This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our goal is to investigate new drug therapies for endometriosis. Macaque endometrium can be auto-transplanted to ectopic intra-abdominal and subcutaneous sites. These endometrial grafts provide an excellent endometriosis-like model system for preclinical testing of novel anti-endometriotic therapies. Bayer Schering Pharma (BSP) is developing a testosterone analog (eF-MENT) that exerts higher androgenic activity than testosterone and is not converted to estrogens by the liver and fat tissues. In this study we will test the effect of eF-MENTon estrogen stimulated growth in endometrial grafts, and compare the effects of eF-MENT with the effects of dihydrotestosterone (DHT a natural androgen) as a positive control. This study has two aims: Aim 1 is to develop methods to identify nonreproductive "off-target" effects of androgens in female macaques that are analogous to the side effects of androgen therapy in women. Aim 2 is to determine if eF-MENT therapy will inhibit growth in ectopic endometrium in rhesus macaques. Dose finding studies with eF-MENT are underway.