心肝核素显影比值对门静脉高压症的诊断价值

作者采用经直肠心肝核素显影法判断门静脉高压症。９１例经直肠注入￣９９ｍＴｃ－ＭＩＢＩ后测定心肝核素显影比值（Ｈ／Ｌ），结果显示正常对照组（１５例）Ｈ／Ｌ。为０．２６７±０．１，病毒性肝炎组（８例）Ｈ／Ｌ轻度上升（０．４５５±０．１３），而肝硬变组（６８例）则显著升高。其中Ｃｈｉｌｄ－Ａ组患者的Ｈ／Ｌ为０．５７±０．１２，ｃｈｉｌｄ－Ｂ组为１．０±０．１９，Ｃｈｉｌｄ－Ｃ组为１．１９±０．２５。Ｈ／Ｌ。与Ｃｈｉｌｄ－ｐｕｇｈ分级呈趋势相关（Ｐ＜０．０１）。２３例在手术时测定的门静脉压力与Ｈ／Ｌ，呈显著相关（ｒ＝０．８７，Ｐ＜０．０１）。从公式Ｙ＝０．７８５±３．２４Ｈ／Ｌ可以推算出门静脉压力。以Ｈ／Ｌ，≥０．６２为阳性标准诊断肝硬变门静脉高压的敏感度为９６％，特异度为８９％，准确率为９４％。经直肠￣９９ｍＴｃ－ＭＩＢＩ测定是无创伤性诊断门静脉高压的可靠安全的新方法。     

孕酮诱发人精子顶体反应及其对若干离子运动的调节

采用ｌｅｃｔｉｎ染色法、原子吸收光谱法及电化学法就孕酮诱发人精子顶体反应，及其对顶体反应时Ｎａ＋、Ｋ＋、Ｃａ２＋、Ｍｇ２＋和Ｃｌ－离子运动情况进行了研究。结果表明：（１）孕酮可使人精子顶体反应率明显增加（Ｐ＜０．０５）。（２）经孕酮作用后，Ｎａ＋、Ｃａ２＋和Ｍｇ２＋向精子内流动，而Ｋ＋外流；Ｃｌ－外流后又内流。由此可见，孕酮对人精子顶体反应时离子运动有调节作用。     

细胞松弛素D对人类精子顶体反应的影响

为了观察细胞松弛素Ｄ（ＣＤ）对人类精子顶体反应（ＡＲ）的诱导作用，分别使用不同浓度的ＣＤ处理获能后的人精子，以钙离子载体Ａ２３１８７作为阳性对照，采用双重染色法检测精子的ＡＲ发生率。结果当ＣＤ浓度为３０μｍｏｌ／Ｌ及５００μｍｏｌ／Ｌ时，人精子的ＡＲ发生率分别为２８．０±９．０％及２８．６±２．８％，与空白对照组的１７．９±５．５％相比较有明显增加，差异有显著性（Ｐ＜０．０５）。表明适当浓度的ＣＤ是一种良好的人类精子顶体反应诱导剂     

骨代谢生化指标随年龄的变化及其临床意义

本文收集了北京地区１９２８名不同年龄（０～８７岁）健康人及５３４５例２０余种疾病患者空腹尿及血，并对其骨代谢生化指标进行测定。结果表明：血清２５羟基维生素Ｄ（２５ＯＨＤ），碱性磷酸酶（ＡＬＰ），骨钙素（ＢＧＰ），甲状旁腺激素（ＰＴＨ），尿Ⅰ型胶原交联Ｎ末端肽与肌酐比值（ＮＴＸ／Ｃｒ）及羟脯氨酸与肌酐比值（ＨＯＰ／Ｃｒ）与年龄显著相关。血清２５ＯＨＤ，ＢＧＰ，尿ＮＴＸ／Ｃｒ及ＨＯＰ／Ｃｒ可用于预测骨量。１，２５（ＯＮ）２Ｄ３，２５ＯＨＤ，ＮＴＸ／Ｃｒ和ＮＯＰ／Ｃｒ可用于区分绝经前与绝经后骨质疏松妇女。与年龄有关的骨丢失可能与１，２５（ＯＨ）２Ｄ３的降低、ＰＴＨ的升高及肾功能减退有关；绝经后骨丢失与雌激素缺乏有关。     

