W. Dianne Smith

Selection of human spermatozoa according to their relative motility and their interaction with zona-free hamster eggs

Human spermatozoa were separated according to their motility by centrifuging semen on discontinuous Percoll gradients. Fractions of the gradients were examined for sperm motility, velocity, viability, morphology, bacteria, and sperm function using the hamster ova sperm penetration assay. The percentage of motile sperm increased from 40% to 60% motile sperm in 60% Percoll to 90% to 100% Percoll. Sperm velocity increased proportionately. Staining showed that greater than 90% of sperm in the 100% Percoll were alive and had normal morphology, and that only sperm cells were found in Percoll concentrations greater than 80%. Sperm isolated in the 80% to 100% Percoll fractions penetrated hamster ova much more frequently than sperm found in the 60% to 70% fractions or than sperm that had not been separated on a Percoll gradient.

Ultrastructural sperm tail defects associated with sperm immotility

Four individuals with a complaint of infertility were evaluated after a semen analysis had demonstrated no motility. The semen analyses were otherwise normal, with the exception of a low count in one subject. All had normal percentages of living sperm. One of the individuals had chronic respiratory disease, and two others had a previous history of genitourinary infection and/or testicular injury. Three subjects possessed antisperm antibodies. Electron microscopy revealed a multiplicity of sperm tail structural defects seen in all specimens. Some of these data support the concept of acquired immotile sperm syndrome(s) with ultrastructural defects, as contrasted with the usual congenital forms of the immotile-cilia syndrome.

Benefits of the sperm (hamster ova) penetration assay in the evaluation of the infertile couple

The males of 310 infertile couples and 30 control couples (current pregnancy) were evaluated with the sperm (hamster ova) penetration assay (SPA) and seminal fluid analysis (SFA). The SPA was found to have a sensitivity of 100% and a specificity of 97% compared to 41% and 90%, respectively, for the SFA. The highest degree of concordance of the two tests existed when both tests were abnormal and no female factor was identified. The poorest concordance occurred when the SFA was normal and no female infertility factor was identified. In almost all cases of unexplained infertility where no female infertility factor was present, the problem could be assigned to the man, as evidenced by an abnormal SPA. The SFA seemed to have some predictive value with respect to the outcome following treatment of the man.

Infertility in mice after unilateral vasectomy**Supported by National Institutes of Health grants R23 HD16608 and P50 HD12629.

The effects of unilateral vasectomy upon fertility and antisperm antibody production were studied using DBA/1J mice. Thirty-six males underwent either unilateral vasectomy, unilateral orchiectomy, or sham surgery. In vivo effects upon fertility were monitored by matings. Antisperm antibody titers were measured monthly. In vitro fertilization was performed in the presence of serum obtained 4 months postoperatively, and serum testosterone levels were also determined. After 3 months, only 1 male in the vasectomy group induced a pregnancy (1 of 12), while all but 1 of the males in the two control groups induced a pregnancy (20 of 21). The geometric mean antisperm antibody titer was 1:169 in the vasectomy group, while the orchiectomy and sham surgery groups had titers of 1:4 and 1:14, respectively (P less than 0.0001). The percentage of eggs fertilized in vitro in the presence of serum from experimental mice fell from 80% in the two control groups to 40% in the unilateral vasectomy group. Unilateral vasectomy induced infertility in DBA/1J mice and an antisperm antibody response. Sera containing these antibodies inhibited in vitro fertilization. This suggests that infertility after unilateral vasectomy may be immunologically mediated by antisperm antibodies.

Laser light-scattering study of the effect of washing on sperm motility**Supported in part by grant HD-12629 to Dr. Wylie I. Lee and grant HD-13075 to Dr. Penelope Gaddum-Rosse, from the National Institutes of Health. Presented in part at the Thirty-Eighth Annual Meeting of The American Fertility Society, March 20 to 24, 1982, Las Vegas, Nevada.

The effect of washing on human sperm motility was measured by means of dynamic laser light-scattering spectroscopy. Semen samples from 24 fertile donors were diluted with Biggers, Whitten and Whittingham (BWW) medium and subsequently centrifuged at one of the following forces: 235 x g, 325 x g, 400 x g, 470 x g, 500 x g, 600 x g, and 800 x g. The duration of centrifugation was 8 minutes for the first wash, 6 minutes for the second wash, and 3 minutes for the third wash. Sperm motility was evaluated in terms of the root mean square swimming speed of the spermatozoa and the mean migration rate of washed spermatozoa in estrous bovine cervical mucus (BCM). It was found that sperm motility and viability were improved when semen samples were washed at 235 x g, even after three washes. However, washing at forces of 600 x g or more reduced sperm motility and also their ability to penetrate cervical mucus in vitro. Repeated washing at forces between 300 x g and 500 x g had little deleterious effect on sperm motility.