Relationship between sperm mitochondrial membrane potential, sperm motility, and fertility potential.
OBJECTIVE
To analyze the relationship between sperm mitochondrial membrane potential and sperm motility parameters by means of a computer-assisted sperm analyzer (CASA) and in-vitro fertilization rate(%FR).


METHODS
Semen samples were obtained from 26 men undergoing in vitro fertilization-embryo transfer (IVF-ET). Informed consent was obtained from all men prior to the study. Samples were prepared using wash and swim-up method in HEPES-HTF medium. The sperm motility (%MOT), progressive motility (%PMOT), average path velocity (VAP) microm/s), straight line velocity (VSL) (micro m/s), curvilinear velocity (VCL) (microm/s) and %hyperactivated sperm (%HA), and the %FR were assessed. The samples were incubated in the presence of 2.0 mciromol/L of 5,5',6,6'-tetra-chloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) for 30 min at 37 degrees C in air and washed in PBS before flow cytometry (FACSCalibur: Becton Dickinson) analysis. The mitochondrial probe JC-1 was used to identify the mitochondrial membrane potential. The sperm was divided into three populations according to the fluorescence pattern as follows: the high mitochondrial membrane potential group (n=8), the moderate group (n=5), and the low group (n=13). Statistical analysis was performed using unpaired t-test.


RESULTS
Significant differences were found between the high and the low groups in %MOT (91.1+/-8.5 vs 63.0+/-32.7, mean+/-SD), VAP (73.0+/-14.2 vs 52.1+/-12.5), VCL (127.0+/-28.1 vs 87.0+/-22.6), %HA (27.3+/-23.6 vs 7.2+/-9.0) and %FR [73.2 (48/56) vs 59.0 (69/117)]. No significant differences were found in other CASA parameters.


CONCLUSIONS
When the sperm mitochondrial membrane potential increases, sperm motility parameters and fertility potential will also increase. The JC-1 dye method is useful to predict sperm fertility potential.
Kasai
Tsuyoshi
T
Department of Obstetrics and Gynecology, Yamanashi Medical University, Shimokato 1110, Tamaho, Nakakoma, Yamanashi 409-3898, Japan.
Ogawa
Keigo
K
Mizuno
Kaoruko
K
Nagai
Seiichiro
S
Uchida
Yuzo
Y
Ohta
Shouji
S
Fujie
Michiko
M
Suzuki
Kohta
K
Hirata
Shuji
S
Hoshi
Kazuhiko
K
D004624:Embryo Transfer; D005260:Female; D005298:Fertility / Q000502:physiology*; D005307:Fertilization in Vitro; D005434:Flow Cytometry; D006801:Humans; D007425:Intracellular Membranes / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000502:physiology*; D008928:Mitochondria / Q000502:physiology* / Q000648:ultrastructure; D012661:Semen / Q000502:physiology; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*