胰岛素对人卵泡内泡膜细胞分泌雄激素的影响

培养取自月经周期正常妇女卵泡期卵泡的内泡膜细胞，观察人绒毛膜促性腺激素（ｈＣＧ）和胰岛素（ＩＮＳ）对内泡膜细胞分泌雄烯二酮（Ａ）、１７α羟孕酮（ＯＨ－Ρ）和孕酮（Ｐ）的影响。结果表明，ｈＣＧ和ＩＮＳ均刺激内泡膜细胞增加Ａ、ＯＨ－Ｐ和Ｐ的分泌。两者刺激内泡膜细胞分泌激素增加的浓度分别是０．５ＩＵ／ｍｌ和１０ｎｇ／ｍｌ。与基础状态相比，ＩＮＳ（５ｎｇ／ｍｌ）刺激Ａ、ＯＨ－Ｐ、Ｐ的分泌分别增加２．９、４．７和２．４倍，ｈＣＧ（０．１ＩＵ／ｍｌ）分别增加７．４、３．４和２．８倍；ＩＮＳ＋ｈＣＧ共同刺激分别增加９．５、９．３和４．３倍。ＩＮＳ在人卵巢甾体激素的合成中起重要的调节作用     

补体在重度烧伤病人PMN吞杀绿脓杆菌力中的作用

采集了７０例烧伤病人１２９份外周血中性粒细胞（ＰＭＮ），以Ｏ~２￣－、特殊颗粒（ＳＧ）和胞内杀菌力（ＩＣＢＡ）为指标动态观测了深度烧伤后病人的ＰＭＮ水平变化；分析了病人血浆对正常人ＰＭＮ胞内指标的有害作用，及抗人Ｃ~３、Ｃ~５血清（ＡＨＣ~３Ｃ~５Ｓ）对上述有害作用的特异阻断效能。结果表明：①重、中度烧伤病人的各指标值均显著低于正常水平（Ｐ＜０．０５）；当ＢＳＤ（深度烧伤面积）≥４５％和病程在１～６天时，ＩＣＢＡ最低。②ＩＣＢＡ与ＳＧ和Ｏ~２￣－的动态相关显著（Ｐ＜０．０５）。③病人血浆能显著削减正常人ＰＭＮ胞内ＩＣＢＡ、ＳＧ和Ｏ~２￣－的储存，而ＡＨＣ~３Ｃ~５Ｓ能减轻这些储存的丢失，效能由保护率表示：ＩＣＢＡ（６７．３３％）＞ＳＧ（５１．６０％）＞Ｏ~２￣－（４６．６８％）。结果提示：ＰＭＮ杀菌力的高低与ＢＳＤ和病程早晚呈负相关，Ｃ~３、Ｃ~５碎片是ＰＭＮ胞内ＩＣＢＡ下降的重要直接因素。     

1α，25双羟维生素D3对成骨样细胞增殖与分化的影响

采用同位素掺入，细胞周期、细胞化学和扫描电镜等方法观察了１α，２５双羟维生素Ｄ３［１，２５（ＯＨ）２Ｄ３］对人及大鼠成骨样细胞ＯＳ－７３２和ＲＯＳ１７／２．８增殖及分化的影响。结果表明：１，２５（ＯＨ）２Ｄ３对ＯＳ－７３２细胞增殖的抑制作用呈明显的时效和量效关系。在给１０－７ｍｏｌ／Ｌ的１，２５（ＯＨ）２Ｄ３后第４和第６天，对ＯＳ－７３２细胞生长的抑制率分别为４０％和６０％；对ＤＮＡ，ＲＮＡ和蛋白质合成的抑制作用分别为５９％，４１％和２２％。流式细胞计测定结果表明：１，２５（ＯＨ）２Ｄ３使ＤＮＡ合成受阻；扫描电镜显示：１，２５（ＯＨ）２Ｄ３有抑制ＲＯＳ１７／２．８细胞表面微绒毛的作用。此外，细胞化学染色表明：该激素有增加成骨样细胞碱性磷酸酶活性和促进骨形态形成蛋白合成的作用，即刺激骨形成的作用。     

