Abstract
Purpose:The objectives of this study were (1) to determine the sperm hyperactivation and related kinematic parameters at 40°C after using four sperm wash procedures and (2) to correlate the heat-induced hyperactivation data with cases of clinical pregnancies from either artificial insemination or standard in vitro fertilization (IVF).
Methods:Semen samples (n = 51) were collected by ejaculation, and semen analyses were carried out to determine the pretreatment data. Sperm kinematic measurements were performed using the Hamilton Thorn HTM-C computer-aided sperm analyzer. Hyperactivation was determined using the sort module on the HTM-C. Membrane integrity was assessed using the hypoosmotic sperm swelling procedure. Sperm morphology and acrosomal status were also determined using the Spermac stain. Each semen specimen was divided and processed through either the swim-up wash, the 1-h test-yolk buffer (TYB) wash, the 1 mg/ml pentoxifylline stimulant procedure, or the two-layer 90:47% gradient colloidal solution procedure. The washed sperm were incubated at 25 or at 40° C for 4 hr. After incubation, kinematic parameters were assessed for the posttreatment data. Semen specimens were obtained on different occasions for artificial insemination or standard IVF. Data from intracytoplasmic sperm injection cases were not included to avoid confounding factors. Live births and/or pregnancies with fetal heartbeat examined by ultrasound were considered clinical pregnancies.
Results:Heat-induced hyperactive motility was significantly higher in sperm of the male partner of pregnant (n = 7) patients compared with nonpregnant (n = 44) patients (mean ± SE, 10.0 ± 3.3 versus 5.5 ± 0.8%) after TYB processing fallowed by 4 hr of incubation at 40°C. This was also observed after colloid (Percoll) processing (11.6 ± 4.6 versus 5.8 ± 0.8%). There were no differences in hyperactivation after 4 hr at 23°C between pregnant and nonpregnant cases. Parameters such as count, volume, motility, viability, and acrosomal status were not different for the groups. However, the percentage of sperm with normal morphology (WHO classification) was twice as high in the pregnant group versus the nonpregnant group.
Conclusions:Heat-induced hyperactivation was associated with fertile sperm and was predictive of pregnancy obtained after artificial insemination or IVF. The association was evident only after TYB or Percoll sperm processing. The study could not confirm the finding of significant decreases in motility after heat treatment of sperm derived from infertile males. The mechanism for heat-induced hyperactivation did not involve membrane integrity or the sperm acrosome, although an involvement of heat shock proteins was postulated. Interestingly, there were no pregnancies when sperm did not exhibit heat-induced hyperactivation.
Keywords: sperm, computer-aided sperm analyzer (CASA), induction, hyperactivation motility
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REFERENCES
- 1.Alvarez JG, Minaretzis D, Barrett CB, Mortola JF, Thompson IE. The sperm stress test: A novel test that predicts pregnancy in assisted reproductive technologies. Fertil Steril. 1996;65:400–405. doi: 10.1016/s0015-0282(16)58107-2. [DOI] [PubMed] [Google Scholar]
- 2.Austin CR. Capacitation of spermatozoa. Int J Fertil. 1967;12:25–31. [PubMed] [Google Scholar]
- 3.Yanagimachi R. The movement of golden hamster spermatozoa before and after capacitation. J Reprod Fertil. 1970;23:193–196. doi: 10.1530/jrf.0.0230193. [DOI] [PubMed] [Google Scholar]
- 4.Burkman LJ: Movement characteristics of four classes of human sperm hyperactivation: Criteria for computerized identification. Proc 45th Annu Mtg Am Fertil Soc, 1989, p 66
- 5.Fraser LR. Motility patterns in mouse spermatozoa before and after capacitation. J Exp Zool. 1977;202:439–444. doi: 10.1002/jez.1402020314. [DOI] [PubMed] [Google Scholar]
- 6.Johnson LL, Katz DF, Overstreet JW. The movement characteristics of rabbit spermatozoa before and after activation. Gamete Res. 1981;4:275–282. [Google Scholar]
