Biomedical subjects

G D Hodgen

Publications and source records attributed to G D Hodgen.

At least 55 records · Page 3Linked to original sources

PubMed1994

Existence of P2-purinoceptors on human and porcine granulosa cells.

This study examines the possible roles of extracellular purine nucleotides in regulating ovarian granulosa cell function. Using luteinized human (L-hGC) and porcine granulosa cells (PGC), we examined the effects of purine nucleotides on intracellular free Ca2+ concentrations ([Ca2+]i), and whether they have any effect on steroidogenesis and cell proliferation. L-hGC and PGC were responsive to ATP and ADP at concentrations ranging from 0.1-100 mumol/L in a dose-dependent manner. There was a difference between L-hGC and PGC in the rank orders of agonist potencies for stimulating [Ca2+]i; for L-hGC, UTP > ATP > ATP gamma s > ADP > AMPPNP >> AMP and adenosine; for PGC, 2-methylthio ADP (2-meS ADP) > ADP > ATP = ATP gamma s = UTP > AMPPNP >> AMP and adenosine. No apparent additivity between the responses elicited by UTP and the purine nucleotides (ATP and ADP) was shown in L-hGC. On the other hand, an apparent additive effect between the responses to ADP and UTP was shown on PGC. Furthermore, ATP was a competitive antagonist of the action of ADP on [Ca2+]i levels in PGC. ATP, ADP, and AMP as well as adenosine stimulated basal progesterone and estradiol secretion from L-hGC, however, UTP had no effect on steroidogenesis in L-hGC. On the other hand, purine nucleotides and UTP as well as adenosine inhibited progesterone and estradiol secretion on PGC. However, 2-meS ADP, the most potent agonist for P2T-purinoceptors, did not affect steroidogenesis in PGC. Purine nucleotides had no influence on cell proliferation of L-hGC and PGC. These results indicate the existence of P2U-purinoceptors on L-hGC and P2U- plus P2T-purinoceptors on PGC, and that the inhibitory effect of purine nucleotides on steroidogenesis in PGC is most likely due to A1-adenosine receptors and also P2U-purinoceptors.

Animals↗

PubMed1994

Cryopreservation of human prophase I oocytes collected from unstimulated follicles.

OBJECTIVE: To evaluate the cryopreservation of immature human oocytes obtained from unstimulated ovarian tissue. DESIGN: Immature prophase I oocytes were obtained from unstimulated follicles and were either cryopreserved or cultured as controls. Cryopreservation was performed in a programmable freezing machine using one of two protocols. Method I (n = 133) used a one-step addition of cryoprotectant followed by a slow freeze and thaw protocol. With method II (n = 95), the cryoprotectant was added in a stepwise manner with cryopreservation performed in the presence of 0.2 M sucrose followed by rapid freezing and thawing. SETTING: Basic research center at a medical school. PATIENTS: Patients undergoing oophorectomy for nonovarian pathology. MAIN OUTCOME MEASURES: Rates of survival and maturation to metaphase II were compared between control oocytes and oocytes cryopreserved with methods I and II. RESULTS: With method I, a survival rate of 15.6% was obtained with 58.3% of surviving oocytes reaching metaphase II after culture compared with 50.0% of nonfrozen control oocytes. Method II produced a survival rate of 43.3% with 27.3% maturing to metaphase II. Maturation of control oocytes for method II was 46.4%. Although the survival rate with method II was significantly higher than with method I, the rate of in vitro maturation to metaphase II showed no difference. CONCLUSIONS: These results demonstrate that human prophase I oocytes obtained from unstimulated antral follicles are capable of meiotic maturation after cryopreservation.

Cell Survival↗

PubMed1993

The specificity of human spermatozoa/zona pellucida interaction under hemizona assay conditions.

