Human and Bovine Sperm Migration

Transcription

1 Human and Bovine Sperm Migration K. S. MOGHSS, M.D. SPERM MGRATON may be accomplished by intrinsic sperm activity, uterotubal contractions, ciliary motions of tubal epithelium, or a combination of these factors. There have been conflicting reports of the relative importance of active sperm migration versus passive transport. 1, 2, 6, 14 ntrinsic motility may be assumed to be responsible for sperm migration in vivo if sperm cells were to ascend through the extirpated uterus and fallopian tubes, deprived of neurologic and hormonal influences. The purpose of this report is to present our findings on sperm migration in isolated human and bovine reproductive tract. MATERAL AND METHODS Human uteri were obtained from fertile women with preinvasive cancer of the cervix or uterine prolapse. Operation was usually carried out during midcycle. Those with gross uterine and/or adnexal disease were excluded. Abdominal hysterectomies and salpingectomies were performed without clamps and with the suture-ligature technique, to avoid damage to the specimens. Some uteri were removed vaginally without the uterine tubes. Each specimen was immersed immediately in normal saline at room temperature. All experiments were initiated within 30 min. after operation. Human midcycle cervical mucus was obtained either from the patient prior to hysterectomy or from healthy fertile young women, and refrigerated until used. Human semen was donated by healthy fertile men whose sperm count and analysis were normal. Bovine uteri with attached vaginas, tubes, and ovaries were removed From the Department of Gynecology and Obstetrics, Wayne State University School of Medicine, Detroit General Hospital, and Hutzel (Woman's) Hospital, Detroit, Mich. Supported in part by Grant AM from the U. S. Public Health Service. Presented at the 23rd Annual Meeting of The American Fertility Society, Washington, D. C., Apr , Bovine estrous cervical mucus and bull semen were kindly supplied by Dr. H. Hafs, Michigan State University. 118

2 VOL. 19, No.1, 1968 SPERM MGRATON 119 intact from freshly slaughtered cows. They were placed in saline and taken to the laboratory for immediate study. A few uteri were obtained from estrous cows. Bovine estrus cervical mucus was collected from animals in heat. Preserved bull sperm was received from Michigan State University. Freshly removed human and bovine uteri were enveloped in moist saline sponges. The cervix was placed in a small beaker filled with recently collected semen (Fig. 1). The uterus was positioned at 45 from the Fig. 1. Schematic drawing of excised human reproductive tract prepared for sperm migration. Normal saline or 5% dextrose --semen horizontal. The entire system was kept at 38 C. in an incubator. The covering sponges were constantly moistened during the experiment. Previous methods for sampling the uterine cavityl. 11 resulted in contamination from the endocervix. This was avoided when samples were obtained through an incision in the uterine fundus. The uterine content was examined for the presence of sperm every hour for 4 hr., at 4-hr. intervals for the next 8 hr., and again after 18 hr. The uterine cavity was opened and washed with normal saline at the termination of each experiment. All samples and washings were screened for sperm. n some human and all bovine experiments, the fimbriated end of the uterine tubes was immersed in normal saline or 5% dextrose solutions (Fig. 1). These solutions were also examined for sperm each time samples were taken from the endometrial cavity. RESULTS No sperm cell was found in the cervical canal, uterine cavity, or uterine tubes during several initial human experiments. Washing the entire tract with a solution of normal saline, 5% dextrose in water, or Ringer's solution did not enhance sperm migration. Similar re

3 120 MOGllSS FEHTLTY & STEHLTY suts were observed in duplicate experiments using estrus and non-estrus bovine specimens. n other studies, the cervical canal was filled with midcycle cervical mucus. The passage of sperm was then tested as described before. Motile sperm were found in the mucus of the cervical canal in human and bovine systems, but none was observed above the cervix. rrigation with physiological solutions did not alter these results. No sperm was recovered from the uterus or fimbriated end of the tubes in 4 human specimens with mucus in the cervical canal or 2 bovine estrus and 2 nonestrus specimens (Table 1). DSCUSSON AND CONCLUSON Van Leeuwenhoek's discovery of motile spermatozoa led to the conclusion that their migration was due to their own propellant activity. 8 However, numerous animal and human experiments suggest that other factors are involved.1, 3, 5, 6, 10, 13-15, 17 Sperm migration in experimental animals is quite rapid and greater than that which may be attributed to intrinsic motility alone.3, 6, 10, 15 Furthermore, nonmotile sperm cells are transported at a comparable rate. 1O,16 Van Demark et al. found that sperm are transported from the cervix to the distal portion of bovine oviducts in less than 2 min.15, 16 They also observed that various stimuli of natural mating or artificial insemination resulted in the release of oxytocin and increased uterine activity.15 Similar patterns of uterine motility were produced in the excised and perfused bovine uterus by the addition of oxytocin to the perfusate.15 Sperm transport was also induced by adding oxytocin to the perfusate after deposition of semen in the cervix. Rubenstein et al. detected spermatozoa at the fimbriae of the uterine tubes within 30 min. after coitus. Von Khreninger-Guggenberger found TABLE 1. Experimental Findings on Sperm Migration in Excised Human and Bovine Reproductive Tract Sperm recovered Mucus in cervical Uterine Specimen No. canal Cervix cavity Tubes Human uterus 2 No No No Human uterus, tubes 4 YeR Yes No No Human uterus 2 Yes Yes No No Bovine tract 2 Yes Yes No No Bovine tract (estrus) 2 Yes Yes No No