- 7.Cummins JM. Hyperactivated motility patterns of ram spermatozoa recovered from the oviducts of mated ewes. Gamete Res. 1982;6:53–63. [Google Scholar]
- 8.Suarez SS, Vincenti L, Ceglia MW. Hyperactivated motility induced in mouse sperm by calcium A23187 is reversible. J Exp Zool. 1987;244:331–336. doi: 10.1002/jez.1402440218. [DOI] [PubMed] [Google Scholar]
- 9.Perreault S, Rogers BJ. Capacitation pattern of human spermatozoa. Fertil Steril. 1982;38:258–260. [PubMed] [Google Scholar]
- 10.Burkman LJ. Discrimination between nonhyperactivated and classical hyperactivated motility patterns in human sperm using computerized analysis. Fertil Steril. 1991;55:363–371. [PubMed] [Google Scholar]
- 11.McClure RD, Nunes L, Tom R. Semen manipulation: Improved sperm recovery and function with a two-layer Percoll gradient. Fertil Steril. 1989;51:874–877. doi: 10.1016/s0015-0282(16)60683-0. [DOI] [PubMed] [Google Scholar]
- 12.Katayama KP, Stehlik E, Roesler M, Jeyendran RS, Holmgren WJ, Zaneveld LJD. Treatment of human spermatozoa with an egg yolk medium can enhance the outcome of in vitro fertilization. Fertil Steril. 1989;52:1077–1079. doi: 10.1016/s0015-0282(16)53181-1. [DOI] [PubMed] [Google Scholar]
- 13.Pang SC, Chan PJ, Lu A. Effects of pentoxifylline on sperm motility and hyperactivation in normozoospermic and normokinetic semen. Fertil Steril. 1993;60:336–343. doi: 10.1016/s0015-0282(16)56108-1. [DOI] [PubMed] [Google Scholar]
- 14.Chan PJ, Corselli JU, Jacobson JD, Patton WC, King A. Correlation between intact sperm acrosome assessed using the Spermac stain and sperm fertilizing capacity. Arch Androl. 1996;36:25–27. doi: 10.3109/01485019608987881. [DOI] [PubMed] [Google Scholar]
- 15.Eliasson R, Treichl MB. Supravital staining of human spermatozoa. Fertil Steril. 1971;22:134–137. doi: 10.1016/s0015-0282(16)38049-9. [DOI] [PubMed] [Google Scholar]
- 16.Chan PJ, Tredway DR, Corselli J, Pang SC, Su BC. Combined supravital staining and hypoosmotic swelling test. Hum Reprod. 1991;6:1115–1118. doi: 10.1093/oxfordjournals.humrep.a137495. [DOI] [PubMed] [Google Scholar]
- 17.Corfman RS, Milad MP, Bellavance TL, Ory SJ, Erickson LD, Ball GD. A novel ovarian stimulation protocol for use in assisted reproductive technologies. Fertil Steril. 1993;60:864–870. doi: 10.1016/s0015-0282(16)56288-8. [DOI] [PubMed] [Google Scholar]
- 18.Edwards RG, Brody SA (eds): Evaluation and treatment of the infertile woman. In Principles and Practice of Assisted Human Reproduction. Philadelphia, W. B. Saunders, 1996, pp 150–301
- 19.Dix DJ, Allen JW, Collins BW, Mori C, Nakamura N, Poorman-Allen P, Goulding EH, Eddy EM. Targeted gene disruption of Hsp70-2 results in failed meiosis, germ cell apoptosis, and male infertility. Proc Natl Acad Sci USA. 1996;93:3264–3268. doi: 10.1073/pnas.93.8.3264. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Yang RC, Shen MR, Chiang PH, Yang SL, Chen SS. A possible role of heat shock proteins in human sperm motility. Kao Hsiung I Hsueh Ko Hsueh Tsa Chih. 1992;8:299–305. [PubMed] [Google Scholar]
- 21.Newton EM, Knauf U, Green M, Kingston RE. The regulatory domain of human heat shock factor 1 is sufficient to sense heat stress. Mol Cell Biol. 1996;16:839–846. doi: 10.1128/mcb.16.3.839. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Burkman LJ. Experimental approaches to evaluation and enhancement of sperm function. In: Jones HW Jr, Jones GS, Hodgen GD, Rosenwaks Z, editors. In Vitro Fertilization: Norfolk. Baltimore, MD: Williams and Wilkins; 1986. pp. 201–214. [Google Scholar]
- 23.Chan PJ, Prough SG, Henig I, Tredway DR. Predictive value of sperm hyperactivation measurements based on the dilution effect method in clinical in vitro fertilization. Int J Fertil. 1992;37:373–377. [PubMed] [Google Scholar]
- 24.Kataoka K, Mizushima T, Ogata Y, Miki T, Sekimizu K. Heat shock-induced DNA relaxation in vitro by DNA gyrase of Escherichia coli in the presence of ATP. J Biol Chem. 1996;271:24806–24810. doi: 10.1074/jbc.271.40.24806. [DOI] [PubMed] [Google Scholar]
- 25.Martin du-Pan RC, Campana A. Physiopathology of spermatogenic arrest. Fertil Steril. 1993;60:937–946. doi: 10.1016/s0015-0282(16)56388-2. [DOI] [PubMed] [Google Scholar]