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1.
To evaluate the possible effect of pentoxifylline on the acrosomereaction (AR) and its correlation with in-vitro fertilization(IVF), sperm samples obtained from 51 patients who underwentIVF treatment were studied. Acrosome reactions were evaluatedas spontaneous, pentoxifylline-treated and calcium ionophore(A23187) induced, before and after treatment. The correlationof AR with fertilization in vitro in spermatozoa pre-treatedwith pentoxifylline was sought. In cases with failure or verylow fertilization rate (10%) in their previous trials, spermatozoaafter swim-up were treated before insemination. Spontaneousacrosome loss remained low even after treatment (mean ±SD: 8.18 ± 1.74%). Response to A23187 was enhanced significantly(P < 0.001) by pre-treatment with pentoxifylline in 33 controlcases (group A) in which fertilization in vitro was previouslysuccessful without this treatment. Patients with at least twoepisodes of failed fertilization were divided into two groups.In 11 cases (group B), the IVF rate was improved significantly(P < 0.001) by the treatment. This was not observed in sevencases (group C) in which the treatment induced no increase inIVF rate. We achieved nine (27.3%) pregnancies in group A andfive (45.4%) pregnancies in group B. This study demonstratedthat pentoxifylline enhanced A23187 induced the acrosome reactionand this effect was correlated with improvement in IVF rate.  相似文献   

2.
This study was designed to assess the relationship between IVFoutcome and the results obtained with two modified versionsof the zona-free hamster oocyte penetration test in which thespermatozoa were pre-incubated with either hyperosmotic mediumor the divalent cation ionophore A23187. When the former systemwas used, a poor correlation with IVF outcome was observed.Samples screened prior to IVF exhibited a 60% false negativerate (failed penetration test, successful IVF), while for thoseassessed concurrently with IVF, the equivalent figure was 85.7%.Addition of A23187 optimized the penetration system giving higherlevels of sperm-oocyte fusion and a more accurate predictionof the capacity of the spermatozoa to fertilize human ova invitro. With this system the false negative rate was 4.3% forscreened samples and 0% for those assessed simultaneously withIVF. These results suggest that the A23187-enhanced system maybe of value as a screening criterion for IVF.  相似文献   

3.
We have established a monoclonal antibody (mAb) AG7 defininga sperm acrosome antigen-1 (SAA-1) on spermatozoa from the humanand several mammalian species. MAb AG7 inhibits fertilizationof mouse eggs in vitro and in vivo. An important characteristicof mAb AG7 is its inhibition of the rise in intracellular calciuminduced by progesterone in human spermatozoa. Here we show that,following the acrosome reaction, SAA-1 is lost from the capof human spermatozoa but remains detectable in the equatorialregion. Acrosome reaction assays demonstrated a clear differencebetween progesterone- and A23187-induced acrosome reactions.For induction of the acrosome reaction with progesterone, aminimum capacitation time of 6 h was required. A23187 inducedthe acrosome reaction regardless of capacitation time. MAb AG7completely inhibited the progesterone-induced acrosome reaction,but not the A23187-induced acrosome reaction in human spermatozoa.Differences in the pattern of calcium flux induced by the twoagents might account for this phenomenon. The inhibition ofthe progesterone-induced acrosome reaction by mAb AG7 impliesa regulatory function of SAA-1 during the human sperm acrosomereaction.  相似文献   

4.
The effect of peritoneal fluid (PF) from endometriosis patientswas studied in spontaneous and stimulus-induced (Ca-ionophore;A23187) acrosome reactions. PF samples were obtained from 21infertile women with endometriosis and five normal women (controls).Sperm acrosomes were examined by staining with Pisum sativumagglutinin labelled with fluorescein isothiocyanate. The incidenceof spontaneous acrosome reaction after 1 and 6 h of incubation(6.7 ± 1.6 and 6.9 ± 1.4 respectively) was significantly(P < 0.001) lower when the incubation was performed withPF from endometriosis patients in comparison with spermatozoaincubated in PF from the control group (12.8 ± 1.1 and12.8 ± 0.8). Similarly, the incidence of A23187-inducedacrosome reaction after 1 and 6 h of incubation (19.8 ±2.7 and 20.0 ± 2.4) was significantly (P < 0.001)lower when spermatozoa were incubated with PF from endometriosispatients in comparison with spermatozoa incubated with PF fromthe control group (34.6 ± 9.8 and 34.4 ± 1.1).The incidence of A23187-inducible acrosome reaction was alsosignificantly (P < 0.001) lower when the incubation was performedwith PF from endometriosis patients (13.1 ± 2.8 and 13.1± 2.4) when compared with that from the control group(21.8 ± 2.6 and 21.6 ± 1.5). No relationship wasfound between the stage of endometriosis and the incidence ofacrosome loss. In conclusion, the PF from endometriosis patientsdecreased both spontaneous and stimulus-induced acrosome reaction.This may represent a mechanism for the detrimental effect ofthe PF from endometriosis patients on the spermatozoa-oocyteinteraction and partially explain the aetiology of infertilityin patients with endometriosis.  相似文献   