The objective of this prospective study was to evaluate the specificity of human sperm/zona pellucida interaction under hemizona assay (HZA) conditions in experiments with gametes from the same and different species. Human, cynomolgus monkey and hamster oocytes were used after salt-storage. Oocytes were bisected into matching hemizonae by micromanipulation and used in the HZA. Semen was obtained from healthy men (donors) and male cynomolgus monkeys and prepared by wash and swim-up. Sperm binding to matching hemizonae was assessed (tight binding) after 4-h coincubation in the HZA in homologous and interspecies experiments. Acrosome reaction was evaluated in the sperm droplets using FITC-PSA and on the hemizonae using the T-6 monoclonal antibody. On human hemizonae, the number of tightly bound sperm for human and monkey were 93.2 +/- 15.8 and 3.9 +/- 1.3, respectively (P < 0.001). On monkey hemizonae, the number of tightly bound sperm for monkey and human were 126.0 +/- 34.8 and 2.8 +/- 1.6, (P = 0.02) respectively. On hamster hemizonae, there was negligible binding of human and monkey sperm. There was a significantly higher incidence of acrosome reacted sperm on the zona pellucida in homologous compared to heterologous experiments. These results demonstrate a high species-specificity of human gamete functions under HZA conditions, providing further support for the use of this bioassay in infertility and contraception testing.

Acrosome↗

PubMed1993

Validation of the hemizona assay (HZA) in a monkey model. II. Kinetics of binding and influence of cryopreserved-thawed spermatozoa.

We compared fresh and frozen-thawed cynomolgus monkey spermatozoa tight binding to the zona pellucida under hemizona assay (HZA) conditions. Monkey oocytes were recovered after superovulation and stored in salt solution. Matching hemizonae were obtained by micromanipulation. Semen, obtained by electroejaculation, was used fresh or was cyropreserved, thawed, and washed by swim-up separation. At the standard initial dilution of 500,000 motile sperm/ml (or 5 x 10(4) motile sperm/hemizona), binding was significantly higher for fresh sperm (P = 0.00004). For frozen-thawed samples, there was a linear increase in the number of tightly bound sperm with increasing sperm concentration (r = 0.95). At 1.5 x 10(6) motile sperm/hemizona, binding of frozen-thawed spermatozoa was similar to that of fresh at a standard concentration. Kinetic studies showed peak binding at 1 hr of gametes coincubation. We conclude that, in this monkey model, the HZA is a valuable bioassay for evaluation of sperm binding to the zona pellucida, the initial requisite for fertilization and embryo development.

Animals↗

PubMed1993

Fucoidin binding activity and its localization on human spermatozoa.

We previously reported that fucoidin (a polymer of predominantly sulfated L-fucose) significantly inhibits: (1) tight binding of human sperm to human zona pellucida in vitro and (2) stimulation of the acrosome reaction by acid solubilized human zona pellucida. Here, we determined fucoidin binding activity on human spermatozoa and its localization on both live and permeabilized human sperm populations. A typical binding curve was demonstrated with biotinylated fucoidin. In competitive inhibition assays with unlabelled fucoidin or human sperm membrane extracts, IC50's were 4.0 micrograms/ml and 31.4 micrograms/ml, respectively. Fucoidin binding was localized over the acrosomal region of methanol-fixed human sperm and this pattern of binding significantly decreased from 92 +/- 3% to 74 +/- 6% with calcium ionophore A23187 treatment (p < 0.01). Binding of fucoidin-coated beads to live (non-permeabilized) human sperm was less than 1%. Addition of the detergent, Triton-X, to permeabilize sperm membranes resulted in a significant increase in binding (p = 0.001). These results provide evidence for the presence of a fucoidin binding compound in human spermatozoa that is localized to the membranes of the acrosomal region and can be extracted by a mild detergent extraction. Absence of binding by fucoidin to intact but not permeabilized spermatozoa suggests that the heteropolysaccharide binds to a receptor within the acrosomal matrix. However, further investigation is warranted to determine whether a fucoidin binding site is present both at the sperm's surface for the initial contact with the zona pellucida, and also for secondary binding after exposure of the acrosomal membranes.

