Regional alterations in the levels of brain biogenic amines, glutamate, GABA, and GAD activity due to chronic consumption of inorganic arsenic in developing and adult rats

Abstract

Arsenic contamination is widely prevalent in soils and waters of various parts of the world (World Health Organization, 1981). Arsenic consumption in humans has been reported to lead to cancer of skin and respiratory tract, liver damage, dermatosis, sensory motor polyneuropathy, hearing loss, EEG abnormalities and in extreme cases to hallucinations, disorientation and agitation (Beckett et al. 1986; Binder et al. 1987; Mazumder et ai.1988; Pershagen, 1986). In spite of awareness of its hazardous effects on the central nervous system (CNS) there have been no studies so far reported about the effects of chronic consumption of arsenic,particularly in the developing age, on biogenic amine neurotransmitters viz. noradrenaline (NA), dopamine (DA) and serotonin (5-HT).Hence this study was conducted to elicit information on the effects of chronic consumption of arsenic throughout developing age on the levels of these amines in different regions of the brain and the extent of restitution to normal levels after a long period of stopping consumption. In addition, it was also aimed to assess changes in glutamic acid decarboxylase (GAD) activity and in levels of glutamate and gamma-aminobutyric acid(GABA) as these amino acids are not only involved in carbohydrate metabolism but also in neurotransmitter pools. For comparative understanding, effects of arsenic intake in adult groups were also studied.