Effect of fructose on motility, acrosome reaction and in vitro fertilization capability of boar spermatozoa

Aim:  The present study was carried out to investigate the effects of fructose supplementation in glucose containing mTALP medium on motility, acrosome reaction and in vitro fertilization capability of boar spermatozoa.
Methods:  Boar spermatozoa were preincubated, swum-up, resuspended and then incubated for 6 h in mTALP medium supplemented with 0, 0.5, or 1.0 mmol fructose in the presence of 5.0 mmol glucose. After completion of the specified incubation period, motility was determined subjectively on the basis of speed of progression and on the type of forward movement of spermatozoa; acrosome status was evaluated by applying a triple staining technique; and in vitro fertilization capability was assessed by acetic–orcein staining.
Results:  The combination of fructose and glucose (0.5 + 5.0 mmol) supplements in mTALP medium improved sperm motility significantly ( P <  0.05), more than glucose alone (5.0 mmol) at 2–6 h of incubation. Acrosome reaction (live spermatozoa) and the sperm penetration rate was increased significantly ( P <  0.05) when the spermatozoa were treated with the combination of fructose and glucose compared with glucose alone, but the incidence of polyspermy was not significantly different between the treatments.
Conclusion:  These results suggest that the combination of glucose and fructose as supplements in mTALP medium improve the progressive motility, acrosome reaction and fertilization capability of boar spermatozoa. (Reprod Med Biol 2006; 5: 255–261)     

Effect of fatty acids bound to bovine serum albumin-V on acrosome reaction and utilization of glucose in boar spermatozoa

Aim:  The present study has been designed with the objective of determining if fatty acids bound to bovine serum albumin-V (BSA-V) can improve motility, viability, and increase acrosome reaction (AR) and utilization of glucose in boar spermatozoa.
Methods:  Boar spermatozoa were washed, swum-up and incubated at 37°C for 6 h in TALP medium supplemented with fatty acids bound to bovine serum albumin fraction V (BSA-V), fatty acid free BSA (BSA-FAF), polyvinyl alcohol + main fatty acids bound to BSA-V (PVA + FA) and PVA. Sperm motility, viability, AR, and the incorporation and oxidation of ¹⁴C-glucose were evaluated during 6 h of incubation.
Results:  The results show that the BSA-V was superior to BSA-FAF and PVA in improving motility and AR. Viability was significantly increased ( P  < 0.05) by only BSA-V compared with PVA. When the main fatty acids compound of BSA-V were added to PVA, the sperm motility, viability and AR became almost the same as with BSA-V. The rate of incorporation and oxidation of ¹⁴C-glucose were significantly increased ( P  < 0.05) by BSA-V compared with BSA-FAF and PVA. Fatty acids bound to BSA-V are important for improvement of sperm functions.
Conclusions:  The present study postulates that fatty acids bound to BSA-V are important to acrosome reaction and the utilization of glucose in boar spermatozoa.     

Effects of relaxin and IGF-I on capacitation, acrosome reaction, cholesterol efflux and utilization of labeled and unlabeled glucose in porcine spermatozoa

Aim:  Relaxin and insulin-like growth factor (IGF)-I have pronounced effects on the male and female reproductive tracts. The aim of this study was to investigate the effects of relaxin and IGF-I on the motility, capacitation, acrosome reaction, cholesterol efflux and utilization of glucose in porcine spermatozoa.
Methods:  Swim-up separated spermatozoa that had been washed twice were incubated at 37°C for 1 or 4 h in modified Tyrode's albumin lactate pyruvate (mTALP) medium supplemented without (control) or with relaxin (20 ng/mL) or IGF-I (20 ng/mL) or both (10 + 10 ng/mL).
Results:  Progressive motility and the induction rate of capacitation and acrosome reaction were increased ( P <  0.05) by relaxin and IGF-I alone or in combination, especially after 4 h of incubation. Relaxin alone or combined with IGF-I enhanced ( P  < 0.05) the cholesterol efflux after 4 h, whereas IGF-I alone did not show any significant effect on the cholesterol efflux compared with the control at any time point. The utilization rates of labeled and unlabeled glucose increased ( P <  0.05) in spermatozoa incubated with relaxin or IGF-I alone or in combination compared with the control.
Conclusion:  Thus, supplementation of relaxin alone or combined with IGF-I into the medium possibly plays a beneficial role in porcine spermatozoal prefertilization events in vitro . (Reprod Med Biol 2008; 7 : 29–36)     

