Related Experiment Video
Updated: Oct 22, 2026

Instrumentation of Near-term Fetal Sheep for Multivariate Chronic Non-anesthetized Recordings
Published on: October 25, 2015
Amniotic fluid norepinephrine concentration as an indicator of fetal sympathetic nervous activity. Effect of
The concentrations of norepinephrine in amniotic fluid and maternal plasma were measured in 71 third trimester pregnancies, 31 of which were uncomplicated and 40 complicated. The amniotic fluid norepinephrine concentration (mean +/- SD) in cases of hypertension treated with clonidine (0.4 +/- 0.1 ng/ml, n = 12) and in insulin-dependent diabetes (0.5 +/- 0.2 ng/ml, n = 7) was lower, and in renal insufficiency (1.7 +/- 0.8 ng/ml, n = 8) higher than in control subjects (0.7 +/- 0.4 ng/ml, n = 31). In fetal-growth retardation (0.6 +/- 0.2 ng/ml, n = 8) and in latent diabetes (0.7 +/- 0.2 ng/ml, n = 5) the values were similar to those in the control subjects. There was a significant positive correlation between mature lecithin-sphingomyelin (L/S) ratio and norepinephrine concentration. Clonidine-treated hypertension was associated with decreased (0.2 +/- 0.1 ng/ml) and renal insufficiency with increased (0.9 +/- 0.7 ng/ml) maternal plasma norepinephrine concentrations (control group, 0.3 +/- 0.1 ng/ml). The present results indicate that measurement of catecholamines in amniotic fluid can be useful in the evaluation of fetal sympathoadrenal function.
The concentrations of norepinephrine in amniotic fluid and maternal plasma were measured in 71 third trimester pregnancies, 31 of which were uncomplicated and 40 complicated. The amniotic fluid norepinephrine concentration (mean +/- SD) in cases of hypertension treated with clonidine (0.4 +/- 0.1 ng/ml, n = 12) and in insulin-dependent diabetes (0.5 +/- 0.2 ng/ml, n = 7) was lower, and in renal insufficiency (1.7 +/- 0.8 ng/ml, n = 8) higher than in control subjects (0.7 +/- 0.4 ng/ml, n = 31). In fetal-growth retardation (0.6 +/- 0.2 ng/ml, n = 8) and in latent diabetes (0.7 +/- 0.2 ng/ml, n = 5) the values were similar to those in the control subjects. There was a significant positive correlation between mature lecithin-sphingomyelin (L/S) ratio and norepinephrine concentration. Clonidine-treated hypertension was associated with decreased (0.2 +/- 0.1 ng/ml) and renal insufficiency with increased (0.9 +/- 0.7 ng/ml) maternal plasma norepinephrine concentrations (control group, 0.3 +/- 0.1 ng/ml). The present results indicate that measurement of catecholamines in amniotic fluid can be useful in the evaluation of fetal sympathoadrenal function.
More Related Videos
Related Concept Videos
Hormonal Regulation
Local Anesthetics: Differential Sensitivity of Nerve Fibers
Local Anesthetics: Clinical Application as Epidural Anesthesia
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine...
Neural Regulation of Blood Pressure
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...
Hormonal Regulation of Blood Pressure
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction while...
Heart Failure II: Pathophysiology

