A Study On The Correlation Between Mitochondrial Function And Sperm Motility

PartⅠCorrelation of mRNA expressions of mitochondrial cytochrome oxidase subunitⅠ,Ⅱwith sperm motilityObjective: To compare mRNA expressions of mitochondrial cytochrome oxidaseⅠ(COXⅠ) andⅡ(COXⅡ) in ejaculated spermatozoa between healthy volunteers and infertile males with asthenospermia, in order to explore the correlation of mRNA expressions of COXⅠand COXⅡwith sperm motility and density. Methods: After routine examination, 26 healthy volunteers (sperm density≥20×106 /ml, a≥25% or a + b≥50% ) and 26 infertile males with asthenospermia (sperm density≥20×106 /ml, a<25% and a+b≤40%) were classified as control group and asthenospermia group. Total RNA in sperm was extracted from all subjects, and reverse transcription polymerase chain reaction (RT-PCR) was carried out to detect mRNA expressions of COXⅠand COXⅡ. Results: Compared with control group, mRNA expressions of COXⅠ(P <0.01) and COXⅡ(P < 0.05) were significantly decreased in asthenospermia group, but the sperm density in both groups showed no correlation with the mRNA levels of COXⅠand COXⅡ(r1=0.245, r2=0.029, P > 0.05). Conclusions: The down-regulation of COXⅠand COXⅡmRNA may be an important reason for poor motility of sperm; there may be no correlation between mRNA expressions of COXⅠ, COXⅡand sperm generation. PartⅡCorrelation of early stage apoptosis, mitochondrial membrane potential , content of reactive oxygen species and calcium ion in spermatozoa with sperm motilityObjective: To detect the percentage of early stage apoptosis, mitochondrial membrane potential(MMP), content of reactive oxygen species(ROS) and calcium ion in ejaculated spermatozoa between normal subjects and infertile males with asthenospermia, in order to explore the correlations of all these indexes with sperm motility. Methods: 50 semen samples were collected and divided into control group (n=20, sperm density≥20×106 / ml, a≥25% or a+b≥50%) and asthenospermia group (n=30, sperm density≥20×106 / ml, a<25% and a+b≤40%) according to sperm motility. All the samples were washed, followed by Annexin V-FITC/PI, JC-1, DCFH-DA and Fluo3-AM staining. Flow cytometry was used to detect percentage of sperm early stage apoptosis, mortality rate, MMP, the content of ROS and calcium ion in ejaculated spermatozoa. Results: Compared with control group, MMP was significantly decreased and the percentage of sperm early stage apoptosis was significantly increased in asthenospermia group (P < 0.01), and a positive correlation was found between the percentage of sperm early stage apoptosis and MMP deprivation (r1=0.673, r2=0.749, P < 0.01). Meanwhile the mortality rate, content of ROS and calcium ion were found no significant differences between two groups (P > 0.05). Conclusions: MMP deprivation and increased percentage of sperm early stage apoptosis may be reasons for poor sperm motility, and detection of MMP may have a great value in forecasting sperm early stage apoptosis. There may be no correlations of mortality rate, content of ROS and calcium ion in ejaculated spermatozoa with sperm motility.