The monoclonal antibody GZS-1 detects a maturation-associated antigen of human spermatozoa that is also present on the surface of human mononuclear blood cells

A monoclonal antibody (GZS-1) has been generated by fusion of mouse myeloma cells with spleen cells from BALB/c mice immunised with human sperm cells. The antibody was determined to be an IgG₁. The corresponding antigen is present on the whole surface of ejaculated human spermatozoa. It is not detectable on spermatozoa of other mammalian species (rabbit, cat, dog, sheep, boar, bull, horse). In human male genital organs, immunostaining with GZS-1 is observed on sperm cells in the epididymis and the ductus deferens together with the lining epithelium of those organs. No reactivity of sperm cells or germ cell precursors in the testis has been detected. Functional tests using the antibody show a strong inhibitory effect on human sperm in the hamster egg penetration assay. Furthermore, the GZS-1 antigen is detectable on the surface of human lymphocytes and monocytes by immunogold electron microscopy and FACS analysis. By Western blotting of human sperm and seminal plasma performed under reducing conditions immunostaining was detected at 21–25, 31, 51–54, and 62 kDa. The reaction with human lymphocytes shows one major band at 62 kDa and additional bands at 31 and 54 kDa. The results suggest that the monoclonal antibody GZS-1 may recognise an antigen which is secreted from the epithelial cells of the epididymis and binds to ejaculated spermatozoa as a sperm coating antigen. This component may be involved in the capacitation of the sperm and the acrosome reaction. Molecules that are expressed both on sperm and on immunocompetent cells may be relevant for the regulation of immunological processes or for the development of the related immunological tolerance of sperm in the female reproductive tract.     

Comparison of intrabursal transfer of spermatozoa,a new method for artificial insemination in mice,with intraoviductal transfer of spermatozoa

Purpose : The objective of this paper was to compare the in vivo fertilizing abilities of fresh epididymal spermatozoa with a new method of artificial insemination in mice, so-called intrabursal transfer of spermatozoa (ITS), which requires transfer of spermatozoa into a space near the infundibulum between the ovary and ovarian bursa of superovulated females, and the previous method, so-called intraoviductal transfer of spermatozoa (IOTS), especially as regards sperm number and capacitation. Methods : Spermatozoa freshly isolated from B6C3F1 males were injected into superovulated B6C3F1 females on E 0.4 (10:00 AM) by the IOTS or ITS method. Embryos at two-cell stage were collected from the females 1 day after injection and their morphology was scored. Some females were allowed to survive at midgestational stages and inspected for development of normal fetuses. Results : When 1 L of a sperm suspension containing uncapacitated 1 × 10⁵ spermatozoa freshly isolated from B6C3F1 males was injected by the IOTS or ITS method, normal two-cell embryos were recovered from the females at rates ranging from 14 to 23% with each method. This rate was much lower than that (93% on average) for embryos obtained by natural mating. Neither injection of 1 × 10³ or 1 × 10⁴ spermatozoa nor induction of capacitation improved in vivo fertilization rate. In both cases, females given spermatozoa exogenously yielded midgestational fetuses (E 12.5–13.5) with average litter sizes between 2.5 and 2.8. Conclusion : ITS was comparable to IOTS with the conditions used. These two methods will be valuable for artificial insemination in mice for propagation of offspring from particular transgenic or mutant lines that are difficult to breed, although further attempts to improve in vivo fertilization ability are required.