应用宫高/身高比值预测麻醉平面对剖宫产患者呼吸的影响

目的：测定健康足月妊娠妇女宫高／身高（ＨＯＵ／ＢＨ）正常值范围，并在此范围内探讨ＨＯＵ／ＢＨ于不同麻醉平面下对患者呼吸功能的影响。方法：患者在不同阻滞平面下，按ＨＯＵ／ＢＨ值分Ａ１（大于０．２１）、Ａ２（小于０．２１）和Ｂ１（大于０．２１）、Ｂ２（小于０．２１）四个亚组，其中Ａ１、Ａ２为高平面组，Ｂ１、Ｂ２为低平面组。各组分别于麻醉前、胎儿娩出前、娩出后３０分钟记录ＶＴ、ＲＲ、ＳｐＯ２。结果：健康足月妊娠妇女ＨＯＵ／ＢＨ正常值范围０．１６～０．２５。ＨＯＵ／ＢＨ大于０．２１，麻醉平面高于Ｔ６时ＶＴ将减少，ＲＲ增加，ＳｐＯ２降低，患者常诉有呼吸困难。结论：ＨＯＵ／ＢＨ大于０．２１的剖宫产患者，应适当掌握麻醉平面，以免影响其通气功能。     

大剂量升压药抢救大出血一例报告

患者．男，６８岁，体重５８ｋｇ，因脑膜瘤入院。术前检查：血压１６／１０ｋＰａ，血红蛋白１５２ｇ／Ｌ；ＥＣＧ示窦性心律，心率８０次／分，Ｓ－Ｔ在Ⅱ、Ⅲ、ａｖＦ、Ｖ３～６导联中均下移；血清钾３．８ｍｍｏｌ／Ｌ、钠１２４．４ｍｍｏｌ／Ｌ、氯９５．６ｍｍｏｌ／Ｌ；头颅ＣＴ示：大脑镰左侧脑膜瘤。麻醉经过术前肌注阿托品０．４ｍｇ，入室行ＥＣＧ及生命体征监测，血压２２／１２ｋＰａ、心率１００次／分。开放两条液路，安定１０ｍｇ、冬眠Ⅰ号２ｍｌ、２５％－ＯＨ１４．５ｍｌ、２．５％硫喷妥钠９ｍｌ分别分次静脉滴入，咽…     

迅速纠正代谢性酸中毒对慢性肾功能衰竭继发性甲旁亢患者的作用

为探讨纠正代谢性酸中毒对慢性肾功能衰竭（ＣＲＦ）继发性甲旁亢（ＳＨＰ）的作用。方法对１５例透析前ＣＲＦ患者迅速纠正代谢性酸中毒前后甲状旁腺素（ＰＴＨ）和１，２５（ＯＨ）２Ｄ３水平进行了比较。结果治疗后血清ｍＰＴＨ、ｉＰＴＨ和ＰＯ３－４等水平明显下降（２．２９±１．２６ｖｓ１．７４±０．８３μｇ／Ｌ，Ｐ＜０．００５；４６１．８±２７０．９ｖｓ３３２．１±１９９．７μｇ／Ｌ，Ｐ＜０．０１；５．３３±２０．８ｖｓ４８．７±２０．４ｍｇ／ｌ，Ｐ＜０．００１）；１，２５（ＯＨ）２Ｄ３水平有所升高，但尚不显著；血浆游离钙（ｉＣａ）、血清总钙（ｔＣａ）等水平均无明显变化。结论纠正代谢性酸中毒可降低慢性肾衰ＳＨＰ患者血清ＰＴＨ水平，有利于ＳＨＰ的改善；代谢性酸中毒对慢性肾衰ＳＨＰ的发生或发展可能起重要作用     

Role of ions and ion channels in capacitation and acrosome reaction of spermatozoa

Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of binding and fusionwith the oocyte. During capacitation various biochemical and biophysical changes occur in the spermatozoa and thespermatozoal membranes. Ions and ion channels also play important roles in governing the process of capacitation bychanging the fluxes of different ions which in turn controls various characteristics of capacitated spermatozoa. Alongwith the mobilization of ions the generation of free radicals and efflux of cholesterol also plays an impo~.nt role in thecapacitation state of the spermatozoa. The generation of free radical and efflux of cholesterol change the mechano-dynamic properties of the membrane by oxidation of the polyunsaturated lipids and by generating the cholesterol freepatches. The process of capacitation renders the spermatozoa responsive to the inducers of the acrosome reaction. Theglycoprotein zona pellucida 3 (ZP3) of the egg coat zona pellucida is the potent physiological stimulator of the acro-some reaction; progesterone, a major component of the follicular fluid, is also an inducer of the acrosome reaction.The inducers of the acrosome reaction cause the activation of the various ion-channels leading to high influxes of calci-um, sodium and bicarbonate. The efflux of cholesterol during the process of capacitation alters the permeability of themembrane to the ions and generate areas which are prone to fusion and ve.siculation process during the acrosome reactioa. this review focuses mainly on effects of the ion and ion-channels, free radicals, and membrane fluidity changesduring the process of capacitation and acrosome reaction.     

