Experimental evidence for failure to implant as a mechanism of infertility associated with endometriosis.

The effect of endometriosis on pregnancy, from ovulation through day 14 of pregnancy, was studied in an animal model previously developed and validated with the use of the rabbit. Endometrial tissue was implanted surgically in rabbits and allowed to grow for 11 weeks without hormonal supplementation. The animals were artificially inseminated with semen from bucks with established fertility and human chorionic gonadotropin was administered to induce ovulation.

Influence of ovarian steroids on prostaglandin- and leukotriene-induced uterine contractions.

The mammalian uterus is capable of metabolizing arachidonic acid via the lipoxygenase pathway, and the uterus responds to lipoxygenase products. We postulated that progesterone influences the production of leukotrienes in the uterus in a way similar to that in which estradiol influences prostaglandin production. Uterine contractions were measured in actively sensitized guinea pigs throughout the estrous cycle and in ovariectomized, hormonally primed, sensitized guinea pigs.

Development of an animal model for quantitatively evaluating effects of drugs on endometriosis.

The present study was conducted to induce endometriosis in an experimental animal model in which the condition and its response to pharmacologic agents could be quantified. Endometriosis was induced in New Zealand White rabbits by transplanting endometrial sections into various sites throughout the peritoneum. After 7 weeks, the mean implant weight increased in concomitant controls from 10.

Inhibin activity and steroid hormone levels in ovarian extracts and ovarian vein plasma of female monkeys during postnatal development.

Inhibin activity, follicle-stimulating hormone (FSH)-suppressing substance, estrogen, progesterone, and androstenedione were measured in charcoal-treated ovarian tissue and ovarian venous and peripheral blood of eight rhesus monkeys ranging from 12 to 48 months of age. All of the monkeys demonstrated inhibin activity in ovarian tissue, which, if expressed per milligram protein, was relatively constant throughout development. However, if the activity was expressed per ovary, the amount of ovarian FSH-suppressing substance increased between 26 and 48 months; it was present in detectable amounts in ovarian venous blood only in one 26-month-old monkey.

Involvement of lipoxygenase products in myometrial contractions.

Studies with an in situ preparation of guinea pig uterus suggest the possible involvement of the lipoxygenase pathway of arachidonic acid (AA) metabolism in myometrial contractions. Female guinea pigs were sensitized to ovalbumin (OA) on day one of their estrous cycle. On day 14, these pigs were anesthetized and the uterus was cannulated for measuring contractions.