ABSTRACT
Polycyclic aromatic hydrocarbons (PAH) are ubiquitous contaminants of aquatic and terrestrial ecosystems, and are known to induce biochemical alterations in exposed organisms. Aside from a variety of adverse physiological effects associated with exposure to petroleum products, oils, and oil sludges, little is known about the effects of individual PAH on birds. Acute toxicity of naphthalene, pyrene, and benz[a]anthracene (BAA) was examined in adult northern bobwhite quail (Colinus virginianus). Additionally, subacute (8 d) and subchronic (60 d) studies were conducted to assess alterations in metabolic enzyme activity. Neither naphthalene, nor pyrene, nor BAA exposure via oral gavage produced acute toxicity up to the limit dose of 2 g/kg body weight. In the subacute study, quail provided feed containing the highest concentration of BAA for 5 d had significantly increased renal ethoxyresorufin O-deeththylase (EROD) activity compared to controls. Following a 3-d recovery period, significant increases between 10 and 100 mg/kg of BAA in feed existed for both hepatic EROD and pentoxyresorufin O-deethylase (PROD) activity compared to controls. Subchronic exposure to BAA (ranging from 0.1 to 10 mg/kg) also resulted in a significant rise of EROD and PROD in both kidney and liver tissue compared to controls. Though the individual PAH used in this study were not acutely toxic, these results confirm that these individual PAH induce alterations in metabolic enzyme activity in northern bobwhite quail.
Subject(s)
Benz(a)Anthracenes/toxicity , Colinus/metabolism , Environmental Pollutants/toxicity , Naphthalenes/toxicity , Pyrenes/toxicity , Animals , Cytochrome P-450 CYP1A1/metabolism , Cytochrome P-450 CYP2B1/metabolism , Cytochrome P-450 Enzyme System/metabolism , Kidney/drug effects , Kidney/enzymology , Liver/drug effects , Liver/enzymology , Toxicity TestsABSTRACT
We evaluated the use of the gas exchange rate as an ecologically relevant indicator of chemical stress in avian embryos/eggs. Northern bobwhite quail (Colinus virginianus) were exposed to octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) via feed containing nominal concentrations of 0, 12.5, 50.0, and 125.0 mg kg(-1). Metabolic rates (oxygen consumption) of developing quail eggs were then measured via respirometry to examine potential effects of HMX exposure. Metabolic rates were examined on 5, 9, and 21 d of incubation. Next, concentrations of HMX in embryos/eggs were determined by liquid chromatography-mass spectrometry. Mean (+/-SE) concentrations of HMX in eggs were 21.0+/-5.9, 1113+/-79.0, 3864+/-154.0, and 7426+/-301.1 ng g(-1) in control, low, medium and high dose groups, respectively. There were significant differences in oxygen consumption among the three embryo ages, however differences among the ages were not consistent among dose groups (age x dose group interaction p<0.0001). Oxygen consumption rates did not vary as a function of HMX in embryos (p=0.18). No evidence was observed for alterations of in ovo metabolic rates associated with HMX exposure.
Subject(s)
Azocines/toxicity , Colinus/metabolism , Embryo, Nonmammalian/drug effects , Explosive Agents/toxicity , Zygote/drug effects , Animals , Colinus/embryology , Embryo, Nonmammalian/metabolism , Oxygen/metabolism , Zygote/metabolismABSTRACT
Polyethoxylated tallowamine (POEA) is a non