Reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemical observations revealed that human ovarian tissue expressed granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as GM-CSF alpha and beta receptor (R) mRNA and protein. The RT-PCR products revealed the predicted 286-, 546-, and 380-bp fragments for GM-CSF, GM-CSF alpha R, and GM-CSF beta R, respectively, which were further verified by restriction enzyme digestion analysis. In situ hybridization revealed that the theca interna of the large follicles and luteal cells are the exclusive site of GM-CSF mRNA expression. Furthermore, immunohistochemical studies using specific monoclonal antibodies indicated that the theca interna of the large follicles are the exclusive site of GM-CSF protein, whereas theca externa and to a lesser extent the granulosa cells are the major sites of GM-CSF alpha R and beta R proteins. Atretic follicles and follicular cysts showed very low or no detectable levels of GM-CSF and GM-CSF alpha R and beta R. In the luteal tissue, both the small and large luteal cells of early luteal (Days 14-19) and midluteal (Days 20-25) phase expressed GM-CSF mRNA and protein as well as GM-CSF alpha R and beta R proteins, and their immunostaining intensity was similar to that seen with theca cells. Luteal cells from late luteal phase (Days 26-28), corpus albicans, and ectopic pregnancy expressed a low level of GM-CSF, GM-CSF alpha R, and GM-CSF beta R mRNA and protein.(ABSTRACT TRUNCATED AT 250 WORDS)