DNA flow cytometry of left and right testes in normospermic patients affected by left varicocele.

Abstract

To assess whether changes in spermatogenesis are present in men suffering from varicocele who are still normospermic, a comparative flow cytometric analysis of the left and right testicular DNA content was performed on 26 young normospermic males (sperm density > 20 x 10(6)/ml), with varying degrees of asthenospermia. Cell samples were obtained by fine needle aspiration biopsy. Flow cytometric analysis revealed four peaks in the nuclear DNA content: (i) two peaks for haploid cells (1-A), the first composed of highly condensed nuclear cells (1Ac), essentially spermatozoa, and the second of less condensed cells, essentially spermatids (1-Anc): (ii) a third peak of diploid cells (2-D): somatic cells, G1-stage spermatogonia, primary and secondary spermatocytes and (iii) a fourth peak of tetraploid cells, essentially postleptotene primary spermatocytes and G2-M-stage spermatogonia (4-T). Flow cytometry showed the left testis to have a lower percentage of haploid cells than the right (mean 48.4 +/- 17.9 versus 57 +/- 15.4%, P < 0.05). Significantly fewer condensed cells were found on the left side than on the right (respectively 19.7 +/- 11.2 versus 31.5 +/- 13.5%, P < 0.004). The diploid cell percentage was significantly higher in the left testis than in the right (37.0 +/- 18.5 versus 25.5 +/- 9.6, P < 0.003). No statistically significant differences were found in respect of percentages of either non-condensed and tetraploid cells (respectively 26.6 +/- 14.8 and 11.3 +/- 5.6 on the left and 25.9 +/- 10.3 and 12.4 +/- 6.2 on the right). Flow cytometric analysis of cadaver biopsy tissue showed no statistically significant difference between left and right testicles in respect of the percentages of haploid, diploid and tetraploid cells. The reduced percentage of haploid cells and the increase in diploid cells observed in the left testis of our subjects indicate that the testicular function is impaired to a greater extent in the testis ipsilateral to varicocele than in the contralateral testicle.