[Reproductive and developmental toxicity studies of taltirelin hydrate (3) teratogenicity study in rabbits by oral...

Teratogenicity study of taltirelin hydrate, a thyrotropin releasing hormone analogue, was carried out in Japanese white rabbits. Female rabbits were orally given taltirelin hydrate at a dose of 0 (control), 0.15, 1.5, or 15 mg/kg from day 6 to day 18 of gestation. Females were sacrificed on day 29 and their fetuses were examined. Neither death nor adverse effects on food consumption in dams were found in any dose groups. In the 15 mg/kg group, rapid breathing and decreased body weight gain in dams were temporally observed. No adverse effect of taltirelin hydrate on reproductive function was detected in any groups. In the fetal examination, taltirelin hydrate had no teratogenic, lethal, or growth retardation effects in any groups. These results show that the no-toxic dose levels of taltirelin hydrate are 1.5 mg/kg for general toxicity in dams, and 15 mg/kg for reproductive function of dams and for development of their offspring.