Biologic response of sperm and seminal plasma to transient testicular heating.

Currently, there are few male contraceptive methods that are purely based on prevention of the entry of the sperm into the female reproductive tract. An alternative approach for designing reversible male contraceptive is achieved by transient testicular heating (TTH). This treatment, through massive germ cell apoptosis, causes reversible oligospermia or azoospermia. Here, we describe as how TTH causes DNA damage, oxidative stress, apoptosis, autophagy, sperm protein expression, and alters the biochemical components of seminal plasma. Further understanding of TTH will help design safe and reversible male contraception.

Effect of scrotal heating on sperm quality, seminal biochemical substances, and reproductive hormones in human fertile men.

At present, male contraceptive methods are only vasectomy and condoms, so it is necessary to research on male contraceptive techniques. The aim of this study is to observe the effects of scrotal heating (SH) on semen parameters, seminal l-carnitine (LC), epidermal growth factor (EGF), macrophage migration inhibitory factor (MIF), reproductive hormones and sperm chromosome numbers of adult healthy men, and to provide the experimental data for male contraception. The scrotums of 30 healthy male volunteers were exposed to the condition of 40 to 43°C SH belt warming 40 minutes each day for successive 2 days per week. The course of SH was continuous for 3 months. Computer-assisted semen analysis and hypo-osmotic swelling test, sperm DNA integrity, l-carnitine, MIF and EGF, and sperm fluorescence in situ hybridization were performed before, during, and after SH. The serum level of follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) were measured by chemiluminescent immunoassay. The mean parameters of sperm concentration, vitality, and normal morphological sperm were significantly decreased in groups with sperms being collected during 1, 2, and 3 months of SH when compared with those in groups of pre-SH (P < 0.01). Statistically significant differences of sperm DNA fragmentation, normal sperm membrane functionality, levels of LC and MIF in semen, and LH, FSH, and T in serum were observed between the groups of before SH and after SH 3 months and the groups of during SH 1, 2, and 3 months (P < 0.001). The total rate of chromosome number for 13, 18, 21, X, and Y in the 3 months of SH was 13.7-fold greater (13.72%/1.69%) than before SH (P < 0.001). The constant SH can impact the semen quality, sperm DNA integrity, sperm chromosome, LC and MIF, and LH, FSH, and T in serum. Transient SH may be a new method for male contraception.

[Yam polysaccharide improves sperm viability and protects sperm DNA integrity in vitro].

OBJECTIVE: To clarify the roles of yam polysaccharide (YPS) in improving sperm viability and protecting sperm DNA integrity in vitro and provide a new approach to the treatment of oligoasthenozoospermia. METHODS: We collected samples by masturbation from 36 normal fertile males aged 27－39 years. Each sample was divided into six groups: blank control or treated with normal saline, vitamin C solution, and YPS solution at low (0.25 mg/ml), medium (1.0 mg/ml) or high concentration (5.0 mg/ml). Using eosin-Y staining, sperm hypotonic swelling (HOS) and sperm chromatin diffusion (SCD) test, we observed the effects of different concentrations of YPS on sperm viability, membrane integrity and nuclear DNA. RESULTS: After 24 and 48 hours of treatment, sperm viability was markedly reduced in the vitamin C (ï¼»28.5 ± 3.1ï¼½ and ï¼»6.5 ± 1.2ï¼½%), low-YPS (ï¼»31.3 ± 3.5ï¼½ and ï¼»6.5 ± 2.2ï¼½%), medium-YPS (ï¼»37.1 ± 3.5ï¼½ and ï¼»9.5 ± 2.8ï¼½%) and high-YPS groups (ï¼»38.3 ± 3.3ï¼½ and ï¼»9.0 ± 3.2ï¼½%) as compared with the blank control (ï¼»17.3 ± 2.1ï¼½ and ï¼»3.2 ± 1.3ï¼½%) (P <0.01) and normal saline groups (ï¼»13.4 ± 4.1ï¼½ and ï¼»3.1 ± 2.0ï¼½%) (P <0.01), and it was significantly higher in the medium- and high-YPS than in the vitamin C group (P <0.05 and P <0.01). The rate of sperm DNA fragmentation was remarkably decreased at 48 hours in the vitamin C (ï¼»30.5 ± 3.1ï¼½%), low-YPS (ï¼»29.4 ± 2.6ï¼½%), medium-YPS (ï¼»28.5 ± 2.3ï¼½%) and high-YPS groups (ï¼»27.9 ± 1.9ï¼½%) in comparison with the blank control (ï¼»41.7 ± 2.2ï¼½%) (P <0.01) and normal saline groups (ï¼»42.1 ± 3.3ï¼½%), markedly lower in the medium- and high-YPS than in the blank control, normal saline and vitamin C groups (P <0.05 or P <0.01), but with no statistically significant difference between the low-YPS and vitamin C groups (P >0.05). CONCLUSIONS: Yam polysaccharide can improve sperm viability and protect sperm DNA integrity in vitro.