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Morphological characteristics of spermatozoa before and after renal transplantation
Long-Gen Xu1 , Shi-Fang Shi2 , Xiao-Ping Qi1, Xiao-Feng Huang3, Hui-Ming Xu4, Qi-Zhe Song1, Xing-Hong Wang1, Zong-Fu Shao1, Jun-Rong Zhang4
Transplantation Center, 117th Hospital of PLA, Hangzhou 310013, China
Correspondence to: Dr. Long-Gen Xu, Renal Transplantation Center, 117th Hospital of PLA, Hangzhou 310013, China.
Tel/Fax: +86-571-8796-2610 E-mail: email@example.com
Received 2003-11-17 Accepted 2004-10-18
Aim: To investigate the changes of the spermatozoa ultrastructures before and after renal transplantation in uremic patients. Methods: The sperm of five uremic patients before and after transplantation and four healthy volunteers were collected and examined by scanning electron microscopy. Results: Abnormal spermatozoa were found in patients pre-transplantation; abnormalities included deletion of the acrosome, absence of the postacrosomal and postnuclear ring, dumbbell-like changes of the head, tail curling, and absence of the mitochondrial sheath in the mid-segment. After renal transplantation, most of the spermatozoa became normal. Conclusion: There are many abnormalities with regard to the appearance and structure of the head, acrosome, mitochondria and tail of the spermatozoa in uremic patients. The majority of the spermatozoa returned to normal after renal transplantation, but a few still presented some abnormalities possibly relating to the administration of immunosuppressants. (Asian J Androl 2005 Mar; 7: 81-85)
Keywords: uremia; renal transplantation; spermatozoa; scanning electron microscopy
Previous investigations have indicated that many abnormalites of spermatozoa in uremic patients were corrected after successful renal transplantation .
The present study used scanning electron microscopy (SEM) to further investigate the morphological and ultrastructural changes of the spermatozoa in these patients before and after renal transplantation.
2 Materials and methods
2.1 Clinical characteristics
Our study included five uremic male patients aged 27 to 38 (mean 31) years, all married with healthy children. All had sufferred with chronic glomerulonephritis for a period of 12 to 35 (mean 21.6) months. Hemodialysis (2-3 times per week) was maintained for 2-13 months (mean 7.2) before sperm inspection. Eight to fifteen (mean 12.2) months after successful transplantation the sperm were again collected for inspection. Sperm from four healthy men aged 30-32 (mean 31.3) years (volunteers from the hospital staff) were also examined as controls. All the patients and volunteers were nonsmokers and nondrinkers. Written informed consent was obtained from every subject before the study commenced.
Sperm were collected by means of masturbation following at least 3 days of abstention. Sperm were liquefied at room temperature for 30 min, diluted and centrifugalized at 2000 rpm for 10 min. Following removal of supernatants, specimens were washed with normal saline and centrifuged again. The sediment was then aspirated and 2 mL of glutaric dialdehyde (2.5 %) were added. After fixation, drying, desiccation and aurum spraying, the spermatozoa were examined with SEM (Cambridge S260, UK).
3.1 Spermatozoa in healthy men
A normal human spermatozoon was tadpole-like with a head and a tail. The head was 4-5 mm long. The length of the main-, mid- and end-segment of the tail was appproximately 45, 5-7 and 5 mm, respectively. Both the head and tail were well developed. The structure of the acrosomal membrane was integrated with a clear demarcation among the postacrosomal and postnuclear ring and each segment of the tail (Figure 1).
3.2 Spermatozoa in uremic patients
Different kinds of deformity in the spermatozoa were observed under SEM. The head presented the following anomalies: (1) absence of the acrosome, indistinct post-acrosomal and postnuclear ring (Figures 2, 3); (2)dumb-bell-like head with irregular contour (Figure 4); and (3) coarseness and unevenness of the surface, absence of the postacrosomal and postnuclear ring (Figure 5). The deformities of the tail included: (1) indistinct mitochondrial sheath in the mid-segment (Figures 2, 4); (2) obvious curl of the tail encircling the head (Figure 5); and (3) mixed deformities (i.e. two or more abnormalities present in a single spermatozoon) (Figures 2-5).
3.3 Spermatozoa in post-transplanted patients
The majority of the spermatozoa was normal after renal transplantation (Table 1). Under SEM both the head and tail could be seen distinctly. The ultrastructure of the acrosome turned towards integrated, the post-acrosomal and postnuclear ring were dimly visible. No obvious abnormalities could be observed (Figure 6). A few spermatozoa showed an irregular configuration in the head but had a normal tail (Figure 7).
The abnormalities of the spermatozoa in uremic patients were much more visible by SEM than by light microscopic examination. Prem et al.  reported the results of sperm analysis in 19 male patients 6 months after maintained hemodialysis; testis biopsy was undertaken in eight patients with azoospermia or oligozoospermia. Of these there were three patients with hypo-spermato-genesis, four with retardation of spermatozoal maturity and one with dysplasia of gonobasts. Wu et al.  reported that the quality of the sperm was greatly decreased in uremic patients, which might be related to the absence of the mitochondrial sheath found in this study. Yogev et al.  reported that in five of six uremic rats, spermatogenic systems and fertility basically remained normal other than a slight reduction in the blood testosterone level after nephrectomy. The dissimilarity in results of these studies may be due to species difference. Prem et al.  examined the sperm in 19 patients 6 months after renal transplantation. They found the quality of the sperm was improved, and the density and activity of the sperm were greatly increased. Testicular biopsy was carried out in seven patients; of those spermatogenesis returned to normal in four and maturity retardation of the spermatozoa remained in three [1, 4]. Holdsworth et al. also found successful renal transplantation played a significant role in the improvement of the testicular function impaired by uremia . Our study showed that the configuration of the spermatozoa returned distinctly to normal following renal transplantation. These findings demonstrated that after transplantation the restoration of the configuration of the spermatozoa did occur to a certain extent. Nevertheless, there still remained certain abnormalities in a few spermatozoa as mentioned also by Prem et al. . On the other hand we think the side-effects of immunosuppressant cyclosporin A (CsA) should also be considered. In the animal experiment there was no damage to the testicles at a CsA dose of 10 mg.kg-1, but when the dose was increased to ¡Ý20 mg.kg-1, a decrease in testicular weight, activity and quantity of the spermatozoa and degeneration, and necrosis of Leydig and Sertoli cells would occur . Li et al. reported the effects of different CsA dosage on rat testes by transmission electron microscopy. They found the development of the seminiferous epithelia and spermatozoa were inhibited at a dose of 10 mg.kg-1, the structural changes of the seminiferous epithelia and spermatozoa, degeneration and necrosis of the spermatocytes and spermatoblasts followed by abnormal development of the spermatozoa occurred at a dose of 20 mg.kg-1. Hanbermen et al. reported that of nine post-transplanted patients treated with CsA at a dose of 3 mg.kg-1.day-1, sperm analysis was normal in eight patients . Thus there exists a correlation between the recovery of a spermatozoa deformity and the CsA dosage. It was demonstrated that a blood concentration of CsA greater than 600 µg.L-1 was the potential toxic concentration . Therefore, we suggest that a lower dose CsA administration and a close monitoring of the CsA blood concentration are essential strategies for the restoration of the spermatozoa function after renal transplantation.