Acrosome↗

PubMed1993

The hemizona assay: its role in identifying male factor infertility in assisted reproduction.

OBJECTIVES: To identify male factor infertility among a group of patients in an assisted reproductive program (phase 1) and to evaluate the hemizona assay (HZA) in the diagnosis and prognosis of such a program (phase 2). DESIGN: The IVF performance of normal gametes in the Tygerberg program were critically evaluated. Female patients were classified as pure tubal factor infertility, having a normal FSH:LH ratio on day 3 of the menstrual cycle. All participating women produced three or more preovulatory oocytes at retrieval and were inseminated with sperm considered normal by all present diagnostic criteria. The total and normal fertilization rate thresholds were defined in that group. Using those thresholds, couples tested for sperm binding in the HZA (n = 48) were used and divided into two groups according to their fertilization rates, namely group 1, low fertilization (< 55%) and group 2, normal fertilization (> 55%). SETTING: University-based tertiary care center. PATIENTS: Ninety-nine couples (589 oocytes) with pure tubal factor infertility and normal male factor were used in phase 1. Forty-eight couples with normal and abnormal male factors that had both HZA performed and IVF treatment were included in phase 2. RESULTS: Investigation of the performance of normal gametes in 99 couples (589 oocytes) revealed the total fertilization rate (total number of oocytes fertilized/total number of oocytes inseminated) was (mean +/- SD) 88.6% +/- 16.8% and the normal fertilization rate (total number of oocytes with normal fertilization/total number of oocytes inseminated) was 81.3% +/- 22%. The minimum total fertilization rate that can be considered normal in the Tygerberg program using mean--2 SD is therefore 55% and for normal fertilization rate is 37%. The group with low fertilization rate (< 55%) showed a mean hemizona index (HZI) significantly lower; nevertheless, the distribution overlapping indicates a low discriminating power of the HZA. A sensitivity of 75% and a specificity of 75% were found; the positive and negative predictive values were 81% and 68%, respectively. CONCLUSIONS: The results indicated the HZA and HZI contribute important information and can serve in conjunction with other semen characteristics as useful tools during the diagnosis of the male factor in assisted reproduction.

Chorionic Gonadotropin↗

PubMed1993

Management of pituitary gonadal function via gonadotrophin releasing hormone (GnRH) antagonists, including ovulation induction by co-administration of either gonadotrophins or pulsatile GnRH.

GnRH agonists are now familiar clinical agents and are often the drugs of choice for suppression of the pituitary gonadal axis as part of various clinical indications. GnRH antagonists, which are likely to become clinically available soon, offer several advantages over the currently available GnRH agonists for many applications including ovulation induction. Here, we review the results from a series of pre-clinical studies designed to evaluate the potential clinical utility of this new class of compounds for ovulation induction protocols.

Female↗

PubMed1993

Progesterone antagonist RU 486 accommodates but does not induce labour and delivery in primates.

The hormonal mechanisms of parturition in primates remain controversial. Even so, the well-known decrease of plasma progesterone concentration near term is considered by many as the 'labour inducer'. The progesterone antagonist RU 486, which blocks progesterone activity at the cellular receptor level, appears to be a useful hormonal tool by which to study this tissue. Here, we tested its capacity to induce labour and delivery. A total of 23 Cynomolgus monkeys (Macaca fascicularis), within 9-17 days of expected term, were assigned to four different protocols to study various doses, routes and regimens of RU 486 administration. Observations included uterine contractile patterns, pharmacokinetics of RU 486 in plasma and passage of RU 486 into breast milk. None of the protocols tested successfully induced labour resulting in vaginal delivery within 24 h. Instead, the data demonstrate that blockade of progesterone activity by the progesterone antagonist was not sufficient by itself to achieve parturition in these primates. Uterine myometrial contractile activity under RU 486 exposure was not sufficient to induce labour and delivery. Moreover, the progesterone antagonist concentration in breast milk was very low, indicating little passage to suckling newborn infants.

