Endothelin-1 and big endothelin-1 increase in human endometrium during menstruation.
OBJECTIVE
Although the physiologic and pathologic roles of endothelin-1 in reproduction have been investigated, little is known about human uterine tissue levels. We studied the levels of immunoreactive endothelin-1 and immunoreactive big endothelin-1 in human endometrium and myometrium during each menstrual phase.


METHODS
Materials were obtained at hysterectomy (endometrium, n = 33; myometrium, n = 27). We measured immunoreactive endothelin-1 and immunoreactive big endothelin-1 by radioimmunoassay and performed an immunohistochemical study of the tissue. Data were analyzed by the Mann-Whitney U test.


RESULTS
We detected larger amounts of immunoreactive endothelin-1 and immunoreactive big endothelin-1 in the endometrium than in the myometrium throughout the menstrual, proliferative, and secretory phases. Endometrial immunoreactive endothelin-1 and immunoreactive endothelin-1 were significantly increased in the menstrual phase (endothelin-1 68.8 +/- 23.3 pg/mg protein, n = 5, p < 0.005; big endothelin-1 45.2 +/- 5.7 pg/mg protein, n = 5, p < 0.003) compared with the other phases (endothelin-1 30.7 +/- 9.5 and 30.5 +/- 14.0 pg/mg protein; big endothelin-1 19.9 +/- 6.7 and 24.1 +/- 7.4 pg/mg protein). Immunohistochemistry demonstrated that the endometrial stromal cells were positive for antiendothelin monoclonal antibody only in the premenstrual and menstrual phases.


CONCLUSIONS
Levels of immunoreactive endothelin-1 and immunoreactive big endothelin-1 are different in each type of uterine tissue and in each phase of the menstrual cycle. These changes may indicate some role of endothelin-1 in menstruation.
Ohbuchi
H
H
Department of Obstetrics and Gynecology, Miyazaki Medical College, Japan.
Nagai
K
K
Yamaguchi
M
M
Ikenoue
T
T
Mori
N
N
Kitamura
K
K
Araki
S
S
Toshimori
K
K
D000906:Antibodies; D003429:Cross Reactions; D004717:Endometrium / Q000378:metabolism* / Q000473:pathology; D019332:Endothelin-1; D016232:Endothelins / Q000032:analysis / Q000378:metabolism*; D005260:Female; D005831:Genital Diseases, Female / Q000378:metabolism / Q000601:surgery; D006801:Humans; D007044:Hysterectomy; D007150:Immunohistochemistry; D008597:Menstrual Cycle / Q000378:metabolism*; D008598:Menstruation / Q000378:metabolism*; D009215:Myometrium / Q000378:metabolism / Q000473:pathology; D011498:Protein Precursors / Q000032:analysis / Q000378:metabolism*; D011863:Radioimmunoassay; D014599:Uterus / Q000378:metabolism* / Q000473:pathology
D000906:Antibodies; D019332:Endothelin-1; D016232:Endothelins; D011498:Protein Precursors