha-amino[1-14C]isobutyrate ([1-14C]AIB) were compared in virgin and lactating rats. The results indicate the existence of a reciprocal relationship between mammary gland and liver for AIB accumulation that is dependent on the lactational and the nutritional state of the rat. This suggests that amino acids are preferentially directed to the mammary gland during active lactation.


1996 ◽  
Vol 8 (5) ◽  
pp. 835 ◽  
Author(s):  
T Pinyopummintr ◽  
BD Bavister

Effects of amino acids on early bovine embryo development in vitro were examined using a chemically-defined, protein-free culture medium. Bovine embryos produced in vitro were cultured from 18 h to 72 h post insemination in a simple medium containing lactate as the only energy source except for the amino acid treatments. Subsequently, embryos were transferred to TCM-199 supplemented with serum for blastocyst development to substantiate their developmental competence. Treatments were: (1) non-essential amino acids from TCM-199 (NEA); (2) essential amino acids from TCM-199 (EA); (3) NEA+EA; (4) Eagle's minimum essential medium amino acids (MEM AA); (5) 11 amino acids present in HECM-6 (11 AA); and (6) 0.2 mM glutamine (GLN). A higher proportion of embryos (percentage of inseminated ova) cleaved to the > or = 8-cell stage by 72 h post insemination in NEA (56.7%), EA (41.2%), 11 AA (40.3%) and GLN (51.1%) than in either NEA+EA (30.0%) or MEM AA (33.1%). However, after transfer to complex medium, embryos that had developed in EA, as well as those in MEM AA or NEA+EA, produced significantly fewer blastocysts (37.1%, 34.4% and 25.6% respectively) than those in NEA (56.7%), GLN (48.9%) or 11 AA (37.7%). The ability of blastocysts to hatch from their zonae pellucidae was also affected by amino acid treatment during cleavage stages. The present study indicated that the addition of NEA or GLN or 11 AA to a chemically-defined culture medium during the cleavage phase of bovine embryo development increases their subsequent ability to reach the blastocyst stage. These data have implications for understanding the nutritional needs of bovine embryos produced in vitro and for optimizing the composition of culture media to support their development.


2016 ◽  
pp. 823-832 ◽  
Author(s):  
P. DRÁBKOVÁ ◽  
L. ANDRLOVÁ ◽  
R. HAMPL ◽  
R. KANĎÁR

The aim of this study was to find some relationship between amino acid metabolism and the embryo morphokinetic parameters studied via time-lapse analysis. Study included 48 human embryo samples and their culture media. Two groups of embryos were identified: embryos reached the 8-cell stage on day 3 (n=34) and embryos failed to develop at any point during the incubation (n=14). Amino acids levels were measured on day 3 of embryo development; using time-lapse analysis, the precise timing of embryo cleavage, synchrony of division, grade of fragmentation etc. were established. No statistically significant differences between dividing and arresting embryos were observed in terms of amino acids production/consumption and turnover. Amino acids which were part of the culture medium did not exhibit any statistically significant correlation with kinetic parameters with the exception of the grade of fragmentation on day 3; there were negative correlation with glutamate, and positive with glutamine, glycine and taurine. In some dividing and in some arresting embryos appeared new amino acids which strongly correlated with each other, with methionine, but not with any other amino acid that is a regular part of the culture medium.


Reproduction ◽  
2004 ◽  
Vol 127 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Nicolas M Orsi ◽  
Henry J Leese

The accumulation of ammonium is a major artefact ofin vitroembryo culture. This study has examined ammonium production and potential mechanisms of disposal in preimplantation bovine blastocysts. Embryos were produced byin vitromaturation and fertilisation of oocytes, and cultured in synthetic oviduct fluid containing amino acids and BSA (SOFaaBSA). Ammonium/urea concentrations were determined enzymatically. Amino acid appearance/disappearance ‘profiles’ of single blastocysts were determined at 0, 1.25 and 2.5 mM NH4Cl (with or without 0.33 mM pyruvate), and with or without 10 mM dipicolinic acid (DPCA; a glutamate dehydrogenase (GLDH) inhibitor) or 2 mM amino-oxyacetate (AOA; a transaminase inhibitor). Free ammonium was produced at a rate of 4.281 (±0.362) pmol/embryo/h, while urea production was undetectable. The presence/absence of pyruvate affected amino acid profiles, especially alanine appearance (P< 0.001), glutamate disappearance (P< 0.05) and overall turnover (the sum of appearance and disappearance) (P< 0.001). GLDH inhibition with DPCA had no effect on amino acid overall disappearance, but glutamate disappearance increased, while that of arginine decreased (P< 0.05). The transaminase inhibitor, AOA, depressed turnover (P< 0.05), aspartate and glutamate disappearance, and alanine appearance. Thus, bovine blastocysts release ammonium as free ions or fix them, not as urea, but as alanine, possibly glutamine and, less likely, arginine. An active role for GLDH and transaminases in regulating blastocyst amino acid metabolism was demonstrated.


1991 ◽  
Vol 276 (2) ◽  
pp. 559-561 ◽  
Author(s):  
M Parry-Billings ◽  
S J Bevan ◽  
E Opara ◽  
E A Newsholme

The effect of changes in cell volume on the rates of release of glutamine and alanine from muscle and on the concentrations of these amino acids in muscle were investigated by using an isolated preparation of rat skeletal muscle incubated in the presence of hypo- and hyper-osmotic media. Changes in cell volume were associated with changes in the rates of release of glutamine and alanine from muscle: incubation in hypo-osmotic medium decreased the rates of release of glutamine and alanine, and incubation in hyperosmotic medium increased these rates. These changes were rapidly reversed by a change in osmoticity of the medium. Despite marked changes in cell volume, the concentrations of these amino acids in muscle were maintained. It is suggested that cell volume may play a role in the regulation of amino acid metabolism in skeletal muscle.


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