Muscarinic Cholinergic Receptors and Acetylcholinesterase Activity in Umbilical Artery and Vein in Pregnancy-Induced Hypertension (Pre-Eclampsia)

Abstract

The influence of pregnancy-induced hypertension (pre-eclampsia) on muscarinic cholinergic receptors and on acetylcholinesterase (AChE) activity was investigated using frozen sections of the umbilical artery and vein. Pre-eclamptic patients undergoing Caesarean delivery and normotensive pregnant control woman undergoing Caesarean delivery with similar parity, gestation length and age were examined. Muscarinic cholinergic receptors were assayed in frozen sections of the umbilical artery and vein by a radioligand binding assay technique, using [³H]-N-methyl scopolamine (NMS) as a ligand. AChE was demonstrated with a histochemical technique associated with microdensitometry.[³H]-NMS was specifically bound to sections of both umbilical artery and vein in a manner consistent with the labelling of muscarinic cholinergic receptors. The affinity of the radioligand was similar in the two vessels, whereas the maximum density of binding sites (B_max) was higher in the umbilical vein than in the artery. A faint

Key Words:

• Pre-eclampsia
• Muscarinic receptors
• Acetylcholinesterase
• Radioligand binding
• Umbilical artery
• Umbilical vein