Use of chemicals in practically every aspect of life has grown rapidly and international trade in bulk chemicals and consumer products has increased proportionately. Concern about possible health hazards that may arise from exposure to chemicals has increased throughout the world. Thus toxicology is concerned with the qualitative evaluation of spectrum of biological changes produced by exposure to chemicals.
One of the most abundant element in earths crust is Aluminium, which has no known biological function. Aluminium accumulation is suspected to be the causative factor of Alzheimers Disease. Aluminium has also been reported to be neurotoxic, causes Dialysis Encephalopathy and accumulation in patients.
Use of pesticides for pest control has increased worldwide towards improvement in agricultural output. Persistence of organochlorine compounds for control of pests created problems, which paved the way for Organophosphorous Pesticides [OP]. More than 2.29 billion pounds of active ingredient pesticides are used in USA alone. OP insecticides are effective as pesticides but can cause toxicity and even death in humans and animals following accidental or deliberate exposure. Continued exploration of OPs also led to discovery of DFP, the first tentative nerve gas.
The Nervous system is the coordinating system of all the information. The Central Nervous System comprising brain and spinal cord is concerned with conveying signals and relaying information from sense organs. In Humans acute OP poisoning can lead to cholinergic crisis. OP poisoning also leads to Intermediate Syndrome and Peripheral Neuropathy. Thus incidence and severity of pesticide exposure and poisoning is assessed with methods of diagnosis. Measurement of acetylcholinesterase enzyme activity forms a funtional index of toxicity in OP exposure.
Information transfer in the neurons in the brain is accomplished by release of the chemical-neurotransmitters, at the nerve endings. Toxic stress has a significant impact on neurotransmitters. Alteration in neurotransmitter level also reflects on the toxic effect of the test compound.
Thus research work was conducted to study the chronic [repeated exposure] toxic effect of Aluminium and the OP pesticide acephate on the different brain regions of the albino rat. Neurotransmitter changes, acetylcholinesterase enzyme activity and biochemical studies were thus conducted to study the toxic effect of the test compounds aluminium chloride and acephate.