Very low-dose (femtomolar) 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) disrupts steroidogenic enzyme mRNAs and steroid secretion by human luteinizing granulosa cells.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most toxic congener of the polyhalogenated aromatic hydrocarbons (PAH), which causes anatomical abnormalities and developmental defects, impairs ovulation and reduces fertility. TCDD's endocrine-disrupting effects are, in part, caused by a direct action at the ovary. Herein we investigated the in-vitro effects of environmentally relevant doses of TCDD on estradiol-17ß (E2) production by human luteinizing granulosa cells (hLGC) obtained from women stimulated for in-vitro fertilization (IVF). TCDD at all concentrations tested (3.1fM, 3.1pM and 3.1nM) significantly decreased E2 secretion when assayed for by radioimmunoassay (RIA). Herein we confirm that TCDD alters E2 secretion by hLGC in a time-, not dose-dependent fashion and are the first to show decreases in E2 secretion with fM concentrations of TCDD. Using real-time quantitative PCR (RT-qPCR), the decreased E2 secretion correlates with a decrease in the mRNA expression levels two enzymes in the estrogen biosynthesis pathway: CYP11A1 and CYP19A1.

Dioxin perturbs, in a dose- and time-dependent fashion, steroid secretion, and induces apoptosis of human luteinized granulosa cells.

Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD) is the most toxic congener of a large class of environmental pollutants. Several studies have shown that TCDD exposure reduced fecundity and ovulatory rate in rats and increased the incidence of endometriosis in monkeys. Recent work suggests that TCDD's endocrine-disrupting effects are, at least in part, caused by a direct action at the ovary. Although the factors involved in TCDD-induced toxicity are still under investigation, several studies have shown that TCDD induces programmed cell death, or apoptosis, in various tissues and may act in a similar fashion in the ovary. In the present study, we set out to evaluate the in vitro effects of TCDD on steroid secretion, specifically estradiol-17beta (E2) and progesterone, by human luteinized granulosa cells (LGC), and to further determine whether TCDD is capable of inducing apoptosis in this cell type. Human LGC were obtained from women participating in an in vitro fertilization program. Medium, with or without three different concentrations of TCDD and substrates [androstenedione (A4) or pregnenolone], was added to each culture. The media were collected at 4, 8, 12, 24, 36, and 48 h and were assayed by RIA. At 24 and 48 h, the LGC were fixed for assessment of DNA fragmentation via an in situ immunofluorescence technique. Transmission electron microscopy was also performed on LGC after 24 and 48 h with TCDD. TCDD, at all concentrations tested (3.1 pM, 3.1 nM, and 3.1 microM), significantly reduced E2 accumulation in the media at 8, 12, and 24 h, compared with controls. At 36 and 48 h, TCDD treatment (at 3.1 microM) caused a significant increase in E2, compared with controls. The effect of TCDD on E2 was abolished with the addition of A4. TCDD treatment did not alter progesterone accumulation. Apoptosis increased at 24 h with 3.1 microM TCDD, with no apparent effect at 3.1 nM. By 48 h, however, TCDD increased apoptosis in a dose-dependent manner. Transmission electron microscopy showed ultrastructural differences in LGC with 3.1 microM TCDD at 24 and 48 h. Collectively, the results of the present study suggest that TCDD perturbs E2 secretion by depletion of A4 precursor and increases apoptotic cell death of human LGC in a dose- and time-dependent fashion.

The relationship of human granulosa-lutein cell proliferative index to follicular diameter and serum estradiol.

OBJECTIVE: To examine the relationships of follicular diameter and serum estradiol (E2) to the percentage of granulosa cells undergoing mitosis as reflected by the proliferative index of granulosa cells. METHODS: In this prospective study, we enrolled 44 consecutive women undergoing controlled ovarian hyperstimulation for in vitro fertilization. Deoxyribonucleic acid histograms were generated by flow cytometry from granulosa cells isolated at the time of transvaginal aspiration. Proliferative index was defined as the sum of G2/M and S phases. We assessed the correlation between proliferative index and age, maximum serum E2, number of oocytes retrieved, percent mature oocytes, and follicular diameter. RESULTS: Follicles less than 16 mm had a significantly higher proliferative index (19.9 +/- 3.3%) than follicles 20 mm or greater (14.8 +/- 3.9%, P = .016). However, there was no significant difference between proliferative index of the latter group and proliferative index of follicles 16-19 mm (17.8 +/- 4.7%). An inverse correlation between patient age and proliferative index of granulosa cells was noted (r = -.39, P = .018). There was no significant relationship between serum E2 and proliferative index (P = .97). CONCLUSION: Mitotic activity tends to decrease as follicular diameter increases after a threshold diameter is achieved. Proliferative index of granulosa cells provides insight into the underlying cell biology of a follicle.