Effect of genistein on acrosome reaction and zona pellucida binding independent of protein tyrosine kinase inhibition in bull

Aim： To investigate if the phytoestrogen, genistein, affects essential functions of cryopreserved bovine spermatozoa. Methods： The effect of genistein upon motility was assessed by computer-assisted motion analysis. Hemizona assay was performed to detect the ability of spermatozoa binding to the zona pellucida. The inducibility of the acrosome reaction using progesterone and ZP3-6 peptide was analysed by fluorescein-conjugated Pisum sativum agglutinin （FITC-PSA）/Hoechst 33258 double staining. Capacitation after incubation with genistein was assessed by the chlortetracycline （CTC） assay. Immunoblots showed the pattern of protein tyrosine phosphorylation of cryopreserved bovine spermatozoa. Results： Immunodetection of tyrosine-phosphorylated proteins showed that genistein did not affect tyrosine phosphorylation in cryopreserved bovine spermatozoa. However, genistein significantly reduced the progesterone- and ZP3-6 peptide-mediated induction of the acrosome reaction and led to a dose-dependent inhibition of sperm-zona pellucida binding; while sperm motility and capacitation were not affected by this phytoestrogen, as indicated by computer-assisted sperm motion analysis and the CTC assay, respectively. Conclusion： Our results suggest that in cryopreserved bovine spermatozoa, genistein affects a protein tyrosine phosphorylation-independent signal transduction pathway that is involved in sperm capacitation, the acrosome reaction and sperm-zona pellucida binding.     

Relationship between the proportion of capacitated spermatozoa present in frozen-thawed bull semen and fertility with artificial insemination

The objective of the present study was to confirm the presence of prematurely capacitated spermatozoa in frozen-thawed bull semen and to investigate the relationship of premature capacitation to the fertility of the respective semen. Twenty batches of frozen semen from young AI bulls of the Swedish Red and White breed with known fertility (expressed as 56-day non-return rates; 56 d-NRR) were tested using a Chlortetracycline (CTC) assay to assess capacitation status in frozen-thawed spermatozoa. The status of capacitation, as evidenced in this experiment, was further tested based on the hypothesis that capacitated spermatozoa present in frozen-thawed semen should undergo the acrosome reaction (AR) on co-incubation with homologous zona pellucida (ZP) glycoproteins. The percentage (mean +/- SEM) of uncapacitated, capacitated and acrosome-reacted spermatozoa in the frozen-thawed semen (n = 20) were 49.3 +/- 11.9, 36.3 +/- 8.3 and 14.2 +/- 11.9, respectively. On co-incubation with ZP, there was a significant increase (p = 0.001) in the proportion of spermatozoa undergoing the AR compared to the control with a concurrent decrease in the proportion of capacitated spermatozoa, suggesting that a proportion of capacitated spermatozoa were undergoing the AR. The proportion of viable, uncapacitated spermatozoa present in the frozen-thawed semen was correlated to the 56 d-NRR (n = 20, r = 0.5, p = 0.03). In conclusion, a proportion of spermatozoa in frozen-thawed semen was capacitated and the proportion of viable, uncapacitated spermatozoa present in semen was positively correlated to fertility.     

