1,721,006 research outputs found
EFFETTI DELLA COLTURA DI MATURAZIONE IN VITRO (IVM) SUI LIVELLI INTRACELLULARI DELLE SPECIE REATTIVE DELL’OSSIGENO (ROS) IN OVOCITI EQUINI. EFFECTS OF IN VITRO MATURATION (IVM) CULTURE ON INTRACELLULAR REACTIVE OXYGEN SPECIES (ROS) LEVELS IN EQUINE OOCYTES
No full textMitochondria and reactive oxygen species distribution pattern in human oocytes: correlation with assisted reproductive technologies (ART) outcome
No full textMitochondrial distribution and activity in human mature oocytes: GnRH agonist vs antagonist for pituitary downregulation
No full textObjective: To analyze the effects of GnRH agonists versus antagonists on mitochondrial distribution and activity
in human mature oocytes.
Design: Randomized research experimental study.
Setting: Academic basic research laboratory and hospital-based fertility center.
Patient(s): Two hundred twenty-five supernumerary mature oocytes from 44 patients.
Intervention(s): Fluorescent staining and confocal laser scanning microscopy on oocytes after the use of either
GnRH agonist (group A) or GnRH antagonist (group B).
Main Outcome Measure(s): Oocyte mitochondrial distribution pattern and activity using MitoTracker Orange
CMTM Ros.
Result(s): More oocytes showing polarized mitochondrial distribution pattern were found in group A than in
group B (35% vs. 14%). In group B, hCG rather than GnRH agonist, for ovulation induction, resulted in more
oocytes showing heterogeneous (57% vs. 14%), in particular polarized (24% vs. 0) mitochondrial distribution.
In groups A and B, fluorescence intensity did not vary according to mitochondrial distribution pattern. However,
fluorescence intensity was higher in oocytes with polarized and large granules configurations in group B compared
to group A.
Conclusion(s): The GnRH agonist and antagonist may have different effects on oocyte mitochondrial distribution
pattern and activity. The GnRH antagonist may induce mitochondrial hyperactivity, which may be detrimental to
the oocyte. (Fertil Steril 2009;91:249–55. 2009 by American Society for Reproductive Medicine.
Distribution of active mitochondria in canine oocytes is related to reproductive cycle stage but can be damaged during IVM culture
No full textAim We investigated the effect of the reproductive cycle stage on the distribution of active mitochondria in canine oocytes examined 1) at collection and 2) after in vitro maturation (IVM).
Methods Cumulus-oocyte complexes (ooplasmic size >120 μm in diameter) were recovered from 20 bitches divided into five groups based on their reproductive status: anestrous (A, n=4), follicular phase (F, n=4), ovulation (O, n=2), early luteal phase (until 15 days after ovulation, EL, n=7) and mid/late luteal phase (MLL, n=3). IVM culture was performed in TCM199 with 10% estrous canine serum (72h, 5% CO2). Oocyte mitochondrial (mt) distribution pattern was revealed after 30’ incubation in 280 nM MitoTracker Orange CMTM Ros and confocal laser scanning microscopy. Data were analyzed by Chi-square Test.
Results In oocytes examined at collection, three mt patters were found: I) small granules diffused throughout the cytoplasm; II) diffused tubular networks; III) pericortical tubular networks. Significantly higher rates of oocytes showing heterogeneous mt patterns (II and III) were obtained from bitches in F (21/28, 75%) and in O (23/24, 96%) compared with bitches in A (4/13, 31%; F vs A: P<0.05; O vs A: P<0.001), in EL (27/44, 61%; F vs EL: NS; O vs EL: P<0.01), or in MLL (0/9, 0%; F vs MLL: P<0.05; O vs MLL: P<0.001).
In cultured oocytes, the maturation rates (MII+PB) did not differ statistically among reproductive stages (1%, 1/72 vs 6%, 12/189 vs 2% 1/58 vs 4% 2/47 vs 9%, 5/53, for oocytes from bitches in A, F, O, EL and MLL, respectively). The only oocyte from an A bitch had reticular mt pattern. The 12 oocytes from bitches in F showed tubular networks (3/12, 25%) or granular mt distribution (9/12, 75%). The only oocyte from an O bitch and all oocytes from bitches in EL (n=2 oocytes) and from bitches in MLL (n=5 oocytes) showed granular mt distribution.
