Biomedical subjects
Publications and source records attributed to W R Dukelow.
Mating trials were conducted with 16 adult female M. fascicularis that had been repeatedly laparoscoped. Eight of the females in this study conceived. Of these, six delivered live full-term infants after having had between 38 and 67 laparoscopies prior to conception.
Direct administration of 0.5 IU of human chorionic gonadotropin (HCG) into the matured ovarian follicles of adult female Saimiri sciureus resulted in ovulation in 45% of the animals treated. When purified ovine luteinizing hormone (LH) was administered, ovulation was observed in 55% of the animals while intrafollicular injection of saline had no effect. Similar injections of HCG into matured follicles of Macaca fascicularis would not cause ovulation but did result in a 55% increase in menstrual cycle length. These results indicate that the necessity of a primate source of LH for inducing ovulation may be due to an extrafollicular mechanism.
Studies were undertaken to characterize the basic behavioral parameters of a breeding colony of Macaca fascicularis under caged conditions. The female Reproduction Performance Index and the Success Ratio were found to correlate with mating behavior relating to cyclicity in females with cycles of less than 30 days. These evaluations proved to be useful in the selection of animals based on sexual vigor.
Synthetic TPAL, a polypeptide reported to occur naturally in hamster zygotes, was tested at doses of 3 or 18 microgram/day for antiovulatory activity in cyclic hamsters (for 4 days) and squirrel monkeys (for 5 days) induced to ovulate. The TPAL treatment did not alter the ovulatory response in hamsters or monkeys.
Semen was collected from adult male Macaca fascicularis using a rectal probe for electro-ejaculation. The effect on sperm motility of varying semen extender egg yolk concentration, pH, glycerol concentration, and equilibration times of sperm with glycerol was examined. No significant difference was observed between motilities at extender egg yolk concentrations of 10% to 40%. Progressive motility was significantly greater at pH 7.2 and 8.0 than at 5.8, 6.5, and 8.7 (p less than 0.05). Glycerol concentrations of 7% and 10% yielded optimum progressive motility after freezing. A 1-minute equilibration of semen in extender containing glycerol resulted in greater sperm motility after freezing than did equilibration for 25 or 45 minutes.
Exposure of Syrian hamsters for two twenty-minute periods at 40 degrees C on a single day of pregnancy (ranging from day 6 to day 13) resulted in differing teratogenic effects. Maximum resorption (52.6%) was seen with treatment on day 7 whereas the highest rate of malformation (51.9%) was observed with treatment on day 9. Cranial defects predominated with treatment early in pregnancy (highest incidence of day 9) while limb defects were not observed with any treatment administered before day 9. Exencephaly occurred with treatments on day 6 and 8, with a single case after treatment on day 10. Cleft lip and cleft palate were observed with treatment on days 9 and 10. These studies illustrate the usefulness of the Syrian hamsters in teratological studies and characterize some of effects exerted after mild heat treatment at varying stages of pregnancy.
A laparoscopic uterine flushing technique has been developed for the recovery of preimplantation embryos from the squirrel monkey. Fourteen adult female squirrel monkeys were induced to ovulate with 4 or 5 days' treatment with follicle-stimulating hormone (1 mg) followed by human chorionic gonadotropin (HCG) (500 IU). Natural mating with a fertile male or artificial insemination was performed near the time of ovulation. Thirty-six hours and eleven days after HCG administration, the females were laparoscoped to determine whether ovulation had occurred. Under laparoscopic control, 1.2 to 3 ml of warmed saline were flushed through the uterine lumen 4 to 7 and 15 to 17 days after HCG administration. Flushed fluid was recovered with a plyethylene catheter or a Pasteur pipette inserted into the cleaned vagina. Fifty-eight uterine flushings were performed, with an average of 65.4% fluid recovery. Six nonfertilized ova and two preimplantation blastocysts were recovered by this technique.
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A total of 595 menstrual cycles were studied in 28 adult M. fasicularis over a period of five years. Ovulations, observed laparoscopically in 138 cycles, occurred on the left ovary 62.6% of the time. No significant effect was noted on cycle length relative to the ovulatory status of the previous cycle or the occurrence of ovulation on the same ovary in consecutive cycles. Laparoscopy had no effect on the parameters studied.