Modulation of ovarian follicle maturation and effects on apoptotic cell death in Holtzman rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in utero and lactationally.

Recent reports have described the reproduction-modulating and endocrine-disrupting effects following exposure to toxic substances such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Herein, we set out (1) to determine whether TCDD exposure exerts detrimental effects on follicle maturation in the Holtzman rat ovary and (2) to determine whether the effects of TCDD are mediated in part via apoptotic cell death. In certain species, dioxin exposure is correlated with reduced fecundity, reduced ovulatory rate, an increased incidence of endometriosis, and various reproductive cancers. Although some of the effects of TCDD are mediated via the hypothalamic-pituitary axis, direct effects on the ovary have also been observed. In the present study, an oral dose of 1 microgram TCDD/kg maternal body weight was administered on Day 15 of gestation. Female pups were sacrificed on Postnatal Day 21/22, and the ovaries were excised, fixed for histologic analysis, and analyzed in a double-blind paradigm. The analysis included a count and measurement and classification of preantral and antral follicles throughout the entire ovary. The contralateral ovary from each animal was analyzed for DNA fragmentation indicative of apoptotic cell death. The results indicate that TCDD treatment significantly reduced the number of antral follicles in the size classes 50,000 to 74,999 microns2 and > 100,000 microns2. We also observed a reduction in the number of preantral follicles less than 50,000 microns2. No difference was observed in the degree of apoptotic cell death in antral (50,000 to > 100,000 microns2) and preantral follicles (50,000 microns2 to > 75,000 microns2) between TCDD-treated and control-treated tissues. These data support the hypothesis that TCDD results in a diminution in the number of antral and preantral follicles of certain size classes in animals exposed during critical periods of development, but that apoptosis does not appear to be the underlying mechanism in these particular follicles. This does not preclude apoptosis occurring in pools of smaller precursor follicles.

Oocyte maturation in rabbits: effects of calmodulin inhibitors.

Oocyte maturation in mammals follows a highly conserved pattern of release from arrest through to the extrusion of the first polar body and formation of the second metaphase spindle. Oscillations in cytoplasmic calcium concentration precede the events of maturation in many species. These calcium ions interact with and activate calcium-binding proteins, including calmodulin, within the cell. Thus, it was of interest to us to examine whether calcium acted through calmodulin in the initial stages of maturation in rabbit oocytes or whether calmodulin was required for continuation through metaphase I no to metaphase II. Using the calmodulin inhibitor W-7 we found a significant (p < 0.05) decrease in the percentage of oocytes that underwent germinal vesicle breakdown. Calmidazolium did not prevent germinal vesicle breakdown; however, it caused a significant (p < 0.05) decrease in the proportion of oocytes with fully elaborated spindles and taxol-induced cytoplasmic asters. Both inhibitors caused a significant (p < 0.05) reduction in the proportion of oocytes that extruded their first polar bodies. The kinase inhibitor 6-DMAP caused a significant reduction in the proportion of oocytes with spindles and condensed chromatin, indicating the necessity for phosphorylation events in the resumption of meiosis. In rabbit oocytes calmodulin may play a role in the release from prophase arrest, and it is necessary for spindle preservation and continuation through metaphase I to metaphase II. The varying effects of the two inhibitor stems from their different binding sites on the calmodulin molecule thus causing a differential effect on its downstream effectors.

Comparison of mouse embryo development in open and microdrop co-culture systems.

Co-culture with numerous cell lines has been shown to improve in-vitro embryo development. It is usually performed in open culture without an oil overlay, or in relatively large volumes of medium (e.g. 0.5 ml) under oil. We compared the efficacy of open and microdrop co-culture systems using human endometrial and tubal cell lines and mouse zygotes. Although the mean pH values of the media from the tubal cell cultures (both open and oil-covered) decreased significantly over 5 days of culture, this did not appear to impair embryo development. Both co-culture and microdrop culture significantly improved blastocyst and hatching blastocyst formation rates. The combination of the two techniques (microdrop and co-culture) demonstrated the highest blastocyst formation and hatching blastocyst formation rates, as well as the highest mean cell numbers in hatching blastocysts. Co-culture in a microdrop is a superior system for mouse embryo culture.

