Microvascular vasodilator response to acetylcholine is increased in women with pre-eclampsia.
OBJECTIVE
To evaluate in vivo microvascular responses to incremental doses of the endothelial-dependent vasodilator, acetylcholine, and the endothelial-independent vasodilator, sodium nitroprusside, in women with pre-eclampsia and gestation-matched normotensive pregnant controls.


METHODS
Prospective clinical study.


METHODS
Southern Derbyshire Acute Hospitals Trust, and University of Nottingham Division of Vascular Medicine.


METHODS
Thirteen women with pre-eclampsia and 16 normotensive pregnant controls.


METHODS
Cutaneous microvascular vasodilator responses to iontophoretic administration of incremental doses of acetylcholine and sodium nitroprusside (25-100 microC) were evaluated under temperature-controlled conditions using laser Doppler fluximetry.


RESULTS
Resting skin temperature and blood flow were similar among 13 women with pre-eclampsia [mean blood pressure 151/93 mmHg (4/3); mean gestation 35.6 weeks (1.0); and mean proteinuria 1.1 g/24h (0.2)] and 16 normotensive pregnant controls [mean blood pressure 111/63 mmHg (2/2); mean gestation 34.3 weeks (0.9)]. Peak vasodilator responses to acetylcholine were increased in women with pre-eclampsia (median flux ratio 15.1 [IQR 12.3-17.6] vs 11.7 [IQR 8.4-12.6], P < 0.05), whereas sodium nitroprusside responses were not different between the two groups: 11.4 [IQR 8.6-13.4] vs 9.5 [IQR 8.0-12.3].


CONCLUSIONS
In vivo microvascular vasodilator responses to acetylcholine are increased in women with pre-eclampsia, while endothelial-independent vasodilation is unchanged. Although the mechanism of acetylcholine induced vasodilation in small vessels is unclear, this study confirms previous animal data and provides in vivo evidence of altered microvascular endothelial cell function in pre-eclampsia.
Davis
K R
KR
Division of Vascular Medicine, University of Nottingham, and Southern Derbyshire Acute Hospitals NHS Trust, UK.
Ponnampalam
J
J
Hayman
R
R
Baker
P N
PN
Arulkumaran
S
S
Donnelly
R
R
D000109:Acetylcholine / Q000008:administration & dosage / Q000494:pharmacology*; D001808:Blood Vessels / Q000187:drug effects; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D005542:Forearm / Q000098:blood supply; D006801:Humans; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D009599:Nitroprusside / Q000008:administration & dosage / Q000494:pharmacology*; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy; D011446:Prospective Studies; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*
D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine