RESUMEN
We investigated the antioxidant potential of gallic acid (GA), a natural compound found in vegetal sources, on the motor and oxidative damages induced by lead. Rats exposed to lead (50 mg/kg, i.p., once a day, 5 days) were treated with GA (13.5mg/kg, p.o.) or EDTA (110 mg/kg, i.p.) daily, for 3 days. Lead exposure decreased the locomotor and exploratory activities, reduced blood ALA-D activity, and increased brain catalase (CAT) activity without altering other antioxidant defenses. Brain oxidative stress (OS) estimated by lipid peroxidation (TBARS) and protein carbonyl were increased by lead. GA reversed the motor behavior parameters, the ALA-D activity, as well as the markers of OS changed by lead exposure. CAT activity remained high, possibly as a compensatory mechanism to eliminate hydroperoxides during lead poisoning. EDTA, a conventional chelating agent, was not beneficial on the lead-induced motor behavior and oxidative damages. Both GA (less) and EDTA (more) reduced the lead accumulation in brain tissue. Negative correlations were observed between the behavioral parameters and lipid peroxidation and the lead levels in brain tissue. In conclusion, GA may be an adjuvant in lead exposure, mainly by its antioxidant properties against the motor and oxidative damages resulting from such poisoning.
Asunto(s)
Antioxidantes/farmacología , Conducta Animal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Ácido Gálico/farmacología , Intoxicación del Sistema Nervioso por Plomo/prevención & control , Actividad Motora/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Encéfalo/metabolismo , Catalasa/metabolismo , Quelantes/farmacología , Modelos Animales de Enfermedad , Ácido Edético/farmacología , Conducta Exploratoria/efectos de los fármacos , Plomo , Intoxicación del Sistema Nervioso por Plomo/metabolismo , Intoxicación del Sistema Nervioso por Plomo/fisiopatología , Intoxicación del Sistema Nervioso por Plomo/psicología , Peroxidación de Lípido/efectos de los fármacos , Masculino , Nitratos , Porfobilinógeno Sintasa/metabolismo , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas WistarRESUMEN
This study was designed to assess the utility of two psychometric tests with putative minimal cultural bias for use in field screening of lead (Pb)-exposed Ecuadorian Andean workers. Specifically, the study evaluated the effectiveness in Pb-exposed adolescents and young adults of a nonverbal reasoning test standardized for younger children, and compared the findings with performance on a test of auditory memory. The Raven Coloured Progressive Matrices (RCPM) was used as a test of nonverbal intelligence, and the Digit Span subtest of the Wechsler IV intelligence scale was used to assess auditory memory/attention. The participants were 35 chronically Pb-exposed Pb-glazing workers, aged 12-21 yr. Blood lead (PbB) levels for the study group ranged from 3 to 86 microg/dl, with 65.7% of the group at and above 10 microg/dl. Zinc protoporphyrin heme ratios (ZPP/heme) ranged from 38 to 380 micromol/mol, with 57.1% of the participants showing abnormal ZPP/heme (>69 micromol/mol). ZPP/heme was significantly correlated with PbB levels, suggesting chronic Pb exposure. Performance on the RCPM was less than average on the U.S., British, and Puerto Rican norms, but average on the Peruvian norms. Significant inverse associations between PbB/ZPP concentrations and RCPM standard scores using the U.S., Puerto Rican, and Peruvian norms were observed, indicating decreasing RCPM test performance with increasing PbB and ZPP levels. RCPM scores were significantly correlated with performance on the Digit Span test for auditory memory. Mean Digit Span scale score was less than average, suggesting auditory memory/attention deficits. In conclusion, both the RCPM and Digit Span tests were found to be effective instruments for field screening of visual-spatial reasoning and auditory memory abilities, respectively, in Pb-exposed Andean adolescents and young adults.
Asunto(s)
Cognición/efectos de los fármacos , Intoxicación del Sistema Nervioso por Plomo/psicología , Pruebas Neuropsicológicas , Adolescente , Atención/efectos de los fármacos , Niño , Ecuador , Femenino , Hemo/metabolismo , Humanos , Plomo/sangre , Intoxicación del Sistema Nervioso por Plomo/diagnóstico , Masculino , Memoria/efectos de los fármacos , Exposición Profesional , Protoporfirinas/sangre , Psicometría , Percepción Espacial/efectos de los fármacos , Percepción Visual/efectos de los fármacos , Escalas de Wechsler , Adulto JovenRESUMEN
Lead intoxication affects the central nervous system and produces structural disorders and behavioral deficits in several animal species. Although lead neurotoxicity is a well-reported phenomenon, studies on the developmental neurotoxicity induced by this metal in avian are scarce. The aim of this study was to evaluate how a single dose of 28 mug lead acetate administered into the yolk sac on the fifth incubation day of Gallus domesticus can affect the behavior and the brain tissue in the first postnatal week. Several behavioral tests, mainly those related to the motor and exploratory functions were evaluated at fifth and sixth postnatal days (PN). The lead deposition into mesencephalon and cerebellum was investigated by autometallography (AMG) method. Congenital anomalies, as failure on closure of body's ventral midline and leg dysfunction, were observed in treated chicks. During the first postnatal week, inactivity and anomalous movements were significantly high in lead treated chicks in comparison to control animals. Lead impregnation was observed in both mesencephalon and cerebellum and the cerebellar molecular layer presented higher lead deposition in comparison to granular layer and Purkinje cells. Our results indicate that the in ovo exposure to lead induces important deficits on motor behavior of chicks during the first postnatal week and such phenomena are related to lead deposition in the cerebellar tissue during embryonic development. The proposed exposure schedule represents an interesting experimental approach for studding behavioral and cellular mechanisms related to lead-induced developmental neurotoxicity.