Altered ultrastructure of mitochondrial membranes is strongly associated with unexplained asthenozoospermia.
OBJECTIVE
To explore the contribution of an altered structure of sperm mitochondria to human asthenozoospermia.


METHODS
A retrospective study.


METHODS
Andrology Clinic, University of L'Aquila.


METHODS
Fifteen ejaculates with forward motility (FM) ≥ 50%, and 57 asthenozoospermic ejaculates (FM <50%, sperm vitality >50%), including 14 ejaculates with systematic genetic defects of tail principal piece, and 43 ejaculates with unexplained asthenozoospermia.


METHODS
Fifty sections of tail middle piece (MP) were blindly analyzed by transmission electron microscopy in each ejaculate for normal mitochondrial membrane organization, after exclusion of tails with disrupted cell membranes.


METHODS
Percentage of MPs with normal mitochondrial membranes (% normal MPs).


RESULTS
Percent normal MPs showed a strong correlation with forward motility. Variation of % normal MPs explained a 45% variation of sperm motility at multivariate linear regression analysis, confirming the strong association between the two parameters in a population including ejaculates with normal motility and with unexplained asthenozoospermia. Percent normal MPs was significantly reduced in severe unexplained asthenozoospermia (FM <10%; n = 16) compared with samples with normal motility (FM ≥ 50%; n = 15); 21% (10.5%-38%) and 68% (52%-73%), respectively.


CONCLUSIONS
Structural defects in mitochondrial membranes represent a main feature of severe unexplained asthenozoospermia.
Pelliccione
Fiore
F
Andrology Unit, Department of Internal Medicine, University of L'Aquila, L'Aquila, Italy.
Micillo
Alessandro
A
Cordeschi
Giuliana
G
D'Angeli
Anatolia
A
Necozione
Stefano
S
Gandini
Loredana
L
Lenzi
Andrea
A
Francavilla
Felice
F
Francavilla
Sandro
S
D053627:Asthenozoospermia / Q000150:complications* / Q000453:epidemiology / Q000473:pathology; D004542:Ejaculation; D006801:Humans; D008297:Male; D028361:Mitochondrial Diseases / Q000150:complications* / Q000453:epidemiology; D051336:Mitochondrial Membranes / Q000648:ultrastructure*; D012189:Retrospective Studies; D055101:Semen Analysis; D053625:Sperm Retrieval; D013082:Sperm Tail / Q000473:pathology / Q000648:ultrastructure; D013094:Spermatozoa / Q000002:abnormalities / Q000473:pathology / Q000648:ultrastructure