Requirements for human chorionic gonadotropin and recombinant human luteinizing hormone for follicular development and maturation

Purpose: Our purpose was to evaluate the requirements for human chorionic g onadotropin (hCG) and recombinant luteinizing hormone (rec-LH)for follicula r development and maturation in mice. Methods: We carried out ovarian stimulation of immature mice. Output parame ters were the preembryos created in vivo and frequency of blastocyst format ion in vitro. Results: hCG at 0 to I IU resulted in a dose-dependent recovery of preembry os (0 to 39. 7 +/- 4.3; mean +/- SE) per mouse. hCG at I and 10 hCG gave si milar results, whereas higher doses significantly reduced the number of pre embryos. Potential for blastocyst formation was independent of hCG dose, hC G and rec-LH together exerted a synergistic effect on the recovery of preem bryos. Conclusions: Optimal follicular development required a combination of 20 IU follicle stimulating hormone and I-IO IU hCC. The potency of hCG was highe r than that of rec-LH, but a synergistic effect of rec-LH and hCG was obser ved. The results may be pertinent for the development of strategies for ova rian stimulation of women with low levels of endogenous LH.