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Acta Physiologica 2012; Volume 206, Supplement 693
Joint FEPS and Spanish Physiological Society Scientific Congress 2012
9/8/2012-9/11/2012
Santiago de Compostela, Spain
INVESTIGATION OF ACIDOSIS DEFENSE MECHANISMS IN PREIMPLANTATION STAGES EMBRYOS IN MOUSE
Abstract number: P100
Erdogan1 S, Dagilgan1 S, Dundar-Yenilmez2 E, Tuli2 A, Urunsak3 I
1Physiology, Cukurova University Medical Faculty,
2Biochemistry, Cukurova University Medical Faculty,
3Gynecology and Obstetric, Cukurova University Medical Faculty
Objectives:
Intracellular pH (pHi) regulation is an important homeostatic function of cells. There are two pHi-regulatory mechanisms against acidosis: Exchangers of the Na+/H+ NHE) and Na+,HCO3-/Cl- (NDBCE). Although NHE activity high at GV-stage oocyte it has been inhibited during meiotic maturation. When oocyte reaches at pronuclear stage (PN) zygote, it recovers from this inhibition. On the other hand, we previously found that complementary regulation against to acidosis has been accomplished by NDCBE during meiotic maturation. Given that NHE activity is inhibited during this period, we investigated whether NHE and NDBCE activities change from PN zygote to blastocyst stage embryos in mice.
Materials:
PN zygotes, two-cell (2-c), four-cell (4-c), morula and blastocyst stage embryos were obtained by classical procedure from super ovulated female. pHi was recorded using an imaging system attached to epifluorescence microscope. Activities of NHE and NDBCE were determined functionally in absence or presence HCO3- in medium, respectively, by using recovery curve from acidosis. Amiloride and DIDS were used for inhibition of NHE and NDBCE activities, respectively. Differences between groups were determined by using one-way ANOVA, and statistical significance was accepted at p<0.05.
Results:
We found out that NHE activity was high all stage of embryos, but its activity at 2-c and morula stage embryos was insignificantly higher (in pHU/min; PN zygote 0,037±0,017; 2-c 0,084±0,021; 4-c, 0,036±0,012; morula, 0,068±0,013; blastocyst, 0,032±0,015). Also, NDBCE activity contributed acidosis recovery in all stage embryos, except morula. Besides, amiloride and DIDS significantly inhibited the activities of NHE and NDBCE, respectively.
Conclusions:
Effective acidosis defense mechanisms of preimplantation stage embryos showed that embryos constitute appropriate regulation in accordance with their metabolic end product (increased acidic load) and with acidic surroundings in uterine.
This study was supported by TUBITAK (111S156).
To cite this abstract, please use the following information:
Acta Physiologica 2012; Volume 206, Supplement 693 :P100