Expression of adrenomedullin in the human corpus luteum

Objective: Adrenomedullin (AM) is a potent hypotensive peptide found in hum an pheochromocytoma tissue. In the present study, the expression of AM mRNA in the human ovary was examined. Design: Ovarian mRNA was analyzed in the follicle, the corpus luteum of mid -luteal phase, and early pregnancy. Setting: Gunma University School of Medicine, Gunma, Japan. Patient(s): Premenopausal women with histologically normal ovary who were u ndergoing salpingoophorectomy. Intervention(s): The dominant follicle and corpora lutea were isolated and total RNA was extracted from these tissues. Main Outcome Measure(s): Northern blot analysis of AM, receptor activity-mo difying protein 2 (RAMP2), and LH/hCG receptor mRNA in human samples. Result(s): An AM mRNA transcript of 1.6 kilobases (kb) was detected in corp us luteum tissue; this transcript was identical to that which has been dete cted in placenta and fetal membrane. The AM and LH/hCG receptor mRNA levels were low in the mature follicle but increased in the corpus luteum of the mid-luteal phase and were maintained during early pregnancy. A single trans cript of 0.8 kb for RAMP2 was also seen in the follicle and corpus luteum, the level of RAMP2 mRNA was relatively high in the preovulatory follicle an d RAMP2 was present in the corpus luteum. Conclusion(s): The expression of AM, its receptor, and LH/hCG receptor may be an important component in the process of development and differentiation of the corpus luteum. (Fertil Steril(R) 2000,74:141-5. (C) 2000 by America n Society for Reproductive Medicine).