5.
The osmo-sensitivity of the human sperm acrosome reaction wasinvestigated by determining the effect of hyper- and hypo-osmolalconditions on the ionophore A23187- and dbcAMP-induced reactionof both capacitated and non-capacitated spermatozoa. Hyper-osmolalconditions inhibited the agonist-induced reactions of both typesof spermatozoa. Hypo-osmolal conditions caused a spontaneousloss of acrosomes from capacitated but not from non-capacitatedspermatozoa. The loss of acrosomes under hypo-osmolal conditionswas further enhanced by dbcAMP but not by ionophore A23187.Although significant decreases in sperm viability were occasionallyobserved at the high and low osmolalities, these decreases werenot consistent and could not account for the observed loss ofacrosomes. It is concluded that the human sperm acrosome reactionis osmo-sensitive. The acrosome reaction stimulated by ionophoreA23187 (raises intracellular Ca2+) and dbcAMP (activates proteinkinase A which causes protein phosphorylation) appears to involvewater entry downstream from the action of these agonists. Preincubationin albumin (capacitation) causes human spermatozoa to lose theiracrosomes under hypo-osmolal conditions. Finally, capacitationis not an essential prerequisite to the acrosome reaction aslong as agonists are used that by-pass certain membrane-relatedevents.  相似文献   

6.
Spermatozoa were recovered form three regions of the epididymisof six prostatic carcinoma patients. After washing and incubatingfor 3 h in Ham's F-10 medium, with or without 5 µM A23187for the last 30 min, spermatozoa were tested for vitality byhypotonic swelling and permeated with methanol to detect theacrosome with peanut agglutinin. Whereas the extent of spontaneousacrosome reactions was similar for spermatozoa from all regionsof the duct, 17 and 28% of spermatozoa from all regions of theduct, 17 and 28% of spermatozoa from the corpus and cauda epididymidisrespectively, responded to stimulation by A23187 with acrosomereactions but there was no stimulation by A23187 of spermatozoafrom the efferent ducts. The percentage of morphologically normalspermatozoa increased stepwise towards the distal regions, withabnormalities being mostly enlarged heads in more proximal regions:they were largely absent form the cauda epididymidis. Spermhead swelling was similarly observed in cynomolgus monkey spermatozoafrom the caput epididymidis but not the more distal regions.These forms were not observed when spermatozoa were fixed beforesmearing, indicating that they were artefacts of sperm preparation.The changes in the susceptibility of non-fixed epididymal spermatozoato produce morphological artefacts and the gain in their acrosomalresponse to ionophore demonstrate maturational changes of spermatozoain the human epididymis.  相似文献   

7.
This study was designed to compare three different fluorescentprobes to assay the acrosome reaction in human spermatozoa:chlortetracycline (CTC), mannosylated bovine serum albumin (BSA)labelled with fluorescein (MAF), and quinacrine (QN)- Normalhuman sperm ejaculates were washed and allowed to swim up for30–60 min. Samples were examined under epifluorescencefor the percentage of the acrosome reacted spermatozoa, as detectedby the three probes. There was no significant difference betweensamples of fresh, uncapadtated spermatozoa evaluated with CTC,MAF or QN; all gave <10% reacted. Following capacitationfor 3 h, the percentage of spontaneously reacted spermatozoawas higher than in fresh spermatozoa; CTC and MAF gave the samepercentage (12%), while QN indicated a higher percentage (18%)of reacted spermatozoa (P < 0.001). Following exposure toionophore A23187 at 1 h, the percentage of acrosome reactionsincreased to a mean of 31% as detected with CTC or MAF; themean percentage (45%) was significantly higher with QN (P <0.0001). Further incubation up to 2 h with A23187 did not changethese percentages. These results suggest that the QN probe detectsthe onset stage of the acrosome reaction, whereas the CTC andMAF probes detect the later stages in which the acrosomal capis lost. Use of the two types of probe provides a means forfiner resolution of the time course of the acrosome reactionin the human spermatozoa.  相似文献   

