Effect of Modification of Ovary Preservation Solution by Adding Glucose on the Maturation and Development of Pig Oocytes after Prolonged Storage

Abstract

Abstract. Oocytes lose their developmental competence during prolonged storage of the ovary. In the present study, we supplemented the preservation solution for pig ovaries (phosphate buffered saline, PBS) with glucose and preserved the ovaries for 6 h at 25 C. Subsequently, we examined the glucose concentration of the follicular fluid (FF), pH of the FF, survival rate of the granulosa cells, and maturation and developmental competence of oocytes after storage. During storage, the glucose concentration of the FF (2.1 mM), pH of the FF (7.4), and survival rate of the granulosa cells (69.5%) rapidly decreased (glucose concentration: under 1.1 mM; pH: 6.8; and survival rate: 43%). On the other hand, when the preservation solution was supplemented with glucose (15 mM), the glucose concentration of the FF increased and the survival rate of the granulosa cells improved, although the pH of the FF decreased further (from 6.8 to 6.6). In addition, supplementation with glucose significantly improved the rates of oocytes at metaphase II (0 h: 65.0%; 6 h without glucose: 23.8%; and 6 h with glucose: 43.8%) and attenuated the decline in the rates of fertilization and development that resulted from prolonged storage, although there were no significant differences. In conclusion, modification of the preservation solution by the addition of glucose increased the glucose concentration of the FF and improved the rate of maturation of pig oocytes. Key words: Ovary preservation, Glucose, Pig oocyte (J. Reprod. Dev. 52: [669][670][671][672][673][674] 2006) ocyte quality is a major factor that affects the developmental rate of in vitro matured/in vitro fertilized oocytes to the blastocyst stage. For in vitro embryo production in domestic animals, oocytes are generally aspirated from ovaries collected at a slaughterhouse. These ovaries are preserved in physiological saline or phosphate buffered saline (PBS) at 30-35 C for a predetermined time period b e f o r e o o c y t e c o l l e c t i o n . D u r i n g o v a r y preservation, the supply of oxygen and blood flow to the ovaries is halted; thus, the oocytes are maintained under ischemic conditions. During bovine ovary preservation, a decrease in both the glucose concentration of the folliclular fluid (FF) and the survival rate of the granulosa cells in the follicle and an increase in the potassium ion (K + ) concentration of the FF indicate that the oocyte and surrounding cells are exposed to suboptimal conditions compared with the in vivo conditions [1,2]. In general, to prevent ischemic injuries, a delicate balance of the energy levels within the ovary during storage is thought to be achieved by two strategies, (1) reducing the activity of energyconsuming processes, and (2) increasing the rate of energy production (via glycolysis). Lowering the

The Effect of Ovary Storage and In Vitro Maturation on mRNA Levels in Bovine Oocytes; A Possible Impact of Maternal ATP1A1 on Blastocyst Development in Slaughterhouse-derived Oocytes

“…Oxidative stress caused by atmospheric tensions of O 2 also exerts various effects on animal cells including alterations in metabolic processes at the molecular level [30]. Furthermore, previous reports have revealed the severe reduction of glucose concentration in follicle fluid during ovary storage, which was associated with decreased oocyte developmental competence [31,32]. In fact, removal and storage prevent blood flow and thus energy supplies in organs, and therefore, maintaining normal ATP levels in tissues is considered to have basic importance for organ preservation [33].…”

Influência Dos Meios De Estocagem Durante O Transporte De Ovários Bovinos a 4°c Sobre a Recuperação E Qualidade Oocitária

“…Além disso, os componentes do SFB combinados com o PBS podem ter permitido que uma maior quantidade de células do cumulus permanecesse viva após as 24 h de resfriamento, uma vez que baixas temperaturas, em um meio que oferece um bom aporte nutricional, impede que a membrana das células se desintegre (LIN et al, 2011). Em soma, anteriormente também foi relatado o uso de suplementação energética em PBS para o armazenamento de ovários bovinos (IWATA et al, 2005; adição de rafinose) e suínos (SAKAMOTO et al, 2006; adição de glicose) onde se observou uma melhora na competência oocitária. Já em ovinos, a suplementação do PBS para o armazenamento (24 h a 4ºC) dos ovários com melatonina, um composto antioxidante, permitiu a maturação e o desenvolvimento embrionário superior ao controle sem antioxidante (GOODARZI et al, 2017).…”

Tingkat Fertilisasi Oosit Domba Dari Ovarium Yang Disimpan Pada Suhu Dan Waktu Yang Berbeda Secara in Vitro

“…Menurut Wang et al (2009), sitoplasma dan nukleus rentan terhadap cekaman panas maupun dingin. Penyimpanan ovarium in vitro dapat menyebabkan disorganisasi dari mikrotubulus, kerusakan kromosom, akumulasi metabolit, kenaikan indeks apoptosis sel granulosa, dan perubahan struktur membran cytoplastic (Pedersen et al, 2004;Wongsrikeao et al, 2005;Sakamoto et al, 2006).…”