Sperm chromatin condensation, DNA integrity, and apoptosis in men with spinal cord injury

To evaluate the effect of cord injury on (1) sperm parameters and (2) DNA chromatin status.

Case-control study.

Data were collected from men referred to Research and Clinical Center for Infertility, Yazd, Iran.

Thirty infertile men with the presence of any level of spinal cord injury (SCI) were compared with 30 healthy donors with definite fertility and normal sperm parameters.

Not applicable.

Sperm chromatin integrity was assessed using aniline blue (AB), chromomycin A3 (CMA3), toluidine blue (TB), and acridine orange (AO) assays. The rate of apoptotic spermatozoa was evaluated with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) staining.

Sperm concentration, motility, and morphology in men with SCI were significantly decreased compared with control group (P < 0.05). In addition, with regard to cytochemical staining and TUNEL test, the rate of reacted spermatozoa was increased significantly in SCI group when compared with the controls (P < 0.05). The majority of AB, TB, AO, and CMA3-reacted spermatozoa were higher than the "cut-off" value in men with SCI, as were the number of apoptotic spermatozoa stained with TUNEL.

Results showed that SCI disturbs sperm parameters, nuclear maturity, and DNA integrity of spermatozoa. Therefore, the production of spermatozoa with less condensed chromatin and more apoptotic rate increases after cord injury and this may be one possible cause of infertility following SCI.