8.
This study has examined the extent to which the informationgenerated by ionophore-enhanced bioassays of the acrosome reactionand sperm-oocyte fusion might be predicted from the computer-aidedanalysis of sperm motility Strong correlations (r 0.7) wereobserved between specific components of sperm movement in semenand the potential for A23187-induced sperm-oocyte fusion, generatinga stepwise regression coefficient of R = 0.663 on the basisof two criteria, percentage progressive motility and amplitudeof sperm lateral head displacement (ALH). The movement characteristicsof the spermatozoa recovered from the Percoll gradients gavean even higher R value of 0.838 on the basis of four variables(percentage rapid, average path velocity, straightness and ALH).In contrast, the ability of human spermatozoa to undergo acrosomereaction in response to A23187 exhibited a limited correlationwith sperm movement, whether these measurements were made inthe original semen sample or following Percoll purification(R 0.4). These results have diagnostic implications, sincesperm-oocyte fusion and the acrosome reaction clearly differin their relative dependence on sperm motility. In practicalterms, it should be noted that the computer-aided analysis ofsperm movement was shown to provide up to 70% of the informationgenerated by the more laboured assessment of sperm-oocyte fusion.  相似文献   

9.
The acrosome reaction in boar spermatozoa   总被引:1,自引:0,他引:1  
In order to gain more insight into the molecular alterationsof the acrosome, boar spermatozoa were incubated in a calcium-containingmedium in the presence of the lonophore A23187. The time-courseof the acrosome reaction was assessed by phase-contrast microscopy.Different stages of the acrosome reaction were studied by immunoelectronmicroscopy using a specific antibody directed against the completeouter acrosomal membrane. The introduction of monoclonal antibodiesgenerated by immunization of Balb/c mice with the isolated outeracrosomal membrane permitted a study of the topography of distinctmembrane proteins during the acrosome reaction. The exposureof activation of a fucose-binding protein important for sperm—zonaattachment was studied using neo-glycoproteins labelled withcolloidal gold for transmission electron microscopy.  相似文献   

10.
Motile human sperm populations were prepared from liquefiedsemen (5 donors x 3 replicates) using Percoll gradients at 30–60 min post-ejaculation and preincubated in a complex ‘syntheitictubal fluid’ culture medium (STF) at 37° C under 5%CO2 in air for 6h. Aliquots of these suspensions were then incubatedfor a further 2 h in STF containing 0, 5, 25, 50, 75 and 100%(v/v) pooled human follicular fluid (FF). Another aliquot wastreated with 10 µm A23187 in STF for 20min and then incubatedin fresh STF medium for a futher 2h to induce maximal acrosomeloss. Acrosome reactions were assessed using both the triple-staintechnique and fluorescent peanut agglutinin lectin-labelling.Sperm motility and movement characteristics were assessed fromvideorecordings using digital image analysis (CellSoft). Exposureto FF caused only relatively small proportions of the preincubatedspermatozoa to undergo acrosome reactions. The size of theseresponsive sub-populations was smaller than that capable ofresponding to a Ca2+ influx generated by A23187. Increased FFconcentrations induced a progressive loss of motility and trendsfor changes in movement characteristics that may have been relatedto reduced intracellular Ca2+. This interpretation of theseobervations is that while FF may act to stimulate or promotethe human sperm acrosome reaction it does not appear to be aspecific inducer of it. Consequently, a precise role for FFat the relatively low concentrations that would be expectedto be present in the tubal ampulla in the physiological regulationof human fertilization remains unproven  相似文献   

