title: Effects of sub-lethal and chronic lead concentrations on blood and liver ALA-D activity and hematological parameters in Nile tilapia.
abstract: Liver and blood δ-aminolevulinic acid dehydratase (ALA-D) inhibition by exposure to sub-lethal lead concentrations over time in Nile tilapia (Oreochromis niloticus) were investigated. All three lead concentrations (1mgkg(-1), 10mgkg(-1) and 100mgkg(-1)) significantly inhibited ALA-D activity in blood (319±29.2; 180±14.6 and 172±19µmols(-1)h(-1)L(-1) respectively) and liver (302±5.84; 201±41.4 and 93±22.1µmols(-1)h(-1)L(-1)) 24h after injection relative to controls (blood: 597±37.0µmols(-1)h(-1)L(-1); liver: 376±23.1µmols(-1)h(-1)L(-1)). Blood ALA-D was greatly inhibited in all but the highest lead dose. Fish were then exposed to 1mgkg(-1) lead for 9 days, and presented short-term hyperglycemia, decreased hemoglobin and hematocrit values and time-dependent blood ALA-D activity inhibition, corroborating blood ALA-D activity as being more suitable for investigating lead effects, showing dose and time-dependent ALA-D inhibition after lead exposure. The results of the present study also demonstrated that fish size affects blood ALA-D activity, as fish from the 24-h assay, which were slightly smaller (approximately 200g), showed higher ALA-D inhibition in response to lead exposure when compared to the fish from the 9-day assay (approximately 500g). Thus, fish size should always be taken into account both in the field and in laboratory settings, and efforts should be made to obtain uniform fish size samples for biomarker studies.
authors.affiliation: Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Instituto de Bioquímica Médica Leopoldo de Meis, Cidade Universitária, A. Carlos Chagas Filho, 373, Bl. D, S. 05, CEP 21941-902, Rio de Janeiro, RJ, Brasil; Centro de Estudos da Saúde do Trabalhador e Ecologia Humana, Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, CEP 21045-900, Rio de Janeiro, RJ, Brasil.
authors.forename: Carlucio Rocha
authors.initials: CR
authors.lastname: Dos Santos
authors.affiliation: Centro de Estudos da Saúde do Trabalhador e Ecologia Humana, Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, CEP 21045-900, Rio de Janeiro, RJ, Brasil.
authors.forename: Ana Luiza Michel
authors.initials: AL
authors.lastname: Cavalcante
authors.affiliation: Pontifícia Universidade Católica, Rua Marquês de São Vicente, 225, Gávea, CEP 22451-900, Rio de Janeiro, RJ, Brasil. Electronic address: rachel.hauser.davis@gmail.com.
authors.forename: Rachel Ann
authors.initials: RA
authors.lastname: Hauser-Davis
authors.affiliation: Laboratório de Comunicação Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, CEP 21045-900, Rio de Janeiro, RJ, Brasil.
authors.forename: Renato Matos
authors.initials: RM
authors.lastname: Lopes
authors.affiliation: Centro de Estudos da Saúde do Trabalhador e Ecologia Humana, Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, CEP 21045-900, Rio de Janeiro, RJ, Brasil.
authors.forename: Rita De Cássia Oliveira Da Costa
authors.initials: Rde C
authors.lastname: Mattos
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D023681:Cichlids / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006943:Hyperglycemia / Q000097:blood / Q000139:chemically induced; D020128:Inhibitory Concentration 50; D007854:Lead / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D000623:Porphobilinogen Synthase / Q000037:antagonists & inhibitors / Q000097:blood*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006454:Hemoglobins; D007854:Lead; D000623:Porphobilinogen Synthase
keywords: Environmental monitoring; Fish; Hematological parameters; Lead; Tilapia (Oreochromis niloticus); δ-aminolevulinic acid dehydratase