title: Inhalation of air polluted with gasoline vapours alters the levels of amino acid neurotransmitters in the cerebral cortex, hippocampus, and hypothalamus of the rat.
abstract: BACKGROUND
  This study was designed to investigate the impact of exposure to the vapours of two kinds of gasoline, a widely used fuel for the internal combustion engines on the levels of the amino acid neurotransmitters of the rat brain. Recent studies provide strong evidence for a causative role for traffic-related air pollution on morbidity outcomes as well as premature death (Health Effects Institute, 2009; Levy et al., 2010; von Stackelberg et al., 2013). Exposure to the vapours of gasoline or its constituents may be accidental, occupational by workers at fuel stations and factories, or through abuse as a mean of mood alteration (Fortenberry, 1985; Mc Garvey et al., 1999). Two kinds of gasoline that are common in Egypt have been used in this study. The first contains octane enhancers in the form of lead derivatives (leaded gasoline; G1) and the other contains methyl-tertiary butyl ether (MTBE) as the octane enhancer (unleaded gasoline; G2). The levels of the major excitatory (aspartic acid and glutamic acid) and the inhibitory (GABA and glycine) amino acid neurotransmitters were determined in the cerebral cortex, hippocampus, and hypothalamus.
  
  
  RESULTS
  The current study revealed that the acute inhalation of air polluted with the two types of gasoline vapours (1/2 LC50 for 30 min) induced elevation in the levels of aspartic and glutamic acids along with a decrease in glycine and GABA in most studied brain areas. Chronic inhalation of both types of gasoline (a single daily 30-min session of 1/5 LC50 for 60 days) caused a significant increase in the aspartic and glutamic acid concentrations of the hippocampus without affecting the levels of GABA or glycine.
  
  
  CONCLUSIONS
  Acute and chronic inhalation of either one of G1 and G2 vapours induced a disturbance and fluctuation in the levels of the free amino acids that act as excitatory and inhibitory neurotransmitters in the brain areas under investigation. These neurotransmitters are fundamental for the communicative functioning of the neurons and such effects may have a profound impact on the cognitive and sensorimotor functions of the brain resulting in serious psychological and physiological disorders..
authors.affiliation: Biology Department, College of Science, Dammam University, Postal Code 31113, P.O. Box 838, Dammam, Saudi Arabia. Electronic address: amalakinauy@ud.edu.sa.
authors.forename: Amal A
authors.initials: AA
authors.lastname: Kinawy
authors.affiliation: Zoology Department, Faculty of Science, Ain Shams University, Postal Code 11566, Cairo, Egypt. Electronic address: ahmed.ezzat@sci.asu.edu.eg.
authors.forename: Ahmed R
authors.initials: AR
authors.lastname: Ezzat
authors.affiliation: Biology Department, College of Science, Dammam University, Postal Code 31113, P.O. Box 838, Dammam, Saudi Arabia. Electronic address: balsuwaigh@ud.edu.sa.
authors.forename: Badryah R
authors.initials: BR
authors.lastname: Al-Suwaigh
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D005742:Gasoline / Q000633:toxicity*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D019570:Inhalation Exposure / Q000009:adverse effects*; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014835:Volatilization
chemical_list: D000393:Air Pollutants; D000596:Amino Acids; D005742:Gasoline; D018377:Neurotransmitter Agents
keywords: Aspartate; Brain areas; GABA; Gasoline vapour; Glutamate; Glycine; Leaded and unleaded gasoline; Neurotransmission