Characterization of ultrastructural and metabolic abnormalities in semen from men with spinal cord injury.
BACKGROUND
In men with spinal cord injury (SCI), fertility is impaired because of a combination of ejaculatory dysfunction and poor semen quality. We hypothesized that ultrastructural and metabolic abnormalities of sperm could be an underlying factor in infertility in these men.


METHODS
To investigate mechanisms contributing to the abnormal sperm parameters, we analyzed seminal constituents and sperm ultrastructure in ejaculates from 7 men with SCI and compared them with 5 control subjects. Sperm adenosine triphosphate (ATP) content was measured using a firefly luciferase bioluminescent assay kit, and ultrastructure was evaluated by electron microscopy. Seminal oxidative stress (8-iso-prostaglandin F-2alpha [8-iso-PGF2alpha]) and transforming growth factor-beta1 (TGF-beta1) levels were measured by specific enzyme-linked immunoabsorbent assay kits.


RESULTS
Semen samples from men with SCI showed azoospermia (3) and severe asthenospermia (2; motility 0-5%). A majority (65%) of sperm from asthenospermic samples showed degenerative changes and significant axonemal defects. Incubation of normal sperm with SCI seminal plasma induced a concentration-dependent decrease in sperm motility (43%) accompanied by a significant drop in intracellular ATP content (33%). Semen samples from men with SCI exhibited levels of 8-iso-PGF2alpha 3.5-fold higher than those from controls and levels of TGF-beta1 that were 10% higher than those from controls.


CONCLUSIONS
Our results suggest that seminal constituents of men with SCI are detrimental to sperm movement and that ultrastructural degenerative changes may contribute to the impaired sperm motility and viability seen in these patients. These preliminary results must be confirmed in larger patient populations and longitudinal studies.
Monga
M
M
Division of Urology, University of California San Diego Medical Center, 92103-8897, USA. mmonga@ucsd.edu
Dunn
K
K
Rajasekaran
M
M
D000328:Adult; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D012661:Semen / Q000378:metabolism* / Q000502:physiology*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure*; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000503:physiopathology*; D016212:Transforming Growth Factor beta / Q000032:analysis
D016212:Transforming Growth Factor beta