The goal of Project 29 is to obtain preliminary evidence for the development of a nonhuman primate model of polycystic ovarian syndrome (PCOS). The 4 monkeys used for the experiment had cycled consistently over the previous 12 months (12 or 13 menses recorded, at regular intervals). They were provided with an intraovarian graft of genetically modified baby hamster kidney cells, encapsulated in a polymer of poly [acrylonitrile vinyl chloride, P(AN-VC)]. The surgical implants were performed as close to the first day of the new menses cycle as possible. Two of the monkeys received devices which contained NGF-secreting cells and two of the monkeys received control devices containing unmodified cells. The implants were 0.7 mm outside diameter and 7 mm long. Each monkey received two implants in each ovary. Following laparatomy to expose the ovaries, the implants were inserted into the ovary using a large bore needle and plunger (a suture in the ovarian capsule prevented migration of the device). Following implantation, the monkeys that received the control cells have continued to cycle. After 3 cycles one monkey has had cycle lengths of 26, 28, and 27 days while the other control monkey has had cycle lengths of 30, 31, and 29 days. Measuring serum progesterone levels every third day confirmed the occurrence of normal ovulatory menstrual cycles. Thus far, the menstrual cycles of the monkeys receiving the NGF implants appear altered as judged by their progesterone profiles. The active life span of the corpus luteum appears shortened in both animals. While in one monkey the follicular phase is also shortened, thus decreasing the overall cycle length to 23 days, the second monkey is showing extended follicular phase (22 days), thereby resulting in cycle lengths that are either normal or extended in length. The data thus far collected suggest that overproduction of NGF in the ovary may disrupt cyclic ovarian function. A firmer conclusion will be obtained upon termination of the project in three more months.