Interleukin-6 does not stimulate rat myometrial contractions in an in vitro model.
OBJECTIVE
Interleukin-6 (IL-6) increases in culture-positive amniotic fluid in women with preterm labor. IL-6 stimulates the production of prostaglandins leading to increased uterine activity.


METHODS
We tested the hypothesis that IL-6 increases myometrial activity through release of uterotonic mediators. We studied the effect of IL-6 on uterine contractions in the absence and presence of fetal membranes to determine if the effect was on myometrium alone or was mediated through fetal membranes/decidua. IL-6 in concentrations of 100, 10, 0.1 or 0 ng/ml was added to the maternal side of the dual chamber-fetal membrane-uterine muscle in vitro model.


RESULTS
We found that 10 ng/ml of IL-6 alone, without fetal membranes, caused a significant decrease in uterine contractions over time (P < or = 0.01). This decrease was not observed with the addition of term, nonlabored fetal membranes.


CONCLUSIONS
IL-6 in the presence or absence of membranes, over a four log fold dose range, did not stimulate uterine contractions.
Dajani
N
N
Department of Obstetrics and Gynecology, MetroHealth Medical Center, Cleveland, Ohio 44109.
Idriss
E
E
Collins
P L
PL
D000818:Animals; D005321:Extraembryonic Membranes / Q000502:physiology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000502:physiology*; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D014590:Uterine Contraction / Q000276:immunology*
D015850:Interleukin-6; D007770:L-Lactate Dehydrogenase