Neurotoxic effect of lead at low concentrations

• Published in: Brain research bulletin Vol. 55; no. 2; pp. 269 - 275
• Main Authors: Mameli, O, Caria, M.A, Melis, F, Solinas, A, Tavera, C, Ibba, A, Tocco, M, Flore, C, Sanna Randaccio, F
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier Inc 15.05.2001; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Brainstem; Chemical and industrial products toxicology. Toxic occupational diseases; Dose-Response Relationship, Drug; Environmental Exposure - adverse effects; Female; Heavy metals; Lead - toxicity; lead acetate; Lead Poisoning, Nervous System - pathology; Lead Poisoning, Nervous System - physiopathology; Male; Medical sciences; Metals and various inorganic compounds; Neurotoxins - toxicity; Nystagmus, Physiologic - drug effects; Nystagmus, Physiologic - physiology; Post-rotatory-nystagmus; Rat; Rats; Rats, Long-Evans; Reflex, Vestibulo-Ocular - drug effects; Reflex, Vestibulo-Ocular - physiology; Toxicology; Vestibular Nuclei - drug effects; Vestibular Nuclei - pathology; Vestibular Nuclei - physiopathology; Vestibulo-ocular-reflex; Water Pollutants, Chemical - toxicity; Vestibulo-ocular-reflex; Post-rotatory-nystagmus; Rat; Heavy metals; Brainstem; Toxicity; Brain stem; Rodentia; Central nervous system; Heavy metal; Vertebrata; Mammalia; Animal; Nystagmus; Vestibuloocular reflex; Lead; Brain (vertebrata)
• ISSN: 0361-9230; 1873-2747
• DOI: 10.1016/S0361-9230(01)00467-1

The effects of lead exposure at low concentrations were evaluated by studying the post-rotatory nystagmus (PRN) in two groups of rats exposed for 3 months to 50 parts per million (ppm) of sodium acetate and 50 ppm of lead acetate, respectively, in the drinking water. Only animals treated with lead acetate showed changes of the PRN parameters which were significantly related to the concentration of lead in the blood and in brain structures. The patterns of PRN responses were characterized and classified into four types: progressively inhibitory (40%), prematurely inhibitory (25%), late inhibitory (25%), and excitatory-inhibitory (10%). No alterations of the PRN parameters were observed in the animals treated with sodium acetate. The results show that exposure to lead, even at low concentrations, impairs both sensory and motor functions. The findings also point out that the vestibular system and brain stem structures which generate and control the PRN represent targets of the action of this heavy metal. Finally, the results indicate that the evaluation of the vestibulo-ocular-reflex can provide a test suited for the screening of the neurotoxic effects of lead even in the absence of clinical signs typical of lead intoxication.