Modelling interactions of acid-base balance and respiratory status in the toxicity of metal mixtures in the American oyster Crassostrea virginica.
Heavy metals, such as copper, zinc and cadmium, represent some of the most common and serious pollutants in coastal estuaries. In the present study, we used a combination of linear and artificial neural network (ANN) modelling to detect and explore interactions among low-dose mixtures of these heavy metals and their impacts on fundamental physiological processes in tissues of the Eastern oyster, Crassostrea virginica. Animals were exposed to Cd (0.001-0.400 microM), Zn (0.001-3.059 microM) or Cu (0.002-0.787 microM), either alone or in combination for 1 to 27 days. We measured indicators of acid-base balance (hemolymph pH and total CO(2)), gas exchange (Po(2)), immunocompetence (total hemocyte counts, numbers of invasive bacteria), antioxidant status (glutathione, GSH), oxidative damage (lipid peroxidation; LPx), and metal accumulation in the gill and the hepatopancreas. Linear analysis showed that oxidative membrane damage from tissue accumulation of environmental metals was correlated with impaired acid-base balance in oysters. ANN analysis revealed interactions of metals with hemolymph acid-base chemistry in predicting oxidative damage that were not evident from linear analyses. These results highlight the usefulness of machine learning approaches, such as ANNs, for improving our ability to recognize and understand the effects of sub-acute exposure to contaminant mixtures.
Macey
Brett M
BM
Hollings Marine Laboratory, Charleston, SC 29412, USA.
Jenny
Matthew J
MJ
Williams
Heidi R
HR
Thibodeaux
Lindy K
LK
Beal
Marion
M
Almeida
Jonas S
JS
Cunningham
Charles
C
Mancia
Annalaura
A
Warr
Gregory W
GW
Burge
Erin J
EJ
Holland
A Fred
AF
Gross
Paul S
PS
Hikima
Sonomi
S
Burnett
Karen G
KG
Burnett
Louis
L
Chapman
Robert W
RW
D000136:Acid-Base Equilibrium / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D049896:Crassostrea / Q000187:drug effects* / Q000502:physiology*; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D043143:Hepatopancreas / Q000187:drug effects / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism / Q000633:toxicity*; D008954:Models, Biological; D016571:Neural Networks, Computer; D012143:Respiratory Physiological Phenomena / Q000187:drug effects*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014018:Tissue Distribution / Q000187:drug effects
D019216:Metals, Heavy; D017392:Thiobarbituric Acid Reactive Substances; D005978:Glutathione