Abstract
To assess the effects of test substances on reproductive functions and embryo-fetal development in cynomolgus monkeys (Macaca fascicularis), menstrual cycle and fetal/neonatal evaluation control data are particularly important. Menstrual cycles (146 female monkeys for a total of 907 cycles) were variable within and between females (average of all individual cycles: 30.5 ± 7.7 days, average of mean value of each female: 30.9 ± 4.5 days). Pregnancy ratio of 3-day mating session (for a total of 463 mating sessions) and the mean abortion/embryo-fetal death incidence (62 dams) were approximately 40% and 8%, respectively. In teratology studies, the mean fetal weight on GD100 was 115 g. There were no external fetal abnormalities, a low incidence of visceral (absence of left thyroid, 2.4%) and skeletal abnormalities (hemi-vertebra or absence of the 12th rib, 5.6%), and a 12.6% incidence of skeletal variations (lumbar ribs). Peripheral lymphocyte subsets (flow cytometry) analysis data indicate that the levels of CD45, CD8, CD3, and CD4 were lower in the fetus (GD100). CD8, CD3 and CD4 in neonates are essentially equivalent to the mothers values by 6 months after birth. CD3 and CD4 were increased as compared to mothers levels in the neonate. CD3 was approximately 30% higher while CD4 was 80% higher in the neonate. Both CD3 and CD4 decreased after the neonatal stage and approached the mothers levels at 6 months.