Optimizing tubal epithelial cell growth promotes mouse embryo hatching in coculture.

PURPOSE: This study investigates the relationship between human tubal epithelial cell growth characteristics and mouse embryonic development to determine which cellular requirements should be preferentially provided in a coculture system. METHODS: Cell growth and viability were assessed for 5 days in alpha-minimal essential medium or human tubal fluid supplemented with 10% human serum or 10% synthetic serum. Two-cell mouse embryo development to blastocyst and hatching blastocyst stages was also assessed with or without coculture. RESULTS: Both epithelial cell growth and embryo development were dependent on serum supplementation with better cell viability and growth rates in human serum and better blastocyst development in synthetic serum. The highest proportion of hatching blastocysts was found in alpha-minimal essential medium and human serum with coculture. CONCLUSIONS: Culture conditions which improve tubal epithelial cell growth also improve the hatching rate of mouse embryos in coculture. This indicates that by meeting the metabolic and nutritional demands for epithelial cell growth, the beneficial effects of coculture on embryo development may be optimized.

Estrogen receptor and aromatic hydrocarbon receptor in the primate ovary.

We have previously shown by immunocytochemistry and autoradiography the presence of estrogen receptors (ER) in rhesus monkey ovary. Intense chromogen staining showed specific binding for ER in nuclei of germinal epithelium and granulosa cells of antral follicles; and radiolabeled ligand bound specifically to functional corpora lutea (CL). Although it is accepted that the germinal epithelium of the primate ovary contains ER, some controversy still persists regarding the intraovarian localization of this molecule. In addition, no data exist that localize the aromatic hydrocarbon (dioxin) receptor (AHR), which is known to modulate ER, to the primate ovary. In the present study, we show the presence of ER using Western blot analysis, and ER capable of binding DNA within intraovarian compartments in two species of the genusMacaca (rhesus macaque,Macaca mulatta and stumptail macaque,Macaca arctoides); extend these findings to human ovarian granulosa cells (GC) using Western blot, reverse transcription-polymerase chain reaction (RT-PCR), and gel mobility-shift analysis; and localize the AHR to intraovarian compartments of the macaque ovary by Western blots and gel-shift assays. These experiments strongly suggest that estrogens can exert effects on follicle development directly at the ovary, and provide the first direct evidence that AHR-mediated toxicity may be manifested at the ovary to induce possible antifertility effects.

Evaluation of co-culture and alternative culture systems for promoting in-vitro development of mouse embryos.

The goal of this study was to compare mouse embryo development in a defined synthetic medium (human tubal fluid) against the same medium supplemented with a defined synthetic serum (SS), co-culture on human tubal epithelium (TECC), and culture on human fibronectin (FN) with and without SS. After 48 h, TECC, SS and FN + SS cultures demonstrated accelerated development with > 70% achieving > or = 8-cell stage. After 72 h, these culture conditions also significantly increased the proportion of embryos reaching the blastocyst stage but only TECC significantly increased the number of hatching blastocysts. Nuclei of the trophectoderm of unhatched and hatched blastocysts were stained with propidium iodide before fixing and labelling both the trophectoderm and inner cell mass with bisbenzimide. Blastocysts from the TECC contained a significantly higher total cell number (TCN) and trophectoderm and inner cell mass cell numbers than all other groups. These findings indicate equivalent improvements in mouse embryo development to the blastocyst stage in response to TECC, SS and FN and an enhanced number of cells and rate of hatching found only with TECC.

Luteal phase estradiol and pregnancy outcome in gonadotropin releasing hormone agonist/human menopausal gonadotropin-treated gamete intrafallopian transfer cycles.

To correlate luteal estradiol (E2) levels with pregnancy outcome, 36 consecutive conceptions resulting from gamete intrafallopian transfer in gonadotropin releasing hormone agonist/human menopausal gonadotropin (GnRH-a/hMG) cycles were analyzed. GnRH-a was initiated during the preceding luteal phase. HMG was adjusted individually. Human chorionic gonadotropin (hCG), 5,000 IU, was administered when E2 was > 500 pg/mL and the leading follicle > 17 mm (day 0). The luteal phase was supported by (1) hCG, 1,500 IU in three doses from day 5 and (2) progesterone (P) from day 7. E2 and P levels were analyzed in three groups of patients: normally progressing pregnancy (NPP), abortion (AB) and preclinical abortion (PAB). No significant differences in mean E2 levels were seen between the groups from day 0 through day 5 after hCG. Midluteal E2 levels were significantly different between the groups (P < .05). Late luteal E2 values were significantly higher for NPP than for either AB or PAB (P < .05). There were no significant differences in luteal P values between the NPP, AB and PAB groups. Decreased luteal E2 appears to be associated with early pregnancy wastage; this may be due to inadequate endometrial support.

