Mitochondrial distribution and activity in human mature oocytes: gonadotropin-releasing hormone agonist versus antagonist for pituitary down-regulation

Abstract

Objective: 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.