4 VOL. 19, No.1, 1968 SPERM MGRATON 121 sperm in an excised human uterus 6 hr. after semen was placed at the external os. Brown recovered sperm from the end of the uterine tubes 68 min. after semen was deposited in the cervix. Bickers simultaneously recorded uterine contractions and aspirated the fundus of the uterus after coitus in a young oophorectomized woman. He was unable to recover sperm in the absence of uterine contractions. Estrogen administration was followed by uterine contraction. Sperm were then found in the uterine cavity after coitus. Transport of the particulate matter through the reproductive tract has been reported by some investigators. 4 5 Others have been unable to confirm these findings Aspiration of sperm from the cul-de-sac or through the cervix may result from contamination of the aspirant with vaginal contents; this may take place even after meticulous precautions. This complication occurred early in our studies when the cervical route was used for sampling uterine contents, and led us to the erroneous conclusion that the few sperm found in the uterine cavity had migrated there. When this approach was abandoned and samples from the endometrial cavity were obtained through an incision in the fundus, no sperm were found. These data conform with the experimental findings of Van Demark and Hays in the COW. 15 However, they are at variance with other observations in the human. Absence of sperm migration in the excised reproductive tract deprived of hormonal and neurological effects supports the contention that sperm do not reach the oviduct solely by means of their intrinsic motility. Recovery of sperm from the en do cervix and as high as the internal os suggests that sperm cells may penetrate the length of the cervical canal unaided if the cervical mucus is favorable.!) An extirpated uterus is not entirely comparable to the intact genital tract, where other factors may affect sperm transport. Postoperative cellular anoxia and degeneration may alter sperm migration even when experiments are carried out promptly. Our observations and those of others suggest that the female genital tract is not an adynamic tube through which sperm can travel independently. Sperm migration through the cervix may depend on innate motility while their ascent through the uterine cavity and fallopian tubes requires extrinsic support. SUMMARY Sperm migration in excised human and bovine genital tract was studied. When the cervix contained suitable midcycle mucus, sperm migrated through the cervical canal but not beyond the internal os. No sperm was

5 12~ MOGHSS FERTLTY & STERLTY recovered from the uterus or the tubes in 4 human specimens with mucus in the cervical canal or 2 estrus and 2 nonestrus bovine specimens. Wayne State University School of Medicine 1400 Chrysler Freeway Detroit, Mich REFERENCES 1. BCKERS, W. Sperm migration and uterine contractions. Fertil Sterilll:286, BROWN, R. L. Rate of transport of sperm in a human uterus and tubes. Arner ] Obstet Gynec 47:407, CARLTON, H. M., and FLOREY, H. Birth control studies.. On the ingress of semen into the uterus during coitus. ] Obstet Gynaec Brit Ernp 38:550, EGL, G. E., and NEWTON, M. The transport of carbon particles in the human female reproductive system. Fertil Steril12: 151, ENGELHORN, E. Cited by Hartman.6 6. HARTMAN, C. G. How do sperm get into the uterus? Fertil Steril8:403, VON KHRENNGER-GUGGENBERGER, J. Experimentelle Untersuchunger uber die verti Kale Spermien Wanderung. Arch Gynak 153:64, KRSTELLER, S. Beitrogezur den Bedingungen der Conception Klim. Wehunschr 8:315, MOGDSS, K. S., DABSH, D., LEVNE, J., and NEUHAUS, O. W. Mechanism of sperm migration. Fertil Steril15:15, PARKER, G. H. The passage of the spermatozoa and ova through the oviducts of the rabbit. Proc Soc Exp Biol Med 27:826, RUBENSTEN, B. R., STRAUSS, H., LAZARUS, M., and HANKN, H. Sperm survival in women. Fertil Steril 2:15, STURGS, S. H. The effect of ciliary current in sperm progress in excised human fallopian tubes. Trans Soc Study Steril 3:31, VANDEMARK, N. L. Spermatozoa in the female genital tract. nt ] Fertil 3:220, VANDEMARK, N. L., and HAYS, R. L. Sperm transport in the genital tract of the cow. Arner ] Physiol183:510, VANDEMARK, N. L., and HAYS, R. L. Rapid spelm transport in the cow. Fertil Steril 5: 131, VANDEMARK, N. L., and MOELLER, A. N. Speed of spermatozoa transport in reproductive tract of estrous cow. ArnerJ Physiol165:674, WALTON, A. On the function of the rabbit cervix during coitus. ] Obstet Gynaec Brit Ernp 37:92, 1930.