Movement Characteristics Of Human Spermatozoa Research Articles

Analysis of the lipid content and the motility of human sperm after follicular fluid treatment.

The effect of human follicular fluid (hFF) on the cholesterol and phospholipid content and the movement characteristics of human spermatozoa were studied. Semen was selected by a discontinuous Percoll gradient and incubated during in vitro capacitating conditions with B2 medium supplemented with hFF 20%. Percoll pelleted spermatozoa were incubated in either B2 (B2-Percoll) or B2 supplemented with hFF (hFF-Percoll). In hFF-Percoll, we observed a time-dependent (24 h) decrease in both the cholesterol and phospholipid contents (cholesterol: 10.1 vs. 8.7 nmol 10(-7) spermatozoa; phospholipids: 17.5 vs. 15.7 nmol 10(-7) spermatozoa, P < 0.05). This decrease in cholesterol and phospholipids in human spermatozoa was concomitant with a high straight line velocity, a high progressive motility percentage and an increased value of lateral head displacement without any significant alteration of the spermatozoal membrane. No modification of the cholesterol: phospholipid ratio after 2 and 24 h of incubation in either B2-Percoll (0.61, 0.54) in hFF-Percoll (0.59, 0.63) was observed when compared with original control semen. It is suggested that the decrease in cholesterol and phospholipids in hFF-Percoll may be taken into account for the changes of membrane modification as part of the capacitation process.

Importance of sperm-to-epithelial cell contact for the capacitation of human spermatozoa in fallopian tube epithelial cell cocultures

Objective: To investigate the mechanisms involved in the stimulatory effect of fallopian tube epithelial cell coculture on sperm movement characteristics. Design: Human spermatozoa were cultured with human fallopian tube epithelial cell monolayers. A microporous membrane was used to prevent sperm-to-epithelial cell contact. Sperm movement characteristics were measured at 4 and 24 hours. Setting: University hospital and fertility center. Patient(s): Voluntary donors. Intervention(s): None. Main Outcome Measure(s): Movement characteristics of human spermatozoa. Result(s): Fallopian tube epithelial cell coculture increased sperm motility, curvilinear velocity, amplitude of lateral head displacement, and hyperactivated motility, mainly at 24 hours, compared with controls. These stimulatory effects were inhibited when a microporous membrane prevented cell-to-cell contact between sperm and fallopian tube epithelial cells. Conclusion(s): Physical contact between sperm and epithelial cells in coculture systems seems to be the main factor in stimulating sperm movement characteristics, and this could be the main mechanism of in vivo sperm capacitation.

Superoxide dismutase in human sperm suspensions: Relationship with cellular composition, oxidative stress, and sperm function

Sensitive techniques have been developed for monitoring superoxide dismutase (SOD) activities inhuman sperm preparations. In contradiction to the protective role normally assigned to SOD, populations of defective spermatozoa recovered from the low density region of Percoll gradients were found to have three times more SOD than functionally competent preparations pelleting in high density Percoll. SOD activity was negatively correlated with the movement characteristics of human spermatozoa and their capacity for oocyte fusion, and positively associated with the induction of peroxidative damage. SOD activity was also highly correlated with other markers of the cytoplasmic space, creatine kinase (CK), and glucose-6-phosphate dehydrogenase (G-6-PDH). We conclude that while SOD may play a physiological role in maintaining a balance between O2.- and H202, high levels of this enzyme are associated with impaired sperm function because (a) the human spermatozoon is highly susceptible to the cytotoxic effects of H202, (b) 02- is an important mediator of normal sperm function, and (c) high SOD activities reflect errors in spermatogenesis associated with germ cell exfoliation and the retention of excess residual cytoplasm by the spermatozoa.

Epithelial cell coculture and the induction of sperm capacitation

To investigate the influence of cultured human oviductal epithelial cells on the movement characteristics of human spermatozoa. Human spermatozoa were cultured with monolayers of human epithelial or Vero cells or conditioned media derived from these cell types. The viability and movement characteristics of the cells was subsequently analyzed at 4, 24, and 48 hours. University hospital and Medical Research Council laboratories. Volunteer donors. Movement characteristics of human spermatozoa. The presence of both Vero and oviductal epithelial cells, but not conditioned media, had a general promoting effect on sperm survival, significantly enhancing sperm viability and motility for up to 48 hours of culture. In addition, the presence of oviductal epithelial cells had a specific, significant stimulatory effect on sperm capacitation, enhancing the incidence of hyperactivated motility after 4, 24, and 48 hours of culture. Significantly, this effect was not observed with cocultures containing Vero cells. The coincubation of human spermatozoa with human oviductal epithelial cells provides a convenient system for the induction and analysis of sperm capacitation.

Changes in movement characteristics of human spermatozoa along the length of the epididymis.

