The objective was to compare various gonadotropin-based methods to stimulate ovarian follicular growth in female cynomolgus (n = 16) and African green monkeys (n = 8) for collection of mature oocytes. On the 1st day of menstruation, the monkeys were treated with 3.75 mg leuprorelin acetate (a GnRH agonist). Starting 2-3 weeks later, ovarian follicular growth was stimulated as follows: (a) 25 IU/kg of human FSH (hFSH) in a glycerol solution given once daily for 9 d; (b) 200 IU of eCG given six times during a 9-d interval; (c) 75 IU/kg hFSH in a glycerol solution given three times (72 h intervals) during a 6-d interval. In addition, the monkeys were given 1200 or 4000 IU of hCG 36 h (Methods A and 13) or 60 h (Method Q after the last gonadotropin treatment, and oocyte collection was attempted 36-38 h after hCG. Although there were no significant differences among methods in the number of oocytes collected, in cynomotgus monkeys, hFSH (Methods A and Q was better than eCG (Method 13; 12 and 10 versus 7 mature oocytes, respectively), whereas in African green monkeys, eCG (Method 13) was more effective than hFSH (Method A; 12 versus 7 mature oocytes). Furthermore, in cynomolgus monkeys, Method C was nearly as effective as Method A; using a glycerol solution as a solvent decreased the frequency of hFSH administration from nine to three times. In conclusion, in cynomolgus and African green monkeys, ovarian response depended on the species and on the individual, and in cynomolgus monkeys, hFSH in a glycerol solvent was effective. (c) 2007 Elsevier Inc. All rights reserved.