Conclusions Our data demonstrate that the distribution of active mt in canine immature oocytes is related to cycle stage. However, the used IVM culture system did not yield high MII rates as well as mt distribution patterns expressive of full cytoplasmic maturation. This compromised oocyte energy status may be one of the factors responsible for overall reported low MII rates in this species
Analisi della distribuzione mitocondriale in ovociti di cagna esaminati al prelievo e dopo maturazione in vitro
No full textAttività dell’antagonista degli oppioidi naloxone sulla maturazione in vitro di ovociti di cagna: effetto enhancer nella fase anestrale. Atti SIRA, VI:99-102
No full textDistribuzione mitocondriale in ovociti umani in relazione al regime di stimolazione ovarica controllata. Mitocondrial distribution in human oocytes in relation to ovarian stimulation protocol. P. 147-149
No full textATP content and SOD activity in single oocytes before and after in vitro maturation
No full textThe developmental competence of in vitro-produced embryos is strictly related to oocyte quality. Analyses of energy and redox status parameters are emerging technologies useful for further oocyte quality characterisation. Mitochondrial (mt) activity is a necessary feature involved in cytoplasmic maturation, and the primary function of mitochondria is adenosine triphosphate (ATP) production. Mitochondria distribution pattern and ATP content are important parameters in the evaluation of oocyte metabolic activity, particularly activities driving microtubules dynamics leading to chromosomes segregation. Superoxide dismutase (SOD), a first-line antioxidant enzyme, has also been hypothesised as being associated to oocyte quality. The aim of the present study was to analyse ATP content and SOD activity in single equine oocytes examined before and after in vitro
maturation. Cumulus–oocyte complexes surrounded by a compact cumulus oophorus were recovered from the ovaries of slaughtered mares and analysed before or after in vitro maturation (Ambruosi et al. 2009 Theriogenology 71, 1093–1104). After cumulus cell removal, all oocytes underwent evaluation of signs of meiotic maturation, and only those oocytes showing cumulus expansion, regular ooplasmic size (4160 mm in diameter) and morphology, and 1st polar body extrusion were selected for analysis. Adenosine triphosphate intracellular levels were analysed by luciferin-luciferase bioluminescent reaction (ATPlite, PerkinElmer, Monza, Italy). Quantification of SOD activity was performed by spectro- photometrical assay with WST1 and by polyacrylamide native gel and nitro blue tetrazolium reduction method. Intracellular ATP levels were influenced by meiotic stage in that oocytes at the germinal vesicle stage (GV, n 1⁄4 15) showed 1.25 ` 0.8 pmol cell1, whereas metaphase II (MII) oocytes (n1⁄415) showed significantly higher levels (2.29`1.69 pmolcell1; Po0.05). This is in line with our previous observations on mt distribution pattern analysed by Mitotracker Orange CMTM Ros staining and confocal microscopy (Ambruosi et al. 2009). In vitro-matured MII oocytes showed significantly higher rates of perinuclear mt distribution pattern, indicating mt aggregation around meiotic metaphase spindle, compared with GV oocytes (3/12, 25% v. 0/13, 0% in GV oocytes; Po0.05). Superoxide dismutase spectrophotometrical activity was 0.72 ` 0.55 U mg1 prot in GV oocytes (n 1⁄4 4) and 2.33 ` 0.33 U mg1 prot in MII oocytes (n 1⁄4 2; P o 0.001). In native gel SOD activity was 16 285.05 arbitrary densitometric units (ADU) in a GV oocyte and 22 501.35 ADU in a MII oocyte. To our knowledge, this is the first study reporting intracellular SOD activity in single oocytes in mammals. Moreover, this is the first study reporting ATP content in single equine oocytes. Observed quantitative differences seem to be related to meiotic stage
Mitochondrial distribution and activity in canine oocytes is related to reproductive cycle stage but can be compromised during in vitro maturation
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