RESUMEN
Objective: In conventional assisted reproductive technology [ART], oocytes are cultured in static microdrops within Petri dishes that contain vast amounts of media. However, the in vivo environment is dynamic. This study assesses in vitro oocyte maturation through the use of a new microfluidic device. We evaluate oocyte fertilization to the blastocyct stage and their glutathione [GSH] contents in each experimental group
Materials and Methods: In this experimental study, we established a dynamic culture condition. Immature oocytes were harvested from ovaries of Naval Medical Research Institute [NMRI] mice. Oocytes were randomly placed in static [passive] and dynamic [active] in vitro maturation [IVM] culture medium for 24 hours. In vitro matured oocytes underwent fertilization, after which we placed the pronucleus [PN] stage embryos in microdrops and followed their developmental stages to blastocyst formation after 3 days. GSH content of the in vitro matured oocytes was assessed by monochlorobimane [MCB] staining
Results: We observed significantly higher percentages of mature metaphase II oocytes [MII] in the passive and active dynamic culture systems [DCS] compared to the static group [P<0.01]. There were significantly less mean numbers of germinal vesicle [GV] and degenerated oocytes in the passive and active dynamic groups compared to the static group [P<0.01]. Fertilization and blastocyst formation rate in the dynamic systems were statistically significant compared to the static cultures [P<0.01]. There was significantly higher GSH content in dynamically matured oocytes compared to statically matured oocytes [P<0.01]
Conclusion: Dynamic culture for in vitro oocyte maturation improves their developmental competency in comparison with static culture conditions
RESUMEN
Neutrophil gelatinase-associated lipocalin [NGAL/Lcn2], comprise a group of small extracellular proteins with a common beta-sheet-dominated 3-dimensional structure. In the past, it was assumed that the predominant role of lipocalin was acting as transport proteins. Recently it has been found that oxidative stress induces Lcn2 expression. It has been also proved that electromagnetic field [EMF] produces reactive oxygen species [ROS] in different tissues. Expression of Lcn2 following exposure to electromagnetic field has been investigated in this study. Balb/c mice [8 weeks old] were exposed to 3 mT, 50 HZ EMF for 2 months, 4 hr/day. Afterwards, the mice were sacrificed by cervical dislocation and livers were removed. The liver specimens were stained with Haematoxylin-Eosin [H and E] and analyzed under an optical microscope. Total RNA was extracted from liver and reverse transcription was performed by SuperScript III reverse transcriptase with 1 micro g of total RNA. Assessment of Lcn2 expression was performed by semiquantitative and real time-PCR. The light microscopic studies revealed that the number of lymphocyte cells was increased compared to control and dilation of sinosoids was observed in the liver. Lcn2 was up-regulated in the mice exposed to EMF both in mRNA and protein levels. To the extent of our knowledge, this is the first report dealing with up-regulation of Lcn2 in liver after exposure to EMF. The up-regulation might be a compensatory response that involves cell defense pathways and protective effects against ROS. However, further and complementary studies are required in this regards