Increased maternal plasma concentration of endothelin-1 during labor pain or on delivery and the existence of a large amount of endothelin-1 in amniotic fluid.
The concentration of endothelin-1 (ET-1) in plasma and amniotic fluid from normal pregnant women was determined by a sensitive sandwich-enzyme immunoassay system, established recently. The plasma ET-1 level increased gradually during normal pregnancy as the pregnancy advanced, the levels (0.40 +/- 0.02 pmol/l, n = 45) being significantly (p less than 0.05) higher after 29 weeks of gestation than those (0.32 +/- 0.01 pmol/l, n = 30) before 28 weeks of gestation. The plasma ET-1 level during labor pain was significantly higher (0.59 +/- 0.06 pmol/l, n = 10) than that (0.40 +/- 0.02 pmol/l, n = 45) in the 3rd trimester of pregnancy without labor pain (p less than 0.02). Moreover, a high level of ET-1 (17.38 +/- 0.25 pmol/l, n = 18) was detected in amniotic fluid on term delivery. The ET-1 level in amniotic fluid was significantly higher than the levels in maternal and umbilical cord plasma (p less than 0.001 and p less than 0.001, respectively). After delivery the maternal ET-1 level decreased gradually and 2 day postpartum ET-1 levels reached the normal non-pregnant level.
Usuki
S
S
Department of Obstetrics and Gynecology, University of Tsukuba, Ibaraki, Japan.
Saitoh
T
T
Sawamura
T
T
Suzuki
N
N
Shigemitsu
S
S
Yanagisawa
M
M
Goto
K
K
Onda
H
H
Fujino
M
M
Masaki
T
T
D000328:Adult; D000653:Amniotic Fluid / Q000032:analysis*; D001724:Birth Weight; D002851:Chromatography, High Pressure Liquid; D016232:Endothelins; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D005865:Gestational Age; D006801:Humans; D007124:Immunoenzyme Techniques; D007747:Labor Stage, First / Q000378:metabolism*; D007748:Labor Stage, Second / Q000378:metabolism*; D007743:Labor, Obstetric / Q000378:metabolism*; D010455:Peptides / Q000097:blood*; D011247:Pregnancy; D012737:Sex Factors
D016232:Endothelins; D010455:Peptides