Animals↗

PubMed1993

The ability of the hemizona assay to predict human fertilization in different and consecutive in-vitro fertilization cycles.

The objective of this prospective study was to examine the ability of the hemizona assay (HZA) to predict fertilization outcome of mature, pre-ovulatory oocytes under in-vitro fertilization (IVF) conditions. Since a large number of patients were evaluated over a long period, the power of the HZA to prognosticate fertilization results in the same and subsequent (consecutive) IVF cycles of those same patients was assessed. For IVF, only metaphase II oocytes were used. For the HZA, both fresh oocytes donated by patients at the time of IVF and oocytes recovered from surgically removed ovarian tissue (and salt-stored) were used, and bisected by micromanipulation techniques. Matching hemizonae were co-incubated either with spermatozoa from the patient (test) or from a fertile man (control) for 4 h. The number of spermatozoa tightly bound to the zona was counted. Patients (n = 112) were divided into two groups based on HZA results (expressed as HZA index or HZI): HZI > or = 30% (n = 72) and < 30% (n = 40). The patients with HZI < 30% had significantly lower fertilization rates in both the HZA-IVF cycle and in subsequent cycles compared to patients with HZI > or = 30% (P < 0.03). Linear discriminant analysis indicated the HZA to have a sensitivity of 84%, and positive and negative predictive values of 85 and 70% respectively, for prediction of fertilization outcome in a total of 233 cycles. It was concluded that the HZA is a good predictor of fertilization rate in vitro, and can be used in the IVF setting to supply additional clinical information in male-factor patients.

Female↗

PubMed1993

Functional and morphological features of spermatozoa microaspirated from the epididymal regions of cynomolgus monkeys (Macaca fascicularis).

In most species examined to date, spermatozoa mature during transit through the epididymis to become functionally competent to swim progressively, fertilize oocytes, and produce viable offspring. In the studies presented here, the status of spermatozoa obtained from the regions of the epididymis of the cynomolgus monkey (Macaca fascicularis) was examined. Epididymal fluid was collected by microaspiration from the caput, corpus, and cauda regions. The spermatozoa obtained were evaluated for morphology, motion parameters, and tight zona pellucida binding and were compared to spermatozoa collected by electroejaculation. Epididymal and ejaculated sperm differed morphologically only in the location of the cytoplasmic droplet. Motile sperm recovered by swim-up procedure exhibited a significantly higher proportion of sperm with more distal cytoplasmic droplets than the original aspirated samples (p < 0.02). Poor duration of movement was most noticeable for corpus spermatozoa, and to a lesser degree for cauda spermatozoa, when the motion parameters of velocity, linearity, and amplitude of the lateral head were examined. Zona pellucida binding was decreased only for sperm microaspirated from the caput region; sperm obtained from the corpus and cauda regions bound comparably to those collected via electroejaculation. These results suggest that by the time cynomolgus sperm reach the corpus region of the epididymis, they are functionally competent for tight zona binding. However, these nonhuman primate sperm may not complete the metabolic changes requisite for sustained sperm motility until reaching the most distal regions of the epididymis.

Animals↗

PubMed1993

Hypothalamo-anterior pituitary gonadotropin-releasing hormone and substance-P systems during the 17 beta-estradiol-induced plasma luteinizing hormone surge in the ovariectomized female monkey.

