Effects of chronic exposure to cadmium, lead, and mercury on brain

Journal Article · Sun Oct 31 23:00:00 EST 1976 · Res. Commun. Chem. Pathol. Pharmacol.; (United States)

OSTI ID:7254554

Hrdina, P D; Peters, D A.V.; Singhal, R L

Effects of chronic (45 days) treatment with different doses of cadmium chloride (0.25 and 1.0 mg/kg/day), methylmercury chloride (0.4 and 4.0 mg/k/day) and lead acetate (0.2 and 1.0 mg/kg/day) and of 28-day withdrawal of treatment on the levels of acetylcholine (ACh) and activity of acetylcholinesterase (AChE) in cerebral cortex, and concentration of norepinephrine (NE) and 5-hydroxytryptamine (5-HT) in brain-stem were examined in rats. Exposure to both cadmium and methylmercury produced significant decreases in cortical ACh and brain-stem 5-HT levels. In addition, brain-stem NE concentration was increased in methylmercury-treated rats. In contrast, chronic treatment with lead resulted in enhanced cerebrocortical ACh levels but a decreased brain-stem NE concentration. Treatment with cadmium also produced a transient enhancement of striatal dopamine levels. Cadmium-induced decrease in brain-stem 5-HT and lead-induced accumulation of cortical ACh persisted even after 28 days withdrawal of treatment. The data indicated that chronic exposure to low doses of heavy metals produces differential changes in regional levels of various brain biogenic amines. These changes may represent the early signs of adverse effects on CNS function since they occur before any overt symptoms of neurotoxic effects of heavy metals become apparent.

• Research Organization: Univ. of Ottawa
• OSTI ID: 7254554
• Journal Information: Res. Commun. Chem. Pathol. Pharmacol.; (United States), Journal Name: Res. Commun. Chem. Pathol. Pharmacol.; (United States) Vol. 15:3; ISSN RCOCB
• Country of Publication: United States
• Language: English

Related Subjects

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550500 -- Metabolism
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACETYLCHOLINE
AMINES
AMMONIUM COMPOUNDS
ANIMALS
AROMATICS
AZOLES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL ACCUMULATION
BIOLOGICAL EFFECTS
BIOSYNTHESIS
BODY
BRAIN
CADMIUM CHLORIDES
CADMIUM COMPOUNDS
CADMIUM HALIDES
CENTRAL NERVOUS SYSTEM
CEREBRAL CORTEX
CEREBRUM
CHLORIDES
CHLORINE COMPOUNDS
CHOLINESTERASE
CHRONIC INTAKE
DOPAMINE
DRUGS
ELEMENTS
ENZYMES
ESTERASES
ESTERS
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY COMPOUNDS
INDOLES
INTAKE
KINETICS
LEAD COMPOUNDS
MAMMALS
METALS
METHYLMERCURY
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PARASYMPATHOMIMETICS
PHENOLS
POLYPHENOLS
PYRROLES
QUATERNARY COMPOUNDS
RADIOPROTECTIVE SUBSTANCES
RATS
REACTION KINETICS
RESPONSE MODIFYING FACTORS
RODENTS
SEROTONIN
SYMPATHOMIMETICS
SYNTHESIS
TOXICITY
TRYPTAMINES
VERTEBRATES