Enzymatic inhibition and morphological changes in Hoplias malabaricus from dietary exposure to lead(II) or methylmercury.
Neotropical fish traíra (Hoplias malabaricus) were used to investigate the effects of dietary doses of metals through individual exposures to either inorganic lead(II) or methylmercury, respectively, 21 microg Pb2+g(-1) w.w. and 75 ng H(3)C-Hg+g(-1) w.w., every 5 days, for 70 days (14 doses). The erythrocyte delta-aminolevulinic acid dehydratase (ALAd) activity was inhibited after 14 doses of Pb2+ and H(3)C-Hg+. The muscle cholinesterase (ChE) activity was inhibited after 14 doses of H(3)C-Hg+. Damage in cytoskeleton and nuclei were observed after exposure to inorganic lead. Individuals exposed to H(3)C-Hg+ showed the presence of atypical granules and vesicles, cytoplasm disorganization, and mitochondria damages in hepatocytes also after 14 doses. The present results demonstrate that erythrocyte ALAd and muscle ChE activities can be used as long-term biomarkers of sublethal, subchronic, and trophic exposures to Pb2+, and H(3)C-Hg+ in fish. Also the morphological aspects described in the present work confirm the toxicity of both studied metals.
Alves Costa
João Ricardo Maleres
JR
Departamento de Biologia Celular, Universidade Federal do Paraná, C.P. 19031, CEP 81.531-990, Curitiba, PR, Brazil.
Mela
Maritana
M
da Silva de Assis
Helena Cristina
HC
Pelletier
Emilien
E
Randi
Marco Antonio Ferreira
MA
de Oliveira Ribeiro
Ciro Alberto
CA
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001938:Brazil; D002800:Cholinesterase Inhibitors / Q000633:toxicity; D002802:Cholinesterases / Q000378:metabolism; D004032:Diet; D004784:Environmental Monitoring / Q000379:methods; D004791:Enzyme Inhibitors / Q000633:toxicity*; D004912:Erythrocytes / Q000187:drug effects* / Q000201:enzymology; D005240:Feasibility Studies; D005399:Fishes / Q000097:blood / Q000378:metabolism*; D020387:Food Chain; D005618:Fresh Water; D022781:Hepatocytes / Q000187:drug effects / Q000648:ultrastructure; D007854:Lead / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000648:ultrastructure; D008767:Methylmercury Compounds / Q000633:toxicity*; D009132:Muscles / Q000187:drug effects* / Q000201:enzymology; D009566:Nitrates / Q000633:toxicity*; D000623:Porphobilinogen Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D015415:Biomarkers; D002800:Cholinesterase Inhibitors; D004791:Enzyme Inhibitors; D008767:Methylmercury Compounds; D009566:Nitrates; D014874:Water Pollutants, Chemical; D007854:Lead; C017461:lead nitrate; D002802:Cholinesterases; D000623:Porphobilinogen Synthase; C004925:methylmercuric chloride