It has been established in laboratory mammals that sperm motility and fertilizing capacity develop during epididymal transit, but sperm maturation along the human epididymis is less well characterized. Spermatozoa were prepared from 5 regions of 8 epididymides from 8 prostatic carcinoma patients undergoing castration and from 8 epididymal spermatocoeles located adjacent to the head of the epididymides and the testes of 5 patients. Sperm movement was characterized by computer-aided sperm analysis (CASA), and percentage motility was estimated by conventional methods. The efferent ducts and spermatocoeles contained the same percentage of motile spermatozoa with similar kinematics. Percentage motility increased from 22.9 +/- 4.8 (mean +/- SEM) in the efferent ducts to a maximum of 68.3 +/- 7.9 in either the mid- or distal corpus epididymidis and declined in the cauda region. Straight line velocity increased from 20.3 +/- 3.7 microns/sec to reach a plateau value of 44.0 +/- 5.3 microns/sec in the mid-corpus epididymidis; this was more marked than the increase in curvilinear velocity, although the trend was the same. Similar trends in linearity and straightness of the swim paths were not accompanied by any significant changes in the amplitude of lateral head displacement. This objective quantification of sperm movement documents the maturation of sperm motility in the human epididymis, confirming that this maturation pattern is similar to that in other mammals.

Pentoxifylline stimulates hyperactivation in human spermatozoa

The effects of pentoxifylline on the movement characteristics of human spermatozoa incubated under capacitating conditions were examined using automated digital image analysis. Washed spermatozoa from cryopreserved and fresh normozoospermic, and fresh oligozoospermic semen were incubated in the presence of pentoxifylline (3.6 mM) for 30 min. In each group, pentoxifylline caused an increase in the average lateral head displacement and curvilinear velocity and a decrease in the linearity of progression. This related to a significant increase in the population of spermatozoa developing hyperactivation. The effect was maximal at between 15 and 75 min incubation. No detrimental effect on sperm vitality was demonstrated. It was shown that hyperactivation remained elevated compared with the control after washing pentoxifylline from the suspension. This effect was maintained for 1 h, but became insignificant after 3 h. These data demonstrate that pentoxifylline stimulates the development of hyperactivation in washed human spermatozoa, a phenomenon which may be of value in the treatment of some forms of male factor infertility.

Treatment of human spermatozoa with follicular fluid can influence lipid content and motility during in vitro capacitation

In order to evaluate the role of human follicular fluid (HFF) on the fertilizing capacity of spermatozoa, we studied the effect of HFF on the lipid composition and on the movement characteristics of human spermatozoa. Spermatozoa (spz) from normospermic patients were prepared with a discontinuous Percoll gradient and incubated in Ménézo B2 medium with or without a supplement of 20% HFF (HFF-Percoll spz and B2-Percoll spz respectively) for 2 and 24 h. After 2 h HFF incubation, percentage progressive motility, straight line velocity (VSL), and amplitude of lateral head displacement (ALH) were improved in HFF-Percoll spz as compared to B2-Percoll spz (P < or = 0.05). After a longer incubation period (24 h), lipid changes appeared in HFF-Percoll spz with lower levels of cholesterol (P = 0.02) and phospholipids (P = 0.05). No modification of the cholesterol/phospholipid ratio after 2 and 24 h of incubation in either B2-Percoll spz or HFF-Percoll spz was observed. Such decreases in lipid content of HFF-Percoll spz may be factors which could be taken into account as constituting part of membrane modifications during the capacitation process.

Effect of the human cumulus oophorus on movement characteristics of human capacitated spermatozoa

The effect of human cumulus oophorus on movement characteristics of human spermatozoa previously incubated in vitro under capacitating conditions was studied using automated digital image analysis. When spermatozoa were incubated for a short time with whole cumuli, most of those that penetrated the cumulus intercellular matrix were characterized by a linear movement with small amplitudes of lateral head displacement, but with elevated values of beat cross frequency. Short (5 min) incubation with solubilized cumulus intercellular matrix of spermatozoa preincubated in capacitating conditions (6 h) significantly reduced the percentage of spermatozoa showing the 'hyperactivated' type of motility characterized by high curvilinear velocity, low progressive velocity and elevated values of lateral head displacement. Moreover, a subpopulation of spermatozoa with very high values of progressive velocity and beat cross frequency and with reduced amplitudes of lateral head displacement appeared in these conditions. This cumulus-related motility pattern was not seen in fresh spermatozoa or in those incubated in the absence of cumulus material. Changes in the sperm movement characteristics similar to those observed in the presence of the solubilized cumulus matrix could also be induced by some of its h.p.l.c. fractions. These results show that the intercellular matrix of the human cumulus oophorus exerts a specific effect on human sperm motility, probably acting preferentially on the 'hyperactivated' sperm subpopulation.

Transmembrane migration technique: Reexamination of its usefulness in sperm motility assessments

A study was carried out using time-exposure photomicrography to investigate the potential usefulness of the transmembrane migration technique in the assessment of drug effects on human sperm motility. Significant but weak correlations were evident between the transmembrane migration ratio (TMMR%) and both % motility ( r = 0.43; p < 0.05) and the amplitude of lateral sperm head displacement ( r = 0.40; p < 0.05). However, no significant correlations were evident between TMMR% and the concentration of motile spermatozoa, mean path velocity, or frequency of sperm head rotation. Exposure to 2.5 mM 2-deoxyadenosine caused significant increases in % motility, mean path velocity, and frequency of sperm head rotation, with no concomitant rise in TMMR%, while 5.0 mM caffeine caused significant elevations in both TMMR% and in % motile cells. It is concluded that the transmembrane migration technique is a relatively insensitive method for detecting subtle but important changes in the movement characteristics of human spermatozoa.

Changes in the motility pattern of human spermatozoa during in vitro incubation.

Suspensions of capacitating human spermatozoa were analyzed for movement characteristics using high-speed videomicrography. The status of the acrosome reaction was also assessed by the zona-free hamster ova penetration test. (1) Movement characteristics of human spermatozoa were classified into 4 types (A, B, C, D). Type A: The movement was active, but its progressive orientation was irregular. Type B: The spermatozoa moved with a wide amplitude of the end of tail. Type C: The amplitude of the tail decreased, and the linear velocity of progression increased. Type D: The whole part of tail showed wavelike rhythmical movements, and the velocity more increased. (2) Movement characteristics of human spermatozoa in vitro gradually changed from Type A to B, C and D. As the spermatozoa classified Type D moved very powerfully and this motility pattern was obviously different from the other types, it was considered hyperactivation of human spermatozoa. The Type D was found from 2 or 3 hr of incubation, and after 3 or 4 hr most of the spermatozoa showed Type D. (3) The motility pattern of human spermatozoa changed to the Type D before the spermatozoa penetrate into zona-free hamster oocytes. It suggested that the hyperactivation occurred before the acrosome reaction takes place.

Relationship between the movement characteristics of human spermatozoa and their ability to penetrate cervical mucus and zona-free hamster oocytes.

In a group of normospermic donors exhibiting hamster oocyte penetration scores of 0-100%, multiple regression analysis indicated that only 20% of the variation in fertilizing potential could be explained by differences in the movement characteristics of the spermatozoa following incubation in vitro. When the movement characteristics of the spermatozoa in semen were considered this figure was reduced to 6.8% as a result of significant differences in the motility patterns exhibited by the seminal and post-incubation sperm populations. A much closer relationship was observed between the movement characteristics of human spermatozoa in semen and their ability to penetrate cervical mucus. When differences in motile sperm densities were taken into account, 76% of the variation in cervical mucus penetration could be accounted for by the existence of linear correlations with certain aspects of sperm movement (multiple R = 0.874). Of the various attributes of sperm motility measured (linear velocity of progression, frequency of rotation, amplitude of sperm head displacement, % rolling and % yawing), a failure to exhibit an adequate amplitude of lateral sperm head displacement was consistently found to be the most significant factor determining the success of sperm-cervical mucus interaction (R2 = 0.53).

Differences in the movement of morphologically normal and abnormal human seminal spermatozoa.

Movement characteristics of human spermatozoa in fresh semen from 7 fertile men were studied using high-speed cinemicrography. Parameters that measured sperm swimming speed, flagellar beat frequency, flagellar beat shape, and the straightness of the swimming trajectory were obtained from frame-by-frame analysis of the cine films. In addition, each spermatozoon sampled for movement was also classified as being morphologically normal or abnormal, the latter being subdivided into the categories amorphous head, amorphous midpiece, elongated tapering head, piriform tapering head, megalocephalic and microcephalic. The morphological classification procedure involved direct reference of the sperm image on the screen of the cine film analysis console to metric morphological standards. Statistical analysis of the data investigated whether spermatozoa of different morphological types, as well as from different men, exhibited similar or dissimilar movement characteristics. It was found that morphologically normal spermatozoa swam faster and straighter, and exhibited higher beat frequencies than did morphologically abnormal sperm. These distinctions were most pronounced for spermatozoa with elongated or piriform tapering heads or amorphous midpieces.

Movement characteristics of human spermatozoa analysed from kinemicrographs

Motility characteristics of human spermatozoa have been analysed by modern research film methods and compared with visual motility ratings. Spatial distributions and fluctuations of sperm numbers in small subfields deviated significantly from the expected Poisson distribution. Agreement between visual motility estimations and measurements was poor (r = 0.76, explaining only 57% of the variance) with large scatter, whereas there was no difference between highly experienced observers and greenhorns. It is concluded that improvement of visual estimation results by standardisation, training and experience is no attainable goal. There was a significant influence of the sample image on the visual ratings of all observers. Three main groups of tracks can be distinguished: Type I: normal, mainly progressive movement with nearly rectilinear resultant and small lateral head displacements; Type 2: mainly progressive movement, resultant rectilinear or the projection of a helix; sometimes irregular changes of direction; generally large lateral head displacements; Type 3: mainly yawing, circular and helical tracks (pathological movements resulting from impaired midpiece function). In the combined Types 2+3 visual motility ratings are significantly influenced by the mean velocity of the spermatozoa. It is generally concluded that visual motility estimations should be totally abandoned and replaced by objective measuring methods. Where no photoelectrical and electronical methods are available three alternative simple quantitative methods are advocated.