The present study examined the effects of 17 beta-estradiol benzoate (E2B) on the hypothalamic (HT) and anterior pituitary (AP) content of GnRH precursor (pro-GnRH-GAP), GnRH, GnRH-associated peptide (GAP), and substance-P (SP) during the various phases of the E2B-induced LH surge in cynomolgus monkeys. Changes in GnRH and GnRH-associated peptide (GAP) at both hypothalamic and AP levels were closely related at all times after E2B treatment. However, the pattern of change in the AP was very different from that in the HT. In the HT, pro-GnRH-GAP levels did not change significantly throughout the experimental period. In the AP, the pro-GnRH-GAP increased 48 h post-E2B treatment, the time of initiation of the LH surge. An 8-fold increase in AP GnRH occurred 30 h post-E2B treatment. There were no significant changes in the HT content of SP at any time after E2B treatment. However, there was a depletion of AP content by 48 h post-E2B, the time of the LH surge. These results demonstrate that E2 activates and deactivates in a coordinated manner the GnRH and SP systems of the HT-AP complex during initiation of the E2-induced LH surge. The observation that more significant changes occur in the AP than in the HT suggests that an important component of the E2 effect in inducing the LH surge may be directly at the AP level. This action involves changes in the contents of GnRH and SP in the AP.

Animals↗

PubMed1993

The absorption of oral micronized progesterone: the effect of food, dose proportionality, and comparison with intramuscular progesterone.

OBJECTIVES: To examine the effects of food ingestion and administered dose on the absorption of oral micronized P (Utrogestan; Besins-Iscovesco, Paris, France) and to compare the bioavailability of intramuscular versus oral routes of administration. DESIGN: Prospective, randomized, open label crossover protocol with 7 days between dosages. SETTING: Academic institution. PARTICIPANTS: Fifteen normal postmenopausal women. INTERVENTIONS: All subjects participated in three separate protocols: [1] micronized P (200 mg) or placebo under fasting or nonfasting conditions once daily for 5 days; [2] micronized P (100, 200, or 300 mg) once daily under fasting conditions for 5 days; and [3] micronized P (200 mg) or intramuscular P (50 mg in oil) administered once daily for 2 days. MAIN OUTCOME MEASURES: Serum P concentrations were measured in all groups. RESULTS: Concomitant food ingestion increased the area under the serum P concentration versus time curve (AUC0 to 24) and the maximum serum P concentration (Cmax) without affecting time to maximum serum concentration (Tmax) (P < 0.05). Micronized P absorption and elimination were first-order processes and exhibited dose-independent pharmacokinetics between 100 and 300 mg. After intramuscular P, Cmax was higher and Tmax occurred later compared with the oral P preparation. Oral P had lower relative bioavailability (8.6%) than intramuscular P. CONCLUSIONS: Absorption of micronized P was enhanced twofold in the presence of food. Both absorption and elimination were dose-independent, dose proportionality being confirmed. Bioavailability of the oral P was approximately 10% compared with intramuscular P.

Administration, Oral↗

PubMed1992

Primary culture of human fallopian tube epithelial cells and co-culture of early mouse pre-embryos.

We have established a monolayer culture system for human fallopian tube epithelial cells. The cells were isolated from tubes using collagenase digestion, and were cultured in Ham's F-10 supplemented with 15% fetal calf serum. The epithelial cells derived from culture were characterized using immunocytochemical staining and electron microscopy. These cells were stained with antikeratin and anti-epithelial membrane antigen, but showed no staining after treatment with antivimentin. Electron microscopy showed many microvilli on the cell surface and tight junctions or desmosomes at areas of cell-cell contact. Cell proliferation was enhanced by epidermal growth factor, but not by fibroblast growth factor, insulin, transferrin, estradiol-17 beta, or progesterone. The 2-cell ICR mouse pre-embryos were co-cultured for 4 days with tubal epithelial cells (A) (n = 98), in cell-conditioned medium (B) (n = 83), or in medium alone (C) (n = 72). During the first 24 h in culture, for groups A and B, the rates of cleavage to the 4-cell stage were 90.9% and 81.9%, respectively. Cleavage rates in these two groups were significantly higher (P = 0.0012, P less than 0.00001) than in group C (56.9%). After 72 h in culture, the rates of development to the blastocyst stage were significantly higher for groups A and B compared to group C (89.6% and 73.5% vs. 54.5%, P less than 0.00001, P = 0.0002). These results suggest that factor(s) from tubal epithelial cells may facilitate the development of mouse pre-embryos throughout the pre-implantation stages.

