The effect of luteinizing hormone releasing hormone (LHRH) on progesterone and estradiol production was studied in human luteal tissue. Tissue slices were incubated in Ham's F-10 medium under an atmosphere of 95% O2: 5% CO2 at 37 degrees C for 4 h. Slices were treated with or without human chorionic gonadotropin (HCG) in the presence or absence of LHRH. HCG stimulated progesterone and estradiol production by human luteal tissue in a time- and dose-related manner. LHRH stimulated the basal progesterone production in five (one early luteal and four mid-luteal) of 17 corpora lutea, and stimulated the basal estradiol production in three (all mid-luteal) of 16 corpora lutea. On the other hand, LHRH inhibited HCG-stimulated progesterone production in four (two early luteal and two mid-luteal) of 22 corpora lutea, and inhibited HCG-stimulated estradiol production in four (one early luteal and three mid-luteal) of 18 corpora lutea. In the acute short-term incubations of human luteal tissue, therefore, LHRH had little effect on basal and HCG-stimulated steroidogenesis. However, in a few corpora lutea taken in the early or mid-luteal phase, LHRH stimulated basal steroidogenesis and inhibited HCG-stimulated steroidogenesis.