Elevated follicular fluid angiotensin II and pregnancy outcome.

OBJECTIVE: To assess whether a relationship exists between follicular fluid (FF) angiotensin II (AII) concentration and pregnancy outcome or earlier fecundity parameters and whether correlations exist among FF AII concentrations and P, E2, T, androstenedione (A), or various ratios of these. DESIGN: Retrospective study in which hormone concentrations in FF samples were measured. SETTING: In vitro fertilization clinic-Assisted Reproductive Technology Program, Rush Medical Center. PATIENTS: Twenty-six female patients underwent ovarian stimulation for IVF. INTERVENTION: Leuprolide acetate was combined with hMG and FSH for ovarian stimulation. MAIN OUTCOME MEASURE: Follicular fluid aspirates were collected and oocytes were recovered 34 to 36 hours after hCG injection. The patients proceeded to undergo IVF and ET. Follicular fluid hormones were measured using standard RIA. Angiotensin II and steroid hormone concentrations in FF were compared for pregnant versus nonpregnant women using the Student's t-test and rank-sum test. Pearson multiple-correlation analysis was performed to calculate correlation coefficients among AII concentrations and steroid concentrations in FF aspirates. RESULTS: Mean FF concentration of AII was significantly lower in samples from women showing clinical pregnancies (112.2 +/- 13.9 pg/mL [107.3 +/- 13.3 pmol/L]) compared with samples from women who did not achieve pregnancy (217.1 +/- 23.8 pg/mL [207.5 +/- 22.7 pmol/L]) (mean +/- SE). A negative correlation was observed between FF concentrations of AII and P. Correlations of AII with E2, T, A, or with ratios of these did not show significance. CONCLUSION: These data suggest that high AII concentration at time of oocyte recovery may indicate poor pregnancy outcome in women undergoing ovarian stimulation for IVF. These data corroborate previous results in animal models showing that AII predisposes follicles to undergo atresia-like conditions.

Atrial natriuretic peptide: a chemoattractant of human spermatozoa by a guanylate cyclase-dependent pathway.

Atrial natriuretic peptide (ANP), found in mammalian ovarian granulosa cells and oocytes (Kim et al., 1992, 1993), induces the human acrosome reaction (Anderson et al., 1994). The purpose of the present study was to determine whether ANP, as egg-derived peptides from sea urchins, can act as a chemoattractant to human spermatozoa. Small lengths of capillary tubing that contained different concentrations of ANP were suspended over a suspension of washed spermatozoa. The number of spermatozoa that entered the tubing was determined. More than twice the number of spermatozoa moved into the tubing that contained a maximally effective concentration of ANP, as compared with tubing that contained only medium. The concentration of ANP that produced a half-maximal effect was 0.7 nM. The effect was blocked by LY83583, an inhibitor of guanylate cyclase. ANP produced more than a twofold increase in the rate of cGMP formation, an effect that was blocked by LY83583. Human ANP (5-27), a fragment of the intact peptide, had no chemoattractant activity. These findings suggest that a specific sperm receptor exists for the chemoattractant activity of ANP that is associated with guanylate cyclase. The chemoattractant activity of ANP is independent of the presence of extracellular calcium ions and is independent of the action of ANP as a stimulus of the acrosome reaction. There is no association between the chemoattractant activity of follicular fluid and the follicular fluid concentration of ANP. These data suggest that factors besides ANP are responsible for the chemoattractant activity of follicular fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of induced hyperprolactinemia on in vitro fertilization cycles.