Differential activities of malate and isocitrate NAD(P)-dependent dehydrogenases are involved in the induction of capacitation and acrosome reaction in cryopreserved bovine spermatozoa

Sperm catabolic processes produce energy for capacitation and acrosome reaction induction required for oocyte fertilization. The aim was to determine metabolic enzymes' activities and their participation in the supply of energy and generation of the redox state to acquire fertilizing capacity. Capacitation was induced with heparin and quercetin, and the acrosome reaction with progesterone. Enzymatic activities were determined spectrophotometrically. The chlortetracycline and differential-interferential contrast microscopy/tryptan blue techniques were used to evaluate capacitation and acrosome reaction, acrosomal integrity and sperm viability respectively. A 2 : 1 and 3 : 1 ratio were obtained for isocitrate dehydrogenase (IDH)-NADP/NAD and malate dehydrogenase (MDH)-NADP/NAD activities respectively. MDH-NADP activity remained constant with different treatments, unlike MDH-NAD activity, which diminished with both capacitation inducers and in acrosome-reacted spermatozoa previously treated with heparin (P < 0.05). IDH-NADP decreased its activity 50% in spermatozoa capacitated with heparin and acrosome reacted with progesterone (P < 0.05). Capacitation and acrosome reaction processes induced with heparin and progesterone, respectively, involve a differential oxidative metabolism, with the participation of MDH-NAD(P) and IDH-NAD(P) enzymes, whose activities would be linked to the malate-aspartate, lactate-pyruvate and isocitrate cytosolic-mitochondrial shuttles. These enzymes play a major role in supplying reduction equivalents and/or energy required for capacitation and acrosome reaction in cryopreserved bovine spermatozoa.     

Participation of membrane adenylyl cyclase in heparin‐induced capacitation in cryopreserved bovine spermatozoa

The aim of this work was to study the participation of membrane adenylyl cyclase in heparin‐induced capacitation in cryopreserved bovine spermatozoa. Sperm suspensions were incubated in Tyrode's albumin lactate pyruvate medium in the presence of heparin (10 IU ml^?1) or forskolin (1–75 μm ), a well‐known membrane adenylyl cyclase activator. The participation of membrane adenylyl cyclase was confirmed using a specific inhibitor, 2′,5′‐dideoxyadenosine (6–25 μm ). Spermatozoa capacitated with forskolin (25 μm ) were incubated with bovine follicular fluid to evaluate their ability to undergo acrosome reaction. Capacitation percentages were determined by the fluorescence technique with chlortetracycline, and true acrosome reaction was determined by trypan blue and differential interferential contrast. The forskolin concentrations employed had no effect on progressive motility or sperm viability. Capacitation values induced by 25‐μm forskolin treatment (27.80 ± 2.59%) were significantly higher respect to the control (4.80 ± 1.30%). The inhibitor 2′,5′‐dideoxyadenosine prevented forskolin‐induced capacitation and significantly diminished capacitation induced by heparin. Follicular fluid induced physiological acrosome reaction in spermatozoa previously capacitated with 25‐μm forskolin (P < 0.05). Forskolin acts as a capacitation inducer and involves the participation of membrane adenylyl cyclase as part of the intracellular mechanisms that lead to capacitation in cryopreserved bovine spermatozoa.     

Sperm-immobilizing antibodies block capacitation in human spermatozoa

Sperm-immobilizing antibodies block human fertilization by interfering with the acrosome reaction (AR). To clarify the mechanism of blockage of AR by sperm-immobilizing antibodies, the authors examined their effects on the increase of intracellular free Ca2+ concentration induced by follicular fluids (Ca2+ influx) in spermatozoa and on their capacitation. Sperm-immobilizing antibodies did not suppress Ca2+ influx induced by follicular fluid, but they inhibited capacitation of human spermatozoa. Namely delta%AR (%AR after addition of an AR inducer--%AR before treatment) induced by progesterone was significantly (p < .0001) lower when spermatozoa were incubated in human tubal fluid medium cotaining antibody-positive serum (1.2%), compared to that when incubated in control medium (19.2%). Furthermore, the proportion of both spermatozoa that became capacitated and ones that had become capacitated decreased significantly (p < .0001) after 2, 4, and 6 h of incubation in medium containing antisperm antibody-positive serum, compared to those of spermatozoa incubated in control medium. In conclusion, sperm-immobilizing antibodies may be closely related to their blockage of capacitation.     

