Chapter 35 – Organophosphates and Carbamates

Organophosphates (OPs) and carbamates (CMs) constitute a large class of chemicals that are used worldwide in agriculture, and in human and veterinary medicine. These chemicals exert general toxicity by acetylcholinesterase (AChE) inactivation leading to acetylcholine accumulation at the synapses in the brain and neuromuscular junctions. OPs and CMs can also produce a variety of reproductive toxicity, including endocrine disruption and infertility. Following in utero exposure, these pesticides can induce embryotoxicity, fetotoxicity, teratogenesis, and abortion. During gestation, the period of organogenesis is the most critical for developmental toxicity. Developing organisms appear to be more sensitive than adults to OPs and CMs toxicity, and the brain is the primary target organ. Cholinergic and noncholinergic transmitters, receptors, and other molecules are modulated, in addition to oxidative stress and endocrine disruption, by OPs and CMs. Some of the neurochemical deficits in the developing organism can persist until senescence, adolescence, and adulthood thereby predisposing them for chronic diseases, such as diabetes, Alzheimer's, and Parkinson's.