TY - JOUR
T1 - Changes in Lumbriculus variegatus metabolites under hypoxic exposure to benzo(a)pyrene, chlorpyrifos and pentachlorophenol
T2 - Consequences on biotransformation
AU - Agbo, Stanley O.
AU - Keinänen, Markku
AU - Lemmetyinen, Juha
AU - Akkanen, Jarkko
AU - Leppänen, Matti T.
AU - Mayer, Philipp
AU - Kukkonen, Jussi V.K.
PY - 2013
Y1 - 2013
N2 - The regulation of endogenous metabolites is still not fully understood in aquatic invertebrates exposed concurrently to toxicants and hypoxia. Despite the prevalence of hypoxia in the aquatic environment, toxicity estimations seldom account for multiple stressors thereby differing from natural conditions. In this study, we examined the influence of hypoxia (<30% O2) on contaminant uptake and the composition of intracellular metabolites in Lumbriculus variegatus exposed to benzo(a)pyrene (B(a)P, 3mugL(-1)), chlorpyrifos (CPF, 100mugL(-1)) or pentachlorophenol (PCP, 100mugL(-1)). Tissue extracts of worms were analyzed for 123 metabolites by gas chromatography-mass spectrometry and metabolite levels were then related to treatments and exposure time. Hypoxia markedly increased the accumulation of B(a)P and CPF, which underlines the significance of oxygen in chemical uptake. The oxygen effect on PCP uptake was less pronounced. Succinate and glycerol-3-phosphate increased significantly (p<0.0001) following hypoxic treatment, whereas sugars, cysteine, and cholesterol were effectively repressed. The buildup of succinate coupled with the corresponding decline in intracellular 2-oxo- and 2-hydroxy glutaric acid is indicative of an active hypoxia inducible factor mechanism. Glutamate, and TCA cycle intermediates (fumarate, and malate) were disturbed and evident in their marked suppression in worms exposed concurrently to hypoxia and PCP. Clearly, hypoxia was the dominant stressor for individuals exposed to B(a)P or CPF, but to a lesser extent upon PCP treatment. And since oxygen deprivation promotes the accumulation of different toxicants, there may be consequences on species composition of metabolites in natural conditions. Copyright 2013 Elsevier Ltd. All rights reserved.
AB - The regulation of endogenous metabolites is still not fully understood in aquatic invertebrates exposed concurrently to toxicants and hypoxia. Despite the prevalence of hypoxia in the aquatic environment, toxicity estimations seldom account for multiple stressors thereby differing from natural conditions. In this study, we examined the influence of hypoxia (<30% O2) on contaminant uptake and the composition of intracellular metabolites in Lumbriculus variegatus exposed to benzo(a)pyrene (B(a)P, 3mugL(-1)), chlorpyrifos (CPF, 100mugL(-1)) or pentachlorophenol (PCP, 100mugL(-1)). Tissue extracts of worms were analyzed for 123 metabolites by gas chromatography-mass spectrometry and metabolite levels were then related to treatments and exposure time. Hypoxia markedly increased the accumulation of B(a)P and CPF, which underlines the significance of oxygen in chemical uptake. The oxygen effect on PCP uptake was less pronounced. Succinate and glycerol-3-phosphate increased significantly (p<0.0001) following hypoxic treatment, whereas sugars, cysteine, and cholesterol were effectively repressed. The buildup of succinate coupled with the corresponding decline in intracellular 2-oxo- and 2-hydroxy glutaric acid is indicative of an active hypoxia inducible factor mechanism. Glutamate, and TCA cycle intermediates (fumarate, and malate) were disturbed and evident in their marked suppression in worms exposed concurrently to hypoxia and PCP. Clearly, hypoxia was the dominant stressor for individuals exposed to B(a)P or CPF, but to a lesser extent upon PCP treatment. And since oxygen deprivation promotes the accumulation of different toxicants, there may be consequences on species composition of metabolites in natural conditions. Copyright 2013 Elsevier Ltd. All rights reserved.
KW - Hypoxia
KW - Lumbriculus variegatus
KW - Metabolites
KW - Multiple stressors
KW - PCA
KW - Toxicometabolomics
U2 - 10.1016/j.chemosphere.2013.04.082
DO - 10.1016/j.chemosphere.2013.04.082
M3 - Journal article
C2 - 23742893
SN - 0045-6535
VL - 93
SP - 302
EP - 310
JO - Chemosphere
JF - Chemosphere
IS - 2
ER -