[Reproductive and developmental toxicity studies of montirelin hydrate (3)--Teratogenicity study in rabbits by intravenous administration].

A study of the effect of montirelin hydrate (NS-3), a new drug for the treatment of disturbance of consciousness, during the period of organogenesis was conducted in New Zealand white rabbits. Female rabbits were given the drug intravenously at dose levels of 0 (control), 0.01, 0.1 and 1 mg/kg from day 6 to day 18 of pregnancy. Female rabbits were sacrificed on day 29 of pregnancy for examination of their fetuses. In the 0.1 mg/kg group, food consumption decreased slightly. In the 1 mg/kg group, tachypnea, salivation and rhinorrhea were observed, and body weight and food consumption decreased and water consumption increased. The drug had no effect on the number of corpora lutea and implantations, or on fetal mortality, on fetal body weights, on placental weight, on sex ratio, or on external, visceral and skeletal development of the fetuses. These results show that the NOAEL of montirelin hydrate are 0.1 mg/kg for general toxicity in mother animals, and 1 mg/kg for pregnancy of mother animals and for development of fetuses.