11.
The study was designed to investigate the effects of pentoxifyllineon the acrosome reaction of human spermatozoa in vitro, andto determine whether the reaction is differently modulated aftersperm selection by multiple tube swim-up and Percoll buoyantdensity centrifugation. The acrosome reaction was induced invitro by using calcium ionophore (A23187) and was detected bymeasuring the fluorescence of FITC-conjugated goat anti-mouseimmunoglobulin bound to CD46 antibody (which binds to the CD46receptor site on the inner acrosomal membrane) by flow cytometry.Spermatozoa separated on Percoll displayed significantly lowerspontaneous acrosome reactions (P= 0.002) than did those separatedby the swim-up technique. Pentoxifylline did not, by itself,induse acrosome reaction, but after induction with ionophore,it significantly increased the reaction (P= 0.0003) and thisincrease was seen to be greater when Percoll separation wasused as compared to the swim-up technique (P= 0.0002). We thereforeconclude that percoll selection of motile spermatozoa togetherwith pentoxifylline treatment may be of value in assisted reproductivetechniques, as an increased ARIC score arouse after both treatments,and that flow cytometry allows a precise and rapid quantificationof the acrosome reaction.  相似文献   

12.
We have recently reported, in a small cohort of subjects, thatacrosome reaction (AR) and intracellular free calcium ([Ca2+]i)increase in response to progesterone were significantly correlatedwith in-vitro fertilization (IVF) rate. In the present studywe extended these results to 90 subjects undergoing IVF. Weconfirm that both parameters were highly significantly correlatedwith the fertilization rate (P<0.001). In particular, significantlylower responses to progesterone were detected in subjects witha fertilization rate <50%, further enlightening the functionalsignificance of sperm responsiveness to progesterone with respectto the process of fertilization. Moreover, we report here thatboth tests are highly discriminant of fertilization success,with positive predictive values >90% for [Ca2+]i values whichincrease by >1.2-fold and AR inducibility >7% (cutoffvalues). Conversely, AR following challenge with the calciumionophore A23187 was less significantly correlated with thepercentage fertilization rate (P<0.05), and showed lowerpredictive values than response to progesterone. All these tests([Ca2+]i increase in response to progesterone, AR in responseto progesterone and to A23187) appear highly sensitive and moderatelyspecific The positive predictive value may rise to >95% whenthe combination of two tests ([Ca2+]i and inducibility of ARin response to progesterone) is considered. No correlation withfertilization rate has been found for spontaneous AR or basal[Ca2+]i. In conclusion, we propose that assessment of humansperm responsiveness to progesterone may be clinically usefulin predicting fertilizing ability in vitro.  相似文献   

13.
Smoking and varicocele are frequent findings in the medicalhistory and physical examination of patients attending and rologicaloutpatient departments. However, data about their influenceon human semen parameters, such as sperm concentration and motility,are contradictory. Therefore, the purpose of this study wasto examine sperm function (acrosin activity and induction ofthe acrosome reaction) in smokers (n = 130) and varicocele patients(n = 30)compared with normal fertile donors (n = 20). The acrosomereaction was detected by triple staining after 3 h ofincubationat 37°C, followed by treatment with 0.1%dimethyl sulphoxide(spontaneous acrosome reaction) and 10 µM calcium ionophoreA23187 (induced acrosome reaction) for 1 h at 37°C. Acrosinactivity was measured by gelatinolysis. The diameters aroundthe sperm heads after gelatinolysis and the percentages of spermatozoashowinghalo formations were evaluated. The inducibility of theacrosome reaction was significantly lower in semen samples fromsmokers than in those from the fertile group (7.1 ±3.2versus 11.2 ± 4.0%, P < 0.01), whereas no statisticallysignificant difference was demonstrated in spermatozoa frompatients with varicocele (9.3 ± 4.3%). Both the percentagesof spermatozoa with halo formation (53.3 ±20.0 versus76.6 ± 13.6%, P < 0.05) and the halo diameters (16.1± 6.6 versus 31.0 ± 14.5 urn, P < 0.001) weresignificantly lower in the varicocele group than in thesamplesfrom fertile men. These data suggest that smoking and varicoceleaffect sperm function, and that the standard semen parametersalone are insufficient to evaluate the influence of both factorson human male fertility.  相似文献   