Animals↗

PubMed1992

Monoclonal antibody AG7 inhibits fertilization post sperm-zona binding.

Monoclonal antibodies (mAbs) against sperm cells are currently being used in an effort to define spermatozoal antigens involved in the fertilization process. We have produced a number of anti-human sperm mAbs by immunization of female mice with the 100,000 x g supernatant of octylglycoside-solubilized washed human sperm. From a panel of mAbs, 1 antibody, AG7, was selected and characterized due to its fertilization-inhibiting characteristics. MAb AG7 defines a sperm acrosome antigen-1 (SAA-1) located in the acrosomal region of human sperm as evaluated by indirect immunofluorescence. Staining of life sperm cells indicated that the antigen is present on the sperm surface. SAA-1 was also found on sperm of several other mammalian species, implying evolutionary conservation of the antigen. SAA-1 was first observed on testicular sperm and can be followed through epididymal transit, ejaculation, and capacitation. When applied in a mouse in vitro fertilization assay, mAb AG7 inhibits fertilization by greater than 95%, and inhibition is dose dependent, with half-maximal inhibition at 0.8 micrograms/ml. The block to fertilization could not be attributed to sperm agglutination, inhibition of motility, interference with adhesion to the zona pellucida, or inhibition of fusion with the oocyte membrane. MAb AG7 was demonstrated to inhibit calcium influx in spermatozoa in vitro (measured using the fluorescent indicator fura 2), a prerequisite for the acrosome reaction. Initial biochemical characterization of the antigen suggests it is proteinlike in nature, with a molecular weight of approximately 220 kD. The results suggest that SAA-1, identified by mAb AG7, is a sperm antigen crucially involved in the fertilization process, possibly an atypical steroid receptor or ion channel located within the sperm plasma membrane.

Acrosome↗

PubMed1992

Prediction of fertilization in vitro with human gametes: is there a litmus test?

OBJECTIVES: The objectives of this study were as follows: (1) to evaluate the relationships between sperm concentration, morphologic pattern, motion parameters, and sperm-zona pellucida binding capacity and (2) to assess their ability to predict fertilization outcome under in vitro fertilization conditions. STUDY DESIGN: Semen samples from 44 infertile men were prospectively evaluated for density, morphologic pattern (strict criteria), computerized motion parameters (motility, velocity, and linearity), and hemizona assay (outcome expressed as hemizona assay index), and results were correlated with fertilization outcomes of preovulatory oocytes during in vitro fertilization. RESULTS: Of all sperm parameters, morphologic pattern was the best predictor of the ability of the sperm to bind to the zona pellucida. Hemizona assay index was the best predictor of fertilization rate. Stepwise regression analysis provided a model of hemizona assay index plus motility with highest predictability (R2 = 53.4%). CONCLUSIONS: (1) The influence of sperm morphologic pattern as a prognosticator of fertilization outcome is established in major part as a determinant of sperm binding ability to the zona pellucida; (2) the hemizona assay provides a robust index that is highly predictive of the potential of human gametes to achieve fertilization and highlights its use in infertility and contraception testing.

Cluster Analysis↗

PubMed1992

Antide bioavailability: single dose administration for suppression of testosterone and inhibin in male monkeys.