OBJECTIVE: To investigate the effect of induced endogenous hyperprolactinemia on the luteinization process, as expressed by the shift in the P:E2 ratio after hCG injection in IVF cycles. PATIENTS AND INTERVENTIONS: Serum PRL, E2, and P levels were measured in 49 IVF patients (leuprolide acetate and hMG protocol) on the day of hCG injection. Estradiol and P also were measured on the day after hCG. Serum P:E2 ratios were calculated for two groups of patients; group I (control): PRL < or = 20 ng/mL (conversion factor to SI unit, 1.00); group II (hyperprolactinemia): PRL > 20 ng/mL. Estradiol and P also were measured in follicular fluid (FF) and the gamete performance was compared between groups. RESULTS: Data analysis showed no significant differences in the mean +/- SD serum peak E2 (pg/mL; conversion factor to SI unit, 3.671) between groups: group I, 1,769 +/- 843; group II, 2,333 +/- 1,194; the mean FF E2 (pg/mL) group I, 351 +/- 221; group II, 370 +/- 186; or the mean FF P (ng/mL; conversion factor to SI unit, 3.180) group I, 8,357 +/- 3,127; group II, 11,354 +/- 12,888. No significant differences were found between groups in the P:E2 ratios on days 1 or 2: group I, 78 +/- 48 and 209 +/- 137; group II, 70 +/- 47 and 224 +/- 197, respectively. The magnitude of the P shift also showed no significant difference between the two groups; the mean +/- SD shift in the P level was 2.9 +/- 2.2 for group I, and 4.3 +/- 5.1 for group II. The serum PRL level had no effect on the fertilization rate (60% for group I and 70% for group II) or on the pregnancy rate (17% for group I and 23% for group II). CONCLUSION: These findings suggest that mild endogenous hyperprolactinemia induced by ovarian stimulation does not affect granulosa cell luteinization and gamete performance in humans.

Human chorionic gonadotropin levels in conception cycles after uterine and tubal embryo transfer.

OBJECTIVE: To describe the rate of rise of beta-hCG levels in normal single gestations after uterine and tubal embryo transfer. DESIGN: A prospective study from 1991 through 1992 in which infertility patients who conceived after ovulation induction and ET were monitored with serum beta-hCG levels. SETTING: Infertility unit at Rush-Presbyterian-St. Luke's Medical Center in Chicago, Illinois. PATIENTS: Ninety-eight women conceived after ovarian stimulation and ET. This study included only patients who conceived after uterine ET (n = 12) and tubal ET (n = 25) and had an exponential rise of beta-hCG levels and sonographic evidence of an intrauterine gestation. RESULTS: The rate of rise of mean beta-hCG levels after ET preceded that of tubal ET by 24 hours until day 14 when the two approximate each other. CONCLUSION: There appears to be a unique interaction between the trophoblast and endometrial surface that may account for the early detection of beta-hCG after uterine versus tubal ET.

Atrial natriuretic peptide (ANP) as a stimulus of the human acrosome reaction and a component of ovarian follicular fluid: correlation of follicular ANP content with in vitro fertilization outcome.

Atrial natriuretic peptides (ANPs) from several species induced the human acrosome reaction. The maximal response was highest for human ANP (18.6% above unstimulated or baseline values) and decreased progressively for peptides derived from animals lower on the phylogenetic scale. ANP concentrations required for a half-maximal effect in noncapacitated spermatozoa ranged from 0.07 to 0.38 nM. ANP induced the acrosome reaction in capacitated spermatozoa, but the concentration required was higher than in noncapacitated cells. The response in noncapacitated spermatozoa was independent of added extracellular Ca2+ and was completely inhibited by 1 microM LY83583 (inhibits particulate guanylate cyclase). However, 10 microM N omega-nitro-L-arginine (inhibits soluble guanylate cyclase) had no effect. ANP (80 pM) and 3 microM 1,2-dihexanoyl-sn-glycerol each induced a nearly half-maximal acrosome reaction. Added in combination, they produced no increased response, suggesting antagonism. Follicular fluid had variable levels of immunoreactive ANP. Average ANP content was nearly zero in samples that contained no oocyte at the time of aspiration but was higher (6.9 pM; 90% confidence limits = 1.67-28.72 pM) in follicular fluid containing oocytes that did not fertilize in vitro. Highest concentrations of ANP were present in follicular fluid containing oocytes that fertilized in vitro (72.8 pM; 90% confidence limits = 38.1-139.1 pM). These data suggest that noncapacitated spermatozoa can acrosome react without added extracellular Ca2+ in response to an extracellular ligand. Also, human spermatozoa appear to contain receptors for ANP similar to those found in other cell types. The ANP content of follicular fluid might partly explain the ability of follicular fluid to induce the acrosome reaction.

Hormonal profiles of early gestations with abnormal karyotype.