A computer program was developed to maintain animal records for a nonhuman primate colony used in research. The program was designed for use with an existing laboratory notebook system. The computer program identifies each notebook entry containing information about each animal and keeps other information, including animal name, sex, species, projects to which the animal is assigned, location of the animal, dates and body weights. The program is interactive and easy to use. Information stored in the system is readily accessible to all investigators using the animals. In 17 months of use, 1382 master file entries were developed for 113 monkeys.
The techniques used for laparoscopic observation of reproductive systems in 23 species are described. The application of various techniques to biomedical research is examined, and the methods used for laparoscopic follicular aspiration and injection, as well as the techniques for uterine flushing collection from swine and nonhuman primates, and oviductal deposition of test solutions are described.
This study demonstrates the ability of Saimiri to adapt to out-of-door housing in a northern temperate climate from May through October, to ovulate (both naturally and in response to an induction regime), become pregnant, give birth, and to initiate lactation. The observations reported are of importance for the captive breeding of Saimiri for use in biomedical research.
Field observations on reproductive activity in the Panamanian tamarin (Saguinus oedipus geoffroyi) were made in conjunction with the examination of 131 reproductive tracts collected at regular intervals over one year. Reproductive tract characteristics were compared over seasons. Embryonic and fetal development were also assessed. A distinct birth peak was observed from April to early June. Pregnancies in April and May point to a potential, but unrealized, birth peak in August and September. Despite the tendency toward birth peaks, reproductive activity occurred throughout the year. Reproduction was limited to a single female per social group. The average number of infants born per female was two. Groups inhabiting lowland areas appeared to be more successful in raising young than groups inhabiting upland areas.
Progesterone and oestrone alone or in combination were administered to sows during early gestation. A dose of 25 mg progesterone and 12-5 mug oestrone injected together for 10,5 or 2 consecutive days during the implantation interval caused increased litter size at term.
Physiological responses and some aspects of reproductive function were examined in mated female pigs subjected to a short-term heat stress during two intervals of early gestation. Trial 1 control and treated animals experienced temperatures of 24.0 and 40.2 degrees C, respectively, from days 2 through 13 of pregnancy. Trial 2 control and treated pigs were exposed to 23.3 and 40.4 degrees C, respectively, from days 14 through 25 of pregnancy. Both high thermal exposures caused significant increases (P less than 0.05) in rectal temperature. At body temperatures of 41.1 degrees C or above, animals became more active and behavioral patterns erratic. Stressed pigs in both trials exhibited adaptation to the short-term high thermal environment as treatment days progressed. Embryonic mortality in the stressed animals in trial 1 was greater than in controls, with the animals in the former group retaining a normal size litter or losing the entire litter by day of slaughter. A significant proportion (P less than 0.01) of litters from stressed animals contained degenerating fetuses at day 42 of gestation, suggesting a continuous or delayed effect of thermal stress on embryo survival.
Captive squirrel monkeys show a seasonal response to a subtle ovulation induction regime of the five days of progesterone, four days FSH (1 mg/day) and a dose of HCG (500 IU), with the minimal response occurring from July to September. A 3 times 3 factorial design with 18 adult female monkeys was used to determine the effects of increasing doses of HCG (500, 1,000, OR 1,500 IU) and increasing dose of duration of FSH (1 mg for four days, 2 mg for four days, or 1 mg for five days) on ovulation between early July and mid-October. An increase in either dose or duration of FSH increased ovulation while increasing HCG was ineffective.
An in vitro fertilization system was developed for the squirrel monkey. Oocytes recovered from follicles of gonadotropin-treated females and cultured in vitro with spermatozoa resulted in fertilized ova capable of developing to the four-cell stage in culture. In total, 264 follicular oocytes were recovered from 922 follicles in 38 Saimiri sciureus. Seventy-nine developed to the first polar body stage, and 32 of the 79 were fertilized in vitro.