Incorporation of a GnRH agonist, leuprolide acetate, into regimens with exogenous gonadotropins to produce ovarian stimulation and ovulation in the nonpregnant squirrel monkey.

This study was designed to measure the effects of variations in the length of pretreatment with a GnRH agonist, leuprolide acetate (LA), on subsequent follicular development and ovulation. The hypothesis was that the duration of LA suppression of pituitary function does not adversely affect ovarian response to standardized ovulation induction protocols in squirrel monkeys. The first phase determined the dose and duration of LA needed to achieve a hypogonadal state.

Cryopreservation of murine zygotes for use in testing culture environments.

Developing one-cell mouse zygotes are more sensitive to in vitro environmental conditions than are cleavage-stage embryos. However, for convenience and reproducibility, cryopreserved two-cell zygotes are routinely used for such assays. Concern over the possibility of inducing damage by exposing one-cell zygotes to cryoprotective agents and freeze-thaw procedures during syngamy led us to examine one-cell zygotes, with and without visible pronuclei, in an effort to minimize or avoid these effects and obtain the highest possible developmental rate.

Plasma membrane block to polyspermy in human oocytes and preimplantation embryos.

The existence and time course of the human plasma membrane block to polyspermy were investigated by an in vitro fertilization assay using zona pellucida-free unfertilized oocytes, pronuclear oocytes and embryos. In the time course study using a high sperm concentration (10(5) spermatozoa ml-1), the number of penetrating spermatozoa at 30 and 60 min after insemination were 1.3 +/- 0.

In vitro fertilization and the effect of progesterone and 17 alpha-hydroxyprogesterone on acrosome reaction of mouse epididymal spermatozoa.

This study assessed the effect of progesterone and 17 alpha-hydroxyprogesterone (17 alpha-OH-progesterone) at concentrations of 0.01-10 micrograms/ml, on the acrosome reaction and in vitro fertilizing ability of mouse epididymal spermatozoa. Cumulus masses containing oocytes were cultured in Brinster's medium, to which were added capacitated epididymal spermatozoa which had been incubated in medium with various concentrations of progesterone or 17 alpha-OH-progesterone for 90 min.

Reproductive toxicity of Aroclor-1254: effects on oocyte, spermatozoa, in vitro fertilization, and embryo development in the mouse.

Polychlorinated biphenyls (PCBs) have been reported to adversely affect reproduction in laboratory and wild animals. The present study was undertaken to determine the toxic potential of Aroclor-1254 (A-1254) on in vitro fertilizing ability of oocytes and epididymal sperm and on preimplantation embryo development in the mouse. A-1254 was added to the IVF medium at concentrations of 0.

The effects of polybrominated biphenyls and perchlorinated terphenyls on in vitro fertilization in the mouse.

Polybrominated biphenyls (PBBs) and perchlorinated terphenyls (PCTs) are industrial chemicals that are long-lasting environmental contaminants. Although in vivo effects of PBBs on reproduction are documented, no information is available on the effects of these chemicals on sperm-egg interactions or fertilization. The present study was undertaken to determine the toxic potential of PBBs and PCTs on in vitro fertilization (IVF) in the mouse.

Effects of polychlorinated biphenyls (PCBs) on in vitro fertilization in the mouse.

Polychlorinated biphenyls (PCBs) are industrial chemicals that are long-lasting global environmental contaminants. PCBs have been reported to adversely affect reproduction in laboratory and wild animals by reducing the incidence of breeding and the survival rate of young. The present study was undertaken to determine the toxic potential of PCBs on in vitro fertilization (IVF) in the mouse.

In vitro fertilization analysis of squirrel monkey oocytes produced by various follicular induction regimens and the incidence of triploidy.

An in vitro fertilization system utilizing squirrel monkeys was used to compare follicle-stimulating hormone, clomiphene citrate and prostaglandin E as follicular induction regimens, analyze culture medium characteristics, and examine the physiological phenomenon of polyspermy. Induction of follicular growth was poor with clomiphene citrate when compared to the control group and increased the incidence of atretic follicles at all levels tested. When prostaglandin E was administered, larger numbers of mature oocytes were recovered at laparoscopy.

Toxicology of maternally ingested trichloroethylene (TCE) on embryonal and fetal development in mice and of TCE metabolites on in vitro fertilization.

Trichloroethylene (TCE), an industrial solvent, is a soil and ground water contaminant found across the United States. The metabolism and carcinogenic potential of TCE have been studied extensively in the past 15 years yet there is little information on the chemical's possible effects on reproduction. No reference to the reproductive effects in mice of TCE by oral administration exists in the literature.

Effects of a DNA-specific fluorochrome, Hoechst 33258, on mouse sperm motility and fertilizing capacity.

DNA specific fluorochrome (Hoechst 33342 and 33258) as non-toxic stains, have been widely used to measure cell density and proliferation, detect sperm-egg fusion, and observe the development of pre-implantation embryos. It has been reported that Hoechst 33342 at a concentration of 10 micrograms ml-1 had significant inhibition on embryo cleavage. In this study, we incubated B6D2F1 mouse sperm and eggs with different concentrations of Hoechst 33258, 0, 1.

New method for in vivo recording of myometrial activity in the squirrel monkey, Saimiri sciureus.

Videolaparoscopy was used to visualize the reproductive tract contractility of the squirrel monkey, Saimiri sciureus. This technique gives information on the nature, direction of propagation, duration, and frequency of contractions. At the times of ovulation, and embryo entry to the uterus, contractile activity was observed in both the uterus and oviduct, with the latter being more frequent.

Cellular toxicity of toluene on mouse gamete cells and preimplantation embryos.

Toluene is an aromatic hydrocarbon, which has been used in the paint, lacquer and glue industry. It has been detected in municipal water supplies. Previous mouse in vivo studies indicated that toluene administrated by gavage increased the embryonic mortality.

Immunological response and ovarian histology of squirrel monkeys (Saimiri sciureus) immunized with porcine zona pellucida ZP3 (M = 55,000) macromolecules.

ZP3 (M, = 55,000) is the major electrophoretic component of the porcine zona pellucida (ZP). In a continuing assessment of ZP3 as a candidate antigen for contraceptive vaccine development, female squirrel monkeys were immunized with 200 μg ZP3 using either Freund's adjuvant (FA) or muramyl dipeptide (MDP) and the effect of such immunization on ovarian histology examined. Two experimental and three control groups were immunized: Group 1 (n = 4), ZP3 plus FA; Group 2 (n = 4),ZP3 plus MDP; and controls-Group 3 (n = 2), ZP3 alone; Group 4 (n = 4), FA alone; and Group 5 (n = 4), saline.

Microencapsulation of single, multiple, and zona pellucida-free mouse preimplantation embryos in sodium alginate and their development in vitro.

Preimplantation embryos obtained from immature superovulated B6D2F1 female mice were microencapsulated in sodium alginate singly, in multiples of 2 or 3, or denuded of their zona pellucida. Encapsulated embryos developed in vitro at a rate similar to control embryos. Development of zona pellucida-free embryos was significantly less than that of intact embryos, but there was no difference between encapsulated and non-encapsulated zona pellucida-free embryos.

In vitro fertilization in nonhuman primates.

Ovulation induction, sperm capacitation, and fertilization have been studied for over 50 years in nonhuman primates but it has only been in the past 20 years that extensive studies on sizeable numbers of embryos have been carried out. Of over 200 species of nonhuman primates only a few have been studied and the majority of the findings come from studies of the squirrel monkey, baboon, rhesus, and cynomolgus macaque. Nevertheless, the fertilization process appears to be similar to that identified in other mammals and in man.