title: Effects of acetylcholine on the clearance of [3H]-antipyrine in bilaterally perfused lobules of human term placenta.
abstract: Single isolated lobules from human term placenta were bilaterally perfused with a balanced salt solution. The clearance of [3H]-antipyrine from the maternal to the fetal circulation was measured in an oper perfusion circuit (no recycling). Acetylcholine (ACh, 10 and 100 microM) was added to the maternal perfusate to examine the hypothesis that ACh may control permeability and transport processes across the placental membranes. ACh reduced the flow- and diffusion-limited clearance of [3H]-antipyrine in a reversible manner. Similar effects were obtained with physostigmine (eserine, 10 and 100 microM), an inhibitor of choline ester hydrolyzing enzymes, and ACh acted synergistically on this clearance reduction.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000983:Antipyrine / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008657:Metabolic Clearance Rate; D010477:Perfusion; D010830:Physostigmine / Q000494:pharmacology; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D014316:Tritium
chemical_list: D014316:Tritium; D010830:Physostigmine; D000109:Acetylcholine; D000983:Antipyrine