Cholinergic system placental

As mentioned previously, maternal and/or fetal stress associated with sublethal exposures to OP insecticides could lead to an increased incidence of abortions or pre-term births in intoxicated pregnant women and animals. Because of lower levels of detoxifying enzymes (i.e. paraoxonase), the fetus appears to be more susceptible to OP intoxication than adults, and developmental neurotoxicity and growth retardation have been associated with low-level, prenatal exposures of humans to OP insecticides (Desaiah, 1998 Eskanazi et ah, 2008 Peiris-John and Wickremasinghe, 2008). In addition to the maternal and fetal effects, OP insecticides can also have direct toxic effects on the placenta, possibly involving (depending on the species) AChE inhibition within the placental cholinergic system (Pelkonen et ah, 2006). 

To our knowledge, there are no systematic studies that have exatnined the effects of OPs and CMs on the human placental cholinergic system. However, since OPs and CMs are known to inhibit AChE activity, it is expected that exposure of a pregnant woman to these compounds can lead to enhanced levels of ACh, and thereby ACh can influence other components of the cholinergic system in the placenta. 

Human placenta ha,s been recognized as a source of chorionic gonadotropin.s and steroid hormones. Since the development of the placental cholinergic system follows... 

Regulation of fetal growth by a placental cholinergic system. Fed. Proc. 35, 611,... 

Olubadewo, J. 0-, and Sasiry, B. V. R. (1978). Human placental cholinergic system Stimulation secretion coupling for release of acetylcholine from isolated placental villus, J. Pharmacol. Exit. 204,433 5. 

Sastry, B. V. R, Olubadewo. J. O., and Schmidt. D. E. (1973). Placental cholinergic. system and occurrence of acetylcholine in human placenta. Fed. Proc. 32, 742A. 

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