Premium
Manganese accumulations in gill mitochondria of Crassostrea viginica
Author(s) -
Nuhar Ahmed,
Boisette Beatrix,
Carroll Margaret A.,
Catapane Edward J.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.890.10
Subject(s) - mitochondrion , crassostrea , oxidative stress , cytoplasm , manganese , biology , differential centrifugation , chemistry , biophysics , microbiology and biotechnology , biochemistry , oyster , organic chemistry , fishery
Manganese (Mn) is a neurotoxin causing Manganism in people exposed to high levels in the environment. Mn targets dopamine (DA) neurons in basal ganglia. Oxidative stress is implicated as factors of Mn toxicity and DA dysfunction. Mitochondria play a role as cause and target of oxidative stress damage. The mechanisms of damage is attributed to Mn's capacity to produce toxic free radicals and induce mitochondrial dysfunction. Mn is reported to accumulate in mitochondria and represent the primary pool of Mn in cells. Controversy exists to the extent of Mn accumulation in mitochondria. Some report Mn accumulates in nuclei and cytoplasm, not mitochondria. Our lab uses the oyster Crassostrea virginica as a test animal to study Mn neurotoxicty. We found Mn disrupts the DA system as well as mitochondrial respiration. To study where Mn accumulates within cells we used differential centrifugation and atomic absorption spectrometry. Gills were homogenized and centrifuged to isolate nuclear, mitochondrial and post‐mitochondrial fractions. Fractions were analyzed for Mn. To determine if isolated mitochondria accumulate Mn we prepared treated mitochondrial suspensions with up to 300 mM Mn. Results show a dose dependent accumulation of Mn in mitochondria of up to 5000%. Two day treatments with 500 and 1000 μM Mn increased Mn (μg/gdw) in gill from a baseline of 5.8 to 41.6 and 133.8, respectively, and centrifugation revealed Mn accumulations were primarily in nuclear and mitochondrial fractions. The study shows mitochondria accumulate Mn. In vivo treatments reveal accumulations with both the nuclear and mitochondrial fractions. The work was supported by 0516041171 of NYSDOE and 0622197 of DUE Program of NSF.