Uterine norepinephrine levels are correlated with contraction force, but not with the occurrence of preeclampsia.

The aim of the present experiments was to investigate a possible correlation between the occurrence of preeclampsia and the levels of norepinephrine in human myometrial biopsies obtained from the lower uterine segment at the time of cesarean section. Norepinephrine was measured directly by the technique of muscle CATS, and indirectly by measuring the effect of their release on the K(+)-induced force development of the myometrial strip. Two distinct types of force development depending on the level of endogenous norepinephrine were observed, but they were not correlated with the development of preeclampsia. This was confirmed by the absence of correlation between uterine norepinephrine levels and the occurrence of preeclampsia. Therefore, no correlation between myometrial catecholamine content and the development of preeclampsia could be demonstrated.