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At least 19 recordsLinked to original sources
PubMed1992

A comparison of the frequency and type of chromosomal abnormalities in human sperm after different sperm capacitation conditions.

Human sperm karyotypes can be prepared after fusion of human sperm with Golden hamster oocytes. Most laboratories use one of two methods of sperm capacitation: incubation of freshly-ejaculated sperm in Biggers, Whitten, and Whittingham (BWW) medium for 5-7 h at 37 degrees C or sperm storage in (N-tris [hydroxymethyl]methyl-2-aminoethanesulfonic acid; 2-([2-hydroxy-1,1-bis(hydroxymethyl)ethyl]amino)ethanesulfonic acid) (TES)-Tris yolk buffer (TYB) for 1-3 days at 4 degrees C. Since there have been conflicting reports as to whether there is a difference in the frequency of structural chromosomal abnormalities between BWW capacitation and storage in TYB for 2 days, we analyzed a larger number of karyotypes (8974) from 136 donors to determine if there was any difference in the frequency or type of chromosomal abnormalities in sperm treated by fresh BWW capacitation, storage in TYB for 1 day (TYB-1), or storage in TYB for 2 days (TYB-2). There was no difference in the frequency of numerical chromosomal abnormalities or sex ratio in any of the three treatment groups. However, there was a significantly increased frequency of structural chromosomal abnormalities after storage in TYB-1 and TYB-2. There was no difference in the frequency or type of structural chromosomal abnormalities after sperm storage in TYB-1 compared to TYB-2.

Adult↗
PubMed1992

In vitro sperm capacitation to treat antisperm antibodies bound to the sperm surface.

Our objective was to study antisperm antibody bound to the acrosome region during in vitro capacitation and to determine whether acrosome-antibody free sperm can be obtained from previously acrosome-antibody-coated sperm. The spermatozoa from a selected series of 14 patients were tested for sperm antibodies bound to the sperm surface using d-IBT and focusing on the acrosome positivity. The tests were carried out before the incubation and after 3, 6, 9, and 12 h of incubation in Tyrode's solution with 0.5% human serum albumin as the capacitation medium. Tests to evaluate acrosome region, sperm motion parameters, and zonae binding ability were carried out. In this way we were able to evaluate sperm function during capacitation protocol. The patients were 14 subjects selected according to good seminal characteristics, good post-rise sperm parameters, and high percentage of ASA bound to the sperm surface. In all cases the results showed that antisperm antibodies bound to the acrosome region were shed prior to the acrosome reaction. During sperm capacitation in human a modification, migration, or shedding of plasma membrane molecules takes place. The presence of antibodies in such an important area of the sperm head could certainly interfere in the fertilization process. Our data indicate that in vitro capacitation could provide an in vitro therapy capable of eluting antibodies from the acrosome region.

Acrosome↗
PubMed1992

Effects of modulators of protein kinases and phosphatases on mouse sperm capacitation.

We examined effects of modulators of protein kinases and phosphatases on the kinetics of mouse sperm capacitation. The chlortetracycline fluorescence assay was used to monitor the process of capacitation (in terms of the appearance of the B pattern). The treatment of sperm with dibutyryl cyclic AMP (cAMP) or dibutyryl cGMP resulted in a higher percentage B pattern at various times during capacitation compared with the control. The addition of 100 microM H8 inhibited the cyclic nucleotide-dependent stimulation of capacitation. Tumor promotors, 12-O-tetradecanoyl phorbol 13-acetate (TPA; a stimulator of protein kinase C) and okadaic acid (an inhibitor of protein phosphatases 1 and 2A), induced a rapid appearance of the B pattern (15 min after addition) and maintained a percentage B pattern similar to that of the control in the later period of capacitation. An inhibitor of protein kinase C, staurosporine, inhibited the TPA-dependent acceleration of capacitation. Furthermore, the addition of genistein, an inhibitor of protein tyrosine kinases, resulted in a strong inhibition of capacitation. All agents tested did not affect sperm motility. These data suggest that protein phosphorylation and dephosphorylation may play regulatory roles in mediating mouse sperm capacitation.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1978

Effect of various hexoses on sperm capacitation and penetration of rat eggs in vitro.

