Human placental choline acetyltransferase activity at parturition

Abstract

Choline acetyltransferase (ChAT) activity measured in human placentae obtained during labour, or after labour of spontaneous onset, was significantly lower than that measured in placentae obtained before the onset of labour. The reduction in ChAT activity may partly account for the reduction in placental acetylcholine (ACh) content and release into maternal vessels at this time. When cycloheximide (10 μ/ml) was infused for 3 h into both fetal and maternal vessels of the perfused placental lobule, it did not significantly alter placental ChAT activity or ACh output from the fetal vessels, though it significantly reduced placental βHCG release from the maternal side of the perfused lobule. The..