14.
Acrosomal status and viability were evaluated simultaneouslyon human spermatozoa using flow cytometry. Samples were dividedinto three aliquots and randomly assigned to one of three treatments:(i) cryopreservation; (ii) 10 µM calcium ionophore [A23187in dimethylsulphoxide (DMSO)] or (iii) DMSO alone (control).Acrosomal status was evaluated using monoclonal antibodies recognizingMH61 and CD46, respectively. Fluorescein-conjugated goat anti-mouseimmunoglobulin (IgG) was used as a second antibody. Sperm viabilitywas assessed using Hoechst 33258 (H258) exclusion. The followingfactors were analysed: (i) the specificity of the monoclonalantibodies for the human acrosome; (ii) the relative effectivenessof flow cytometry and direct fluorescent microscopy scoringand (iii) the acrosomal status and viability of the control,ionophore-treated, and cryopreserved spermatozoa. Across alltreatments, the MH61 and CD46 monoclonal antibodies resultedin acrosomal status values (acrosome-reacted/viable spermatozoa)which were not significantly different (P > 0.05): control,1.0 ± 0.3% and 1.5 ± 0.6% (mean ± SEM);A23187, 42.8 ± 3.5% and 38.1 ± 3.5%; cryopreserved,8.2 ± 2.0% and 9.9 ± 1.3%; respectively. However,acrosomal status among treatments differed significantly (P< 0.01). Flow cytometric and direct fluorescent microscopyassessments were significantly correlated (r2 = 0.96, P <0.01). These results indicate that flow cytometry, using anacrosome-specific monoclonal antibody and a supravital dye,provides an objective and efficient method to evaluate humansperm acrosomal and viability status simultaneously.  相似文献   

15.
The present study was designed to investigate the effect ofhuman cervical mucus on capacitation and the acrosome reactionof human spermatozoa and compare its effect to that of a cervicalmucus substitute, sodium hyaluronate (Healonid). Spermatozoafrom donors of proven fertility were isolated from semen usingcervical mucus, Healonid or a direct swim-up (acting as thecontrol). Sperm capacitation and the acrosome reaction weremonitored by the chlortetracycline assay. In the mucus-treatedgroup, there was a significantly higher percentage of capacitatedspermatozoa, but a low incidence of spontaneous and A23187-inducedacrosome reactions compared to the control. The use of Healonidduring sperm isolation mimicked the effect of mucus relativelysuccessfully. Since mucus and Healonid show very little chemicalsimilarity, this finding would imply that cervical mucus exertsa physical effect during its interaction with spermatozoa, althougha chemical effect cannot be completely dismissed. In conclusion,this study confirms early reports describing the ability ofcervical mucus to capacitate spermatozoa but at the same timeconserve sperm function. The finding that Healonid exerts analmost identical effect on spermatozoa would lend support toits use as a cervical mucus substitute during in-vitro fertilityassessments and research studies.  相似文献   

16.
The expression of genomic progesterone receptor in human ejaculatedspermatozoa was investigated. Spermatozoa from 10 fertile donorswho exhibited normal semen parameters were analysed. Indirectimmunofluorescence and an enzyme immunoassay using monoclonalantibodies against genomic progesterone receptor were used.Different types of spermatozoa were studied: fresh, post-swim-up(migrated), capacitated and post-artificial induction of theacrosome reaction by calcium ionophore A23187. Progestin receptor-richT47D human breast cancer cells were used as a positive control,and progestin receptor-poor MDA-MB-231 human breast carcinomacells were used as a negative control. Genomic progesteronereceptor was not detected in fresh, migrated, capacitated andpost-acrosome reaction induction human spermatozoa and MDA-MB-231cells by either indirect immunofluorescence or enzyme immunoassay.However, in T47D cells a mean concentration of 1043.2 ±125.2 fmol genomic progesterone receptor/mg protein was observedby enzyme immunoassay, and indirect immunofluorescence resultswere positive using both flow cytometry and fluorescence microscopy.These findings suggest that the effect of progesterone on humanspermatozoa is not mediated by genomic progesterone receptor.  相似文献   

17.
A Ca2+-dependent sialic acid-binding protein (SABP) of humanendometrium, which specifically bound to human sperm head plasmamembrane in vitro, was found to increase the percentage motilityand acrosome-reacted pattern of uncapacitated spermatozoa. Theprotein was synthesized in the endometrium and secreted intothe uterine fluid. This intra-uterine factor, which is apparentlyadvantageous in vitro in inducing human sperm capacitation,may play a significant role in promoting the postrelease maturationof ejaculated spermatozoa by enhancing 45Ca uptake into spermatozoaby a pathway which is insensitive to calcium-channel blockers.However, the 45Ca uptake could be enhanced on exposure to thedivalent cation ionophore A23187 and inhibited in the presenceof the calmodulin inhibitor trifluoperazine. The SABP also inducesan increase in intracellular Ca2+ in spermatozoa, as seen byFURA-2 AM studies. Furthermore, overlay studies show human SABPto be a Ca2+-binding protein. The data presented here suggestthat SABP induces invitro sperm capacitation and the subsequentacrosome reaction by increasing intracellular Ca2+ concentration.  相似文献   

