The effects of the administration of fenoprofen or indomethacin to rat dams during late pregnancy, with special reference to the ductus arteriosus of the fetuses and neonates

Teratological evaluation of a novel antiabortifacient, dibenzyloxyindanpropionic acid. II. Postnatal morphological and behavioral development

Dibenzyloxyindanpropionic acid (DIPA) is an antiabortifacient prostaglandin F2 alpha antagonist. Significant protection against prostaglandin F2 alpha-induced abortion in Charles River CD-1 mice is afforded by 50 mg/kg DIPA, administered intramuscularly twice daily from day-15 of gestation, two days prior to prostaglandin F2 alpha challenge. Furthermore, treatment of CD-1 mice with 50 mg/kg DIPA intramuscularly daily throughout gestation or with 50 or 200 mg/kg twice daily only on day-15 of pregnancy, revealed no structural teratological effects nor histopathological anomalies in the offspring. The present behavioral teratological investigation demonstrates that prenatal treatment of CD-1 mice with 50 mg/kg DIPA intramuscularly daily throughout gestation does not adversely affect postnatal morphological development (offspring viability; weight gain; timing of bilateral pinna detachment, eye opening, eruption of mandibular and maxillary incisors, appearance of mamillary ridges, vaginal opening, testicular descent, and appearance of downy fur), postnatal behavioral development (vocalization; auditory startle reflex; corneal reflex; righting reflex and subsequent air righting; cliff avoidance; limb placing response and grip strength; motor coordination; olfactory orientation; locomotion; motor activity; homing instinct; and acquisition and retention of an active avoidance task), or fertility of the progeny. It is concluded that DIPA is an effective and safe antiabortifacient in mice at the doses tested.

Teratological evaluation of a novel antiabortifacient, dibenzyloxyindanpropionic acid--I. Dysmorphological and histopathological studies

Dibenzyloxyindanpropionic acid (DIPA) is an anti-abortifacient prostaglandin F2 alpha(PGF2 alpha) antagonist. Significant protection against PGF2 alpha-induced abortion in Charles River CD-1 mice is afforded by 50 mg/kg DIPA, administered i.m. twice daily from day-15 of gestation; two days prior to PGF2 alpha challenge. In the present teratological evaluation, CD-1 mice were treated either daily throughout gestation with 50 mg/kg DIPA i.m., or only on day-15 of gestation with two doses each of 50 or 200 mg/kg DIPA i.m. Controls received saline injections. Some dams were delivered by cesarian section on day-19 of gestation, while others were allowed to deliver spontaneously at term. Parameters monitored in the offspring were litter sizes, body weights, sex ratios, viability of progeny, external malformations, cleft palate, skeletal anomalies, patency (prenatal) and closure (postnatal) of the ductus arteriosus, gross anatomy of organs, and histopathological examination of tissues. Consistent with a PGF2 alpha antagonistic mechanism of action, DIPA treatment throughout gestation prolonged pregnancy to the upper normal limit. Prenatal administration of DIPA increased the pseudopregnancy rate, but none of the treatment schedules produced any recognizable teratogenic effects.

Antiabortifacient action of dibenzyloxyindanpropionic acid in mice

DIPA [5,6-bis(dibenzyloxy)-1-oxo-2-propyl-2-indanpropionic acid] was evaluated for its antiabortifacient action in mice. PGF2 alpha administered intramuscularly twice daily at 525 micrograms/kg per dose starting on day-17 of gestation resulted in premature delivery (prior to day-19 of gestation) in 55% of the animals. This constituted an ED50 abortifacient dosage schedule of PGF2 alpha. Intramuscular administration of DIPA at a dose of 50 mg/kg twice daily, starting on day-15 of gestation, protected the mice against the premature delivery induced by the ED50 dosage schedule of PGF2 alpha in that only 20% of the animals delivered prematurely. In saline-treated controls, none of the animals delivered prior to day-19 of gestation. Thus, DIPA appears to be an effective antiabortifacient agent.