Hypothesis: inhibition of endothelium-derived relaxing factor by haemoglobin in the pathogenesis of pre-eclampsia.
Although the aetiology of pre-eclampsia is unknown, haemodynamic studies suggest that many of the clinical findings may be explained by a generalised vasoconstrictive disorder and abnormal endothelial cell function. Vasoconstriction may be attributed to the increased concentrations of haemoglobin found in pre-eclampsia compared with normal pregnancy. Free haemoglobin may be derived from haemolysis and placental haemorrhage and, at concentrations known to be present in pre-eclampsia, vasodilatation mediated by endothelium-derived relaxing factor is inhibited. Infusion of oxyhaemoglobin into human coronary arteries inhibits acetylcholine-induced vasodilatation. We suggest that an increased free haemoglobin concentration is the cause of vasoconstriction in pre-eclampsia.
Sarrel
P M
PM
Department of Cardiac Medicine, National Heart and Lung Institute, London, UK.
Lindsay
D C
DC
Poole-Wilson
P A
PA
Collins
P
P
D003331:Coronary Vessels / Q000187:drug effects; D005260:Female; D006454:Hemoglobins / Q000502:physiology*; D006801:Humans; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D010108:Oxyhemoglobins / Q000494:pharmacology; D011225:Pre-Eclampsia / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D011247:Pregnancy; D014661:Vasoconstriction / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects
D006454:Hemoglobins; D010108:Oxyhemoglobins; D009569:Nitric Oxide