Flow cytometric analysis of the maldescended testis

Effects of 50 Hz magnetic fields on mouse spermatogenesis monitored by flow cytometric analysis

Flow cytometry (FCM) was performed to monitor the cellular effects of extremely-low-frequency magnetic field on mouse spermatogenesis. Groups of five male hybrid F1 mice aged 8-10 weeks were exposed to 50 Hz magnetic field. The strength of the magnetic field was 1.7 mT. Exposure times of 2 and 4 h were chosen. FCM measurements were performed 7, 14, 21, 28, 35, and 42 days after treatment. For each experimental point, a sham-treated group was used as a control. The possible effects were studied by analyzing the DNA content distribution of the different cell types involved in spermatogenesis and using the elongated spermatids as the reference population. The relative frequencies of the various testicular cell types were calculated using specific software. In groups exposed for 2 h, no effects were observed. In groups exposed for 4 h, a statistically significant (P < 0.001) decrease in elongated spermatids was observed at 28 days after treatment. This change suggests a possible cytotoxic and/or cytostatic effect on differentiating spermatogonia. However, further studies are being carried out to investigate the effects of longer exposure times.

Cellular effects of image diagnostic ultrasound on murine spermatogenesis monitored by flow cytometry

A study has been carried out to evaluate the possible cellular effects induced by image diagnostic ultrasound on murine spermatogenetic cells. Exposure to ultrasound was carried out using a commercial diagnostic instrument that operates in B-mode. Male hybrid F1 mice, aged 8-10 weeks, were exposed to ultrasound for 30 min and observed from 7 to 35 days after treatment. Flow cytometric analysis has been used to monitor the relative frequency of the different types of spermatogenetic cells. This analytical approach showed changes in cell frequency in the compartment containing elongated spermatids which was used as an endpoint. A statistically significant decrease in the frequency of this cell type was observed 21, 28 and 35 days after exposure. These changes suggest that there may be a cytotoxic and/or cytostatic effect on spermatocytes and spermatogonia. These results showed that image diagnostic ultrasound induces effects on murine spermatogenesis at cellular level and that the flow cytometric approach makes it possible to identify quantitative cellular changes with reference to specific cell type.

The value of quantitative DNA flow cytometry of testicular fine-needle aspirates in assessment of spermatogenesis: a study of 137 previously maldescended human testes

In order to assess the suitability of DNA flow cytometry of fine-needle aspirates for quantifying spermatogenesis, the results from DNA flow cytometry were compared to histological evaluation of testicular biopsies taken concomitantly from 171 previously maldescended testes. In 137 of 171 cases, sufficient material for flow cytometric as well as histological evaluation was obtained. Histological analysis of surgical biopsy specimens revealed spermatogenesis including the spermatid stage in 117 of the 137 gonads. In six of the 117 gonads no haploid cells were found using flow cytometry. On the other hand, surgical biopsies failed to reveal spermatogenesis in five cases in which the corresponding aspirates contained haploid cells. Both methods therefore seem equally sensitive in detection of spermatogenesis. Other types of histological patterns also corresponded to distinct DNA histograms. Thus, in 11 of 12 cases with Sertoli-cell-only pattern in all tubules, at least 95% of the cells had a diploid DNA content. Furthermore, predominance of tubules with maturation arrest at the primary spermatocyte level corresponded to an increased proportion of tetraploid cells. When compared to surgical biopsy, DNA flow cytometry of testicular fine-needle aspirates is a more objective, easy and rapid method, which is more convenient for the patient. This study has indicated that DNA flow cytometry is a suitable method of quantitative assessment of spermatogenesis. One of the first target groups might be men with azoospermia. In such men, DNA flow cytometric analysis of fine-needle aspirates and surgical biopsy are apparently of equal sensitivity in detecting gonads with spermatogenesis. We conclude that DNA flow cytometry may become an alternative method for the quantification of spermatogenesis.

Cellular effects of diagnostic Doppler ultrasound on murine spermatogenic cells monitored by flow cytometry

A study has been carried out to investigate the possible effects caused by Doppler diagnostic ultrasound on murine spermatogenesis. The frequency of the different types of cells has been analyzed using flow cytometry. Exposure to ultrasound was carried out using a commercial device used in diagnostic conditions. Male hybrid mice were exposed to ultrasound for 30 min and observed from 7 to 35 days after treatment. Flow cytometrical analysis showed changes in the relative frequency of the elongated spermatids and this was used as an end-point. A statistically significant decrease in the frequency of this cell type was observed after 7 and 35 days with both pulsed and continuous ultrasound. With the former, a decrease was also seen in this compartment after 14 and 21 days. Our results have shown that diagnostic ultrasound used in the Doppler technique induces effects on specific cell types of murine spermatogenesis.

Flow cytometry of fine needle aspirations of the Sprague-Dawley rat testis: defining normal maturation and the effects of multiple biopsies

Quantitative assessment of spermatogenesis by flow cytometry reproducibly correlates with histological examination. Flow cytometry of fine needle aspirates from the testis was used to analyze normal spermatogenesis of Sprague-Dawley rats. Aged matched male weanlings were divided into 3 groups: group 1-5 rats underwent bilateral percutaneous aspiration of the testes with a 22 gauge Chiba needle on postpartum days 19, 24, 30 and 40; group 2-5 rats aspirated on days 24, 30 and 40, and group 3-4 rats aspirated on days 30 and 40. This sequential approach allowed for evaluation of normal spermatogenesis and the effects of repeated fine needle aspiration on spermatogenesis. Deoxyribonucleic acid distribution analysis by flow cytometry correlates with haploid (1N), diploid (2N), tetraploid (4N) and S phase cell populations. These cell populations were evaluated and comparisons among each group were made at all biopsy times. No significant differences in mean 2N, 4N or S phase cell populations in single versus repeat biopsied testes were detected. However, there was a significant increase in the 1N population at 30 days post partum in the repeat biopsy group (p = 0.037), which normalized by day 40. This increase in 1N corresponds to the beginning of meiosis, which is maximal between postpartum days 30 and 40, and occurs earlier in the repeat biopsied testis. Repeat fine needle aspiration of the testis can be performed without significantly affecting spermatogenesis in the "weanling" rat. This provides a useful technique in the future investigations of the time related effects of varicocele, chemotherapy and toxicologic drugs on spermatogenesis.

Effects of heat on mouse spermatogenesis monitored by flow cytometry

The effects of heat on mouse spermatogenesis have been determined using both testis weight and flow cytometrically determined DNA content distribution as experimental end-points. Temperatures of 38-42 degrees C and exposure times of 20-60 min have been tested. The results concerning the testis weight substantially confirm those reported by other authors (Hand et al. 1979). The measurement of DNA content distributions shows a relatively higher depletion, 14 days after treatment, of the cytometric compartment containing elongated spermatids in respect to that containing round spermatids. The analysis of the cytotoxic effects, monitored 14 vs. 28 days after treatment, as a function of the exposure time at a given temperature, or of the temperature for a fixed exposure time, indicates that, in the course of spermatogenesis, late spermatocytes are more sensitive to heat than differentiated spermatogonia. Following the approach based on flow cytometry, the effect of exposures as low as 20 min at 38 degrees C can be appreciated.

A comparative study of the effects of non-union of testis and epididymis and cryptorchidism on testicular development and spermatogenesis in the rat

Malunion of testis and epididymis is a congenital anomaly of human undescended testicles which may be of considerable clinical importance. In an experimental model in rat the effects of early disconnection of testis and epididymis (16 days) on testicular development have been testis and puberty. The results are compared with corresponding effects of cryptorchidism and sham-operation. The testes were weighed, and the relative proportions of haploid, diploid and tetraploid cells were quantified by DNA flow cytometry. The histology was evaluated by light and electron microscopy. The non-union operated testes showed a close to normal weight development until about 40 days of age, whereafter a decline occurred. The progression of the maturation division was only slightly reduced at 30 and 37 days of age, but later the spermatogenesis was significantly inhibited. At 58 days of age the maturation division had practically ceased in non-union operated testes. In cryptorchid animals the onset and progression of maturation divisions were almost totally depressed, and only traces of haploid cells were seen in some specimens. The transient increase in tetraploid cells, reflecting primary spermatocytes seen at about 30 days during normal testicular development, was neither depressed in non-union operated nor in cryptorchid animals. This indicates that the major block in spermatogenesis in both situations is at the stage of the primary spermatocytes. At 58 days of age the testicular histology was similar in non-union operated and cryptorchid testicles with many tubular sections showing only Sertoli cells. Scattered and partly degenerated germinal cells were seen in some sections. No histological signs of increased intratubular fluid pressure were detected, suggesting that pressure atrophy is not decisive for the reduced spermatogenesis in non-union operated gonads.

DNA-analysis of human testicular samples by cytofluorometry

Germ cells in human testicular samples have been estimated by histology and quantitated by flow cytometry. There is an excellent relationship between the two techniques. These samples were classified histologically as "normal", "reduced number of germ cells" or "no germ cells". A definition of "normalcy" as determined by flow cytometry as having at least 38% of the cells in the haploid state, is proposed. Testicular samples from prepubertal boys with infiltrating leukemic cells often show an increase in the percentage of S-phase cells indicating the presence of tumor. These results indicate the value of flow cytometry in the identification of reproductive and neoplastic disorders.