[Effects of controlled ovarian hyperstimulation on mitochondria copy number and functions in murine oocytes].
OBJECTIVE
To investigate the effect of whether controlled ovarian hyperstimulation (COH) on mitochondrial DNA (mtDNA) copy number, mitochondrial function, distribution, the level of reactive oxygen species (ROS) in oocytes and the mechanism of oocyte loss in COH.


METHODS
Matured murine oocytes were classified into COH group and natural cycles (NC) group. The copies of mtDNA, the magnitude of mitochondrial membrane potential (Δφm) and oocyte adenosine triphosphate (ATP) content, pattern of mitochondrial distribution, and ROS levels were evaluated by realtime PCR, immunofluorescence and fluorescence-luciferase mensuration.


RESULTS
The copies of mtDNA, the levels of Δφm, and ATP content in oocytes between COH and NC groups showed statistical difference [(1.15 ± 0.01)×10(5), 0.34 ± 0.03 and (241 ± 20) fmol/oocyte (COH)] versus [(2.15 ± 0.19)×10(5), 0.82 ± 0.07 and (325 ± 11) fmol/oocyte (NC)], respectively(P < 0.05). However, there were no significant differences in the rate of evenly distributed mitochondria and the level of ROS in oocytes from COH and NC [(76.5% (78/102) in COH versus 82.1% (69/84)]; 1.07 ± 0.07 in COH versus 0.93 ± 0.08 in NC (P > 0.05).


CONCLUSIONS
It was indicated that non-physiological COH treatments inhibit mtDNA replication, alter mitochondrial function, which might partly be involved in the low development potential of COH oocyte.
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China. Email:dafeng76@126.com.
Hong-shan
HS
Ge
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
Fan
F
Zhang
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
Xiao-he
XH
Li
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
Hua
H
Chen
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
Hai-tao
HT
Xi
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
Jian-ying
JY
Huang
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
Chun-fang
CF
Zhu
Reproductive Medical Center, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China.
Jie-qiang
JQ
Lü
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004272:DNA, Mitochondrial / Q000378:metabolism*; D005260:Female; D006064:Gonadotropins, Equine / Q000008:administration & dosage; D053078:Membrane Potential, Mitochondrial; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D054315:Oocyte Retrieval; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D010062:Ovulation Induction / Q000379:methods*; D018384:Oxidative Stress / Q000187:drug effects; D011897:Random Allocation; D017382:Reactive Oxygen Species / Q000378:metabolism
D004272:DNA, Mitochondrial; D006064:Gonadotropins, Equine; D017382:Reactive Oxygen Species; D000255:Adenosine Triphosphate