Extracellular signal-regulated kinase activation involved in human sperm-zona pellucida binding

In a previous study involving the inhibition the mitogen-activated protein kinase (MAPK), extracellular signal regulated kinase (ERK), we found that the very specific MAPK kinase (MEK) inhibitor, PD098059, inhibited the zona pellucida (ZP) induced acrosome reaction. As an intact acrosome on the spermatozoa is a prerequisite in ensuring tight binding to the ZP, we investigated the zona binding potential of spermatozoa after PD098059 treatment of sperm, followed by exposure to solubilised human ZP and calcium ionophore (A23187). PD098059 treated spermatozoa, exposed to solubilised ZP, bound significantly more to the ZP, as compared to control spermatozoa also exposed to solubilised ZP (26.5 +/- 3.7 vs. 13.8 +/- 2.8, P < 0.05). No significant differences in binding to the ZP were observed between PD098059 treated and untreated sperm populations after A23187 exposure. These results can be interpreted to support the idea that the ZP-induced AR is the physiologically relevant exocytotic event, as it is the ZP-induced AR, and not the spontaneous (culture medium) or A23187 induced AR, that appears to be mediated through an ERK-mediated signal transduction process.     

己酮可可碱、孕酮和A23187对人精子甘露糖受体表达的影响

人精子经ＢＷＷ获能５～６小时后，分别用己酮可可碱（ＰＦ）、孕酮（Ｐ）和Ａ２３１８７三种已知的获能及（或）顶体反应促进剂处理１小时，对实验和对照组精子用异硫氰酸荧光素标记的甘露糖化牛血清白蛋白（Ｍ ＦＩＴＣ ＢＳＡ）作探针标记精子甘露糖受体（ＭＲ）。结果表明，获能促进剂ＰＦ并不促进ＭＲ表达而Ｐ和Ａ２３１８７则有显著促进ＭＲ表达的作用。Ｐ对ＭＲＩＩ型的促表达作用略强于对ＩＩ型，而Ａ２３１８７则对ＩＩ型的促进显著强于Ｉ型。认为ＭＲ的表达是一种依赖于钙离子的细胞生物学过程，并与顶体反应有密切关系。推测ＭＲ可能具有介导精子与卵膜融合的作用。     

Zona pellucida mediated acrosome reaction and sperm morphology

Summary. Sperm samples from 29 men randomly selected from the andrology laboratory, were used to evaluate acrosome reaction response to solubilized human zona pellucida. Capacitated sperm samples were exposed to a solution containing 2 zona pellucidae (ZP) per μl for 60 min, after which acrosomal status were recorded using a PSA-FITC technique. Controls included samples supplied by fertile sperm donors. After completion of acrosome reaction studies, patient samples were divided according to the percentage of morphologically normal spermatozoa. Three basic groups were identified, namely, fertile donors, teratozoo-spermic (normal sperm morphology 5–14%; n = 25) and severely teratozoospermic (normal sperm morphology <4%; n = 4) groups. The mean percent normal sperm were 15.8 ± 0.9, 10.4 ± 0.7 and 2.7 ± 0.7, respectively, for normozoospermic donors, teratozoospermic and severely teratozoospermic men. The mean percentage (± SE) ZP mediated acrosome reacted sperm among teratozoospermic and severely teratozoospermic cases was 25.8% ± 0.9 and 19.0% ± 0.9 (P = 0.001), compared to 36.8% ± 0.9 for the donor controls. Results were analysed and expressed as correlations between sperm morphology and acrosomal response to human solubilized zona pellucida, spontaneous and calcium ionophore induced acrosome reaction. Predictive values for acrosome responsiveness were depicted with ROC curve analyses. Sperm morphology evaluated by strict criteria correlated positively and highly significantly with the responsiveness of the acrosome reaction (r = 0.91, P = 0.0001). At a morphology cut-off value of 4%, the ROC curve analysis showed sperm morphology to be highly predictive of zona pellucida induced acrosome responsiveness with a sensitivity of 100% and negative predictive value of 100%. Spontaneous and calcium ionophore induced acrosome reactions revealed no correlation with sperm morphology. It was concluded that (i) morphological features of human spermatozoa are indicative of specific functional characteristics; (ii) zona pellucida induction of the acrosome reaction is superior, as a predictor of sperm morphology, compared to calcium ionophore induced and spontaneous acrosome reactions.     

Acrosome reaction: relevance of zona pellucida glycoproteins

During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four (ZP1, ZP2, ZP3 and ZP4). ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans (in addition to ZP3), ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the G_i-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels (VOCCs), whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans (in addition to ZP3), ZP1 and ZP4 also participate in these stages of fertilisation.