18.
Motile human sperm populations were prepared from liquefiedsemen (10 donors x 3 replicates) using Percoll density gradientsat 30–60 min post-ejaculation. Sperm suspensions wereincubated in a complex ’synthetic tubal fluid‘ culturemedium (STF) at 37°C under 5% CO2 in air for up to 36 h.Parallel aliquots were incubated with 50 µM A23187 toinduce maximum acrosome loss (ARmax). Acrosome reactions wereassessed using both the triple-stain (TS) technique and fluorescentpeanut agglutinin (PNA) lectin-labelling. During incubation,the proportion of TS acrosome reacted spermatozoa increasedfrom 9.1 to 54.3% with ARmax being 68.3%. Spermatozoa showingintact acrosomes by PNA labelling decreased from 68.4 to 26.1%over 36 h of incubation (ARmax = 13.8%). Simultaneously, spermatozoashowing complete acrosomal loss (no PNA labelling) increasedfrom 8.1 to 27.0% (ARmax= 46.3%). Therefore, while only 23.5%of cells were actually undergoing acrosomal changes at the startof incubation, this had increased to 46.9% after 36 h (ARmax=40.7%). These experiments clearly show that even in selectedpopulations, not all human spermatozoa are capable of undergoingan acrosome reaction. However, the incidence of acrosomal changesafter 36 h of incubation did approach the ARmax. These levelsof spontaneous occurrence of the human sperm acrosome reactionwere higher than those reported in many other in-vitro incubationstudies: an improvement that may be attributable to the morephysiological nature of the STF culture medium  相似文献   

19.
In numerous animal species the acrosome reaction of spermatozoahas been linked to elevations in intracellular pH (pHi). However,whether or not this is merely a passive consequence of calciumion influx is not known. Studies into the fluctuations in pHiin sperm cells have been hampered by the lack of a pH-sensitiveprobe that could be used in conjunction with flow cytometry.In this study, flow cytometric analysis of pHi in human spermatozoawas accomplished by using one of the new benzo[c]xanthene dyes(SNAFL-1). SNAFL-1 was then observed in situ with conventionalfluorescent microscopy and was found to be located in the post-acrosomalcytoplasm of the head. It was then used to measure the differencesin pHi between acrosome-intact populations of spermatozoa, andpopulations that had been induced to acrosome-react with humanfollicular fluid or the calcium ionophore A23187 to mimic thecalcium influx. It was concluded that the human sperm acrosomereaction is also accompanied by a rise in pHi and the naturalagonist-induced rise could not be accounted for by calcium ioninflux alone. acrosome reaction/flow cytometry/human spermatozoa/intracellular pH/SNAFL-1  相似文献   

20.
Using human spermatozoa stimulated with either progesteroneor the Ca2+ ionophore A23187 to undergo acrosomal exocytosis,we have investigated potential pathways for generation of diacylglycerol(DAG) and have examined the possibility that DAG plays an importantrole in the exocytotic response. Both treatments resulted inrapid and considerable generation of DAG, followed by a limitedrise in phosphatidic acid (PA). Further experiments indicatedthat phospholipase C (PLC) activity is important in this generationof DAG, but phospholipase D activity probably is not. In addition,polyphosphoinositide-specific phosphoinositidase C activationand hydrolysis of phosphatidylinositol 4, 5-bisphosphate appearsto be a necessary prerequisite for activation of the PLC pathway.Finally the DAG formed appears to be important in acrosomalexocytosis: (i) blocking DAG metabolism with a DAG kinase inhibitorresulted in both increased endogenous levels of DAG and a significantlyincreased exocytotic response in stimulated cells and (ii) exogenousDAG induced exocytosis in capacitated spermatozoa whereas PAdid not. Taken together, these results suggest that DAG playsa key role in events leading to membrance fusion during humansperm acrosomal exocytosis stimulated by natural agonists. acrosome reaction/diacylglycerol/human spermatozoa/phospholipase C/phospholipase D  相似文献   

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