OBJECTIVE: To describe the hormonal profiles of chromosomally abnormal pregnancies during the first trimester. DESIGN: A prospective study from 1984 through 1990 in which infertility patients who conceived were monitored weekly with serum E2, P, and beta-hCG levels. SETTING: The infertility practice at Rush-Presbyterian-St. Luke's Medical Center in Chicago, Illinois. PATIENTS: Study included 15 women who had dilatation and curettage for first trimester fetal losses with confirmed abnormal karyotype, 6 women with chromosomally normal male abortuses, and 60 consecutive women whose pregnancies yielded normal term infants. RESULTS: After natural conception, E2 demonstrated a moderate rise in both normal and chromosomally abnormal pregnancies to approximately 300 pg/mL by day 29 (6 weeks of gestation). In normal gestations, E2 continued a steady increase to exceed the level of 1,000 pg/mL by day 64 (11 weeks of gestation). In chromosomally abnormal pregnancies, the mean E2 plateaued and remained at approximately 200 pg/mL until fetal demise was noted. In stimulated conceptions, the rise of E2 was sharp and early (1,200 pg/mL by day 29); in normal pregnancies, E2 steadily increased to an average of 1,400 pg/mL by the end of the first trimester, whereas in karyotypically abnormal gestations, E2 declined to approximately 200 pg/mL by day 64. In pregnancies yielding a male abortus, a sharp decline and plateau at 800 pg/mL by day 56 (10 weeks of gestation) was observed. In both natural and stimulated normal pregnancies, hCG levels first demonstrated a linear rise, followed by a curvilinear increase from day 29 until day 56, with a peak of approximately 110,000 mIU/mL. The beta-hCG in chromosomally abnormal pregnancies, as well as in pregnancies yielding a male abortus, was characterized by a slow and gradual rise to a maximum of 40,000 mIU/mL, which remained relatively linear until day 64 when fetal demise was detected in all cases. Progesterone level data were excluded from analysis because of frequent P supplementation. CONCLUSIONS: There were significant differences in the hormonal profiles of chromosomally normal and abnormal pregnancies. Serial measurements of serum E2 and beta-hCG from the 6th week of gestation may be useful in predicting an abnormal karyotype sooner than other current diagnostic tests.

First pregnancies and livebirths from transfer of sodium alginate encapsulated embryos in a rodent model.

OBJECTIVE: To determine the effect of sodium alginate encapsulation of rodent embryos on in vitro embryonic cleavage rates, implantation rates, and livebirth rates, and to find the in vivo degradation time for the capsules. DESIGN: Studies were conducted using both CB6F1 mice and Golden Syrian hamsters. RESULTS: Capsules made with 3.0% sodium alginate degraded in vivo within 24 to 48 hours after transfer. In vitro embryonic cleavage of encapsulated embryos was not impaired, nor were implantation rates in CB6F1 mice. Finally, 8.6% of transferred encapsulated embryos resulted in livebirths. CONCLUSIONS: Encapsulation of rodent embryos in 3.0% sodium alginate is not detrimental to embryonic development, implantation rates, or fetal development. Because the capsule degrades within 48 hours after transfer, encapsulating embryos may be beneficial for human in vitro fertilization and embryo transfer.

Acrosin activity in human spermatozoa in relation to semen quality and in-vitro fertilization.

Acrosin, a sperm proteinase released during acrosomal exocytosis, facilitates penetration through the oocyte vestments. The purpose of this investigation was to determine if a correlation exists between the acrosin activity of ejaculated human spermatozoa, before motility enrichment techniques, and in-vitro fertilization (IVF) success using selected (glass wool or swim-up) spermatozoa. Since all the oocytes were retrieved from women receiving exogenous hormonal stimulation and a mixed population of mature and immature oocytes were encountered, only cases with > or = 50% mature oocytes were analysed. Under these conditions, the acrosin activity was significantly greater (P < 0.01) in the ejaculates in which spermatozoa ultimately fertilized > or = 70% of the mature oocytes, than in the ejaculates in which spermatozoa ultimately fertilized < 70% of the mature oocytes. Furthermore, a strong correlation (r = 0.962, P = 0.0001) was detected between pre-IVF acrosin activity and subsequent high (> or = 70%) IVF success. Acrosin activity from normozoospermic and oligo-asthenozoospermic men was also compared and was significantly (P < 0.01) higher for the normozoospermic group. These data suggest that measurement of acrosin activity may be a valuable clinical laboratory assay for assessing the sperm fertilizing potential and that low acrosin activity is associated with abnormal semen characteristics.