Further indications of the multicomponent nature of the acrosome reaction‐inducing substance of human follicular fluid

Fehl, P.; Miska, W.; Henkel, Ralf

doi:10.1002/mrd.1080420111

Cited by 22 publications

(21 citation statements)

References 43 publications

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“…This study demonstrates that, even though the chemotactic activity of FF is retained after charcoal treatment, the apparent hyperactivation-causing activity is eliminated by this treatment. Since charcoal removes the steroid constituents of FF (including progesterone) [19], it can be concluded that the hyperactivation stimulated by FF is caused by a steroid constituent in the fluid, most likely progesterone. Our results and conclusion are in agreement with those of others [21,32] who found that sperm incubation with FF results in hyperactivation, unlike incubation with charcoal-treated FF or steroid-free plasma medium.…”

Section: Progesterone In Ff Appears To Be the Reason For The Hyperactmentioning

confidence: 99%

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Human Sperm Chemotaxis: Is Progesterone a Chemoattractant?1

Jaiswal¹,

Tur-Kaspa²,

Dor³

et al. 1999

Biology of Reproduction

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Follicular fluid (FF) induces sperm chemotaxis in human spermatozoa. Progesterone also causes sperm accumulation. However, sperm accumulation can be caused by chemotaxis, chemokinesis, and trapping of various kinds. It has been suggested that progesterone also induces chemotaxis in human spermatozoa. In view of the physiological significance of sperm chemotaxis in human fertilization and its potential clinical implications, it is important to determine unequivocally whether chemotaxis is induced by progesterone and, if so, whether progesterone in FF is the chemoattractant. To resolve these questions we looked for characteristic changes in the direction of sperm swimming toward pure progesterone as well as toward FF before and after progesterone removal. Progesterone caused sperm accumulation and hyperactivation-like motility, but it caused very few changes in the direction of sperm swimming that are characteristic of chemotaxis. Removal of progesterone (and other steroids) from FF by charcoal treatment abolished the sperm hyperactivation-like motility but not sperm chemotaxis. These results suggest that while progesterone might be a weak chemoattractant, it is not the major chemoattractant in FF. Progesterone probably causes human sperm accumulation mainly by inducing hyperactivation-like motility and, as a consequence, sperm trapping.

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Section: Progesterone In Ff Appears To Be the Reason For The Hyperactmentioning

confidence: 99%

“…Progesterone as well as other steroids was removed from FF by adding dextran-coated charcoal, essentially as described by Fehl et al [19] with some minor modifications. Briefly, FF (500 l, 10 times diluted with PBS) was incubated with 250 l dextran (0.05%)-coated charcoal (0.5%) for 3 h at 4ЊC with rotation.…”

Section: Progesterone Removal From Ffmentioning

confidence: 99%

Human Sperm Chemotaxis: Is Progesterone a Chemoattractant?1

Jaiswal¹,

Tur-Kaspa²,

Dor³

et al. 1999

Biology of Reproduction

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“…1989), thus being a possible physiological stimulus for the spermatozoon during transit in the female genital tract and at the moment of oocyte fertilization. In the female genital tract, it is found in a protein‐bound form (Fehl et al. 1995).…”

Section: Introductionmentioning

confidence: 99%

Effect of Exogenous Progesterone on Post‐thaw Capacitation and Acrosome Reaction of Bovine Spermatozoa

Lukoševičiūtė¹,

Žilinskas²,

Januškauskas³

2004

Reprod Domestic Animals

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The aim of this work was to study the effect of progesterone (P4) on capacitation and acrosome reaction (AR) of post-thaw bovine spermatozoa in vitro. Spermatozoa were incubated (0-180 min) in capacitation medium supplemented with 0, 0.1, 1.0 and 10.0 microg/ml of P4. At different time intervals aliquots were taken to determine sperm plasma membrane lipid destabilization, or capacitation (AR induced by lysophosphatidylcholine) in spermatozoa. The second experiment aimed to study the effects of P4, as potential inducer of AR in heparin-capacitated spermatozoa. The acrosomal status and viability of spermatozoa were evaluated under an epifluorescence microscope using Ethidium homodimer/peanut agglutinin fluorescein isothiocyanate staining method. Plasma membrane scrambling in spermatozoa was assessed by a flow cytometer, using merocyanine staining. The results show that P4 at the concentrations used had no negative effects on sperm viability. Progesterone significantly enhanced sperm capacitation (p < 0.001), but had no effect on plasma membrane lipid stability (p > 0.05) and did not significantly increase the AR of heparin-capacitated spermatozoa (p > 0.05). Progesterone displayed its effects in a dose-dependent manner with a maximum effect of 10 microg/ml P4 at 180 min of incubation. The results demonstrate that in cryopreserved bovine semen, P4 acts as capacitating, but not as an AR-inducing agent.

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“…Conversely, when spermatozoa are stimulated only with P, higher doses of the steroid (1 mM) are needed to stimulate the low affinity P receptor. Therefore, human acrosome reaction can be induced by micromolar P concentrations (19), but when the steroid is combined with CBG, a solution of CBG þ P at a nanomolar concentration is enough to elicit the AR (20).…”

Section: Figurementioning

confidence: 99%