Heptachlor and op´DDT effects on protein kinase activities associated with human placenta particulated fractions

MAGNARELLI G., SOUZA M.S AND P. DE D' ANGELO A. M

Journal of Biochemical and Molecular Toxicology

Wiley

Año: 2009 p. 185 - 192

1095-6670

ABSTRACT: Organochlorine pesticides have beendetected in placenta. The ability of heptachlor(HC) and 1,1,1-tricholoro-2-(2-chlorophenyl)-2-4-chlorophenyl)ethane (o-pDDT) to interfere withprotein phosphorylation was evaluated. In vitroincubations of cell-free placental villi homogenateswith a concentration range 1–100 μM were performed.In particulate fractions, total serine/threonine kinaseactivity was increased by 10 μM HC and o- p DDT(59% and 82%, respectively). Maximum eightfoldincrease was observed with 10 μM o- p DDT onprotein kinase A activity. By contrast, protein kinaseC activity was reduced by 10 μM HC and o- p DDT(40% and 52%, respectively). Endogenous substratephosphorylation studies demonstrated that slightbut significant increase in 24-kDa band labeling wasproduced in nuclear samples with 1, 10, and 100 μMHC and 100 μM o- p DDT. Exposition to 100 μM HCincreased 85-kDa band labeling. In mitochondrialfractions, 10 μM HC and o- p DDT increased 24- and65-kDa bands’ labeling. These data indicate that bothpesticides affect protein kinase activities in particulatefraction. Nuclear compartmentalization of thesecompounds, insertion in membranes, and chemicalstress production may be associated to the observedQ1effects, thus suggesting deleterious consequences insignaling pathways. C 2008 Wiley Periodicals, Inc.J Biochem Mol Toxicol 22:1–8, 2008; Published onlinein Wiley InterScience (www.interscience.wiley.com).DOI 10:1002/jbt.xx