Acetylcholinesterase activity in the amniotic fluid of normal Thai pregnant women.

ABSTRACT

Acetylcholinesterase (AChE) activity was determined for 112 amniotic fluid samples obtained by amniocentesis from normal Thai pregnant women at gestational ages of 34 to 40 weeks. The method for estimation was based on inhibition the of non-specific cholinesterase (ChE) with ethoprorpazine and the expression of residual AChE activity as a percentage of total cholinesterase activity. The mean values of AChE and total ChE activities were found to be 3.65ฑ1.97 U/1 (range 1.10-7.72 U/1) and 7.61ฑ 2.55 U/1 (range 3.31-14.34 U/1) respectively. These values were in the same order of magnitude as results reported earlier in normal pregnant women. There were no relationships between gestational ages and amniotic fluid AChE, ChE or total ChE activities. As the concentration of AChE in the amniotic fluid is the index of the secreted AChE from neurons, it therefore increases considerably in fetus with open neural tube defect (NTD). The results for this pregnant women study is a base-line data for normal Thai pregnant women which will be useful in detecting the NTD in the fetus.