The pharmacokinetics and pharmacodynamics of a single sc injection of Antide on testosterone (T) and inhibin secretion in intact male cynomolgus monkeys were examined. Fifteen primates were randomized to three groups receiving: propylene glycol and water vehicle, 3 mg/kg Antide, and 10 mg/kg of Antide. Antide at the 10 mg/kg dose caused long-term suppression of T ranging from 24-56 days. At the 3 mg/kg dose, suppression of T was of shorter duration. Serum Antide levels were significantly greater in the 10 mg/kg group than the 3 mg/kg group (p less than 0.02), both initially and through 35 days post-treatment. The duration of testosterone inhibition and sustained Antide levels were significantly correlated (p less than 0.01). Inhibin concentrations followed the same general pattern as testosterone reaching a nadir on day 21 post-treatment before subsequent recovery. The prolonged suppressive effect of Antide on T without detectable side effects makes this compound an excellent candidate for clinical evaluation.

Animals↗

PubMed1992

GnRH antagonists suppress prolactin release in non-human primates.

GnRH antagonists, such as Antide, are being evaluated for potential contraceptive applications. Although their contraceptive efficacy clearly results from their rapid inhibitory effects on gonadotropin release, there remains the possibility of other incidental effects. Under certain physiological conditions, the release of prolactin (Prl) appears to be temporally related to the secretion of luteinizing hormone (LH) and hence by inference to the secretion of GnRH. Here, we examined the effects of the GnRH antagonist Antide on the release of LH and Prl. Under agonadal conditions, a remarkable concordance was seen between LH and Prl pulses with up to 100% of pulses being coincident. Administration of Antide resulted in a rapid parallel decline in both LH and Prl with LH levels falling by 50% within 2 h and Prl levels falling by 30-40%. At this dose of Antide (1.0 mg/kg, sc), pulsatile release of LH and Prl continued albeit at a much reduced amplitude. The administration of a bolus of exogenous GnRH in the face of GnRHant-induced suppression resulted in prompt release of LH and Prl in all 3 monkeys. Since Antide inhibits the release of LH and Prl in a parallel fashion, and GnRH re-stimulates the release of both hormones in a parallel fashion, we conclude that the synchronous pulsatile release of LH and Prl observed in the agonadal monkey is due to a direct action of GnRH. What this action is for Prl release, and how it relates to the control of dopamine or other neuroendocrine mechanisms normally controlling the release of Prl remains unclear. It also remains to be seen whether this GnRH antagonist-induced suppression of Prl will have physiologic significance.

Animals↗

PubMed1992

Preclinical models for human pre-embryo biopsy and genetic diagnosis. I. Efficiency and normalcy of mouse pre-embryo development after different biopsy techniques.

OBJECTIVE: To compare the usefulness of three micromanipulative methods at two different stages of pre-embryo development and to assess possible effects on postbiopsy survival and development. DESIGN: Four-cell and eight-cell mouse pre-embryos were biopsied using enucleation, aspiration, or extrusion of single blastomeres. After biopsy, pre-embryos were observed for in vitro and in vivo development. SETTING: Laboratories of The Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School. PATIENTS, PARTICIPANTS: Only mice were used. INTERVENTIONS: Pre-embryo biopsy, developmental normalcy and pre-embryo transfer were studied. MAIN OUTCOME MEASURE(S): Few pre-embryos died as a result of biopsy trauma. High postbiopsy survival rates were associated with normal intrauterine and postnatal development. RESULTS: Expanded blastocyst formation rates from four-cell and eight-cell pre-embryos were 94.6%, 96.7% (controls); 80.7%, 89.1% (enucleation); 90.1%, 91.7% (aspiration); 83.1%, 91.5% (extrusion), respectively. Live birth rates at the four-cell stage were slightly lower in the enucleation group than in the blastomere aspiration and extrusion groups or controls (49.2% versus 58.8%, 56.3% and 66.7%, respectively). For the eight-cell stage, there were no differences between the groups. No developmental abnormalities were found in body or organ weights, in neonates or at 3 weeks of age, or in their subsequent ability to reproduce a second generation. CONCLUSIONS: Biopsy of mouse pre-embryos produces only a small loss of viability because of trauma and permits normal prenatal and postnatal development among surviving pre-embryos.

Animals↗