Symposium: reproduction in baboons. Some reproductive studies in the baboon

A captive colony of baboons has been used for three decadesfor various reproductive studies where application of findingsto human therapeutics was desired. The characteristics of themenstrual cycle in baboons are very similar to those of women,except that of the baboon is slightly longer and there is alower luteal phase concentration of oestradiol. The durationof pregnancy in baboons is about two-thirds that of humans butpatterns of oestrogen and progesterone secretion are virtuallyidentical. The principal oestrogen produced by the pregnantbaboon is oestrone, while oestriol is the most abundant in humanpregnancies. Chorionic gonadotrophin (CG) is elevated significantlyonly in the first trimester of a baboon pregnancy, while humanpregnancy concentrations of this hormone are about one-thirdof the first trimester level in the second and third trimesters.Breeding success of baboons in captivity depends on care beingtaken to cull infertile animals from the colony prior to commencingmatings. Under optimal conditions, fertility rates can reachnearly 80%. Female baboons have been successfully used to gaininsights into antifertility effects of contraceptive vaccinesdirected against CG, spermatozoa and ovum antigens. Extensiveuse of the colony for developing a human chorionic gonadotrophin(HCG) antifertility vaccine has been invaluable for progressin this field. Other pharmaceuticals and devices have been successfullytested in baboons, but costs and mandated regulations for themanagement of these non human primates have made their currentuse in meaningful studies extremely difficult.