Co-incubation of human spermatozoa with anti-VDAC antibody reduced sperm motility.
BACKGROUND
Voltage-dependent anion channel (VDAC), a channel protein, exists in the outer mitochondrial membrane of somatic cells and is involved in multiple physiological and pathophysiological processes. Up until now, little has been known about VDAC in male germ cells. In the present study, the relationship between VDAC and human sperm motility was explored.


METHODS
Highly motile human spermatozoa were incubated in vitro with anti-VDAC antibody. Total sperm motility, straight line velocity (VSL), curvilinear velocity (VCL), and average path velocity (VAP) were recorded. Intracellular free calcium concentration ([Ca(2+)]i), pH value (pHi), and ATP content were determined.


RESULTS
Co-incubation with anti-VDAC antibody reduced VSL, VCL, and VAP of spermatozoa. Co-incubation further reduced [Ca(2+)]i. Anti-VDAC antibody did not significantly alter total sperm motility, pHi and intracellular ATP content.


CONCLUSIONS
The data suggest that co-incubation with anti-VDAC antibody reduces sperm motility through inhibition of Ca(2+) transmembrane flow. In this way, VDAC participates in the modulation of human sperm motility through mediating Ca(2+) transmembrane transport and exchange.
State Key Laboratory of Reproductive Medicine and Department of Urology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Bianjiang
B
Liu
Min
M
Tang
Zhijian
Z
Han
Jie
J
Li
Jiexiu
J
Zhang
Pei
P
Lu
Ninghong
N
Song
Zengjun
Z
Wang
Changjun
C
Yin
Wei
W
Zhang
D000255:Adenosine Triphosphate / Q000378:metabolism; D000906:Antibodies / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D006863:Hydrogen-Ion Concentration; D042541:Intracellular Space / Q000378:metabolism; D008297:Male; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism*; D050994:Voltage-Dependent Anion Channels / Q000037:antagonists & inhibitors*
D000906:Antibodies; D050994:Voltage-Dependent Anion Channels; D000255:Adenosine Triphosphate; D002118:Calcium