Fertilization of rat eggs in vitro could not be achieved when epididymal spermatozoa were preincubated and eggs in clots incubated in a chemically defined medium without D-glucose. Very high proportions (84-100%) of eggs examined were undergoing fertilization when 2.78-8.34 mM-D-glucose were included in the medium. The substitution of D-fructose or D-galactose for D-glucose resulted in very poor penetration rates (0-4%), but D-mannose was effective for fertilization (59-99% penetration). Incubations for sperm capacitation and egg fertilization in different media containing the various hexoses showed that rat epididymal spermatozoa could be partly capacitated without hexose, that D-glucose, D-mannose or D-galactose but not D-fructose is effective for sperm capacitation and that only D-glucose and D-mannose supported penetration of eggs in vitro.

Animals↗
PubMed1979

Is prolactin involved in sperm capacitation?

Immunoreactive prolactin in high concentration was detected in the human semen. Therefore, the effect of prolactin on the various metabolic parameters of the human spermatozoa was studied. It was found that prolactin brought about many of the biochemical changes in the spermatozoa which are known to be associated with the process of capacitation. These results suggest that prolactin has a role in the sperm capacitation.

Acrosome↗
PubMed1992

Ca(2+)-related changes in the mouse sperm capacitation state: a possible role for Ca(2+)-ATPase.

Mammalian spermatozoa require extracellular Ca2+, some of which must be internalized, to undergo complete capacitation. At a critical threshold, a rise in intracellular Ca2+ will trigger acrosomal exocytosis. We used chlortetracycline (CTC) fluorescence patterns to assess changes in the capacitation state of mouse spermatozoa after incubation under various conditions that would affect their intracellular Ca2+ concentrations. Under standard conditions with 1.80 mmol CaCl2l-1 known to support capacitation within 120 min and subsequent fertilization in vitro, a rise in the number of capacitated, acrosome-intact cells (B pattern) was observed over the first 60 min, followed by a decline. A detectable increase in capacitated, acrosome-reacted cells (AR pattern) coincided with the maximum of B pattern cells and a continued rise was observed over the following 60 min. With incubation in 3.60 mmol Ca2+l-1, the rise in AR cells began at 30 min, suggesting that this treatment accelerates capacitation. Introduction of ionophore A23187 at 15 min to cells in standard Ca2+ produced a similar but even more rapid response, with a maximum in B pattern cells and a noticeable rise in AR cells within 10 min. Thus ionophore-treated cells proceed through capacitation, but do so very quickly. However, ionophore in the presence of 90 mumol Ca2+l-1 could promote transition from the uncapacitated F pattern to the capacitated B pattern, but could not trigger acrosomal exocytosis, indicating that the latter requires high extracellular Ca2+. After preincubation in Ca(2+)-deficient medium, most cells exhibited the uncapacitated F pattern and the introduction of millimolar Ca2+ altered this distribution only slowly, over a period of 50 min. In contrast, preincubation in 90 mumol Ca2+l-1 resulted in a minority of F pattern cells and, within 10 min of millimolar Ca2+ introduction, a significant increase in AR cells was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

Trypsinization increases lectin-induced agglutinability of uncapacitated guinea pig sperm.

Capacitated guinea pig sperm are more agglutinable by the lectin soybean agglutinin (SBA) than uncapacitated sperm (Talbot and Franklin, '78). This study demonstrates that uncapacitated guinea pig sperm become as agglutinable by SBA as capacitated sperm when treated with trypsin, but not chymotrypsin. The pattern of lectin induced sperm agglutination after trypsinization resembles that for capacitated sperm. Also, trypsinization specifically increases SBA induced agglutination and does not affect agglutination by RCA-60; similar results are obtained during in vitro capacitation. Taken together, these data may indicate that a trypsin-like enzyme modifies the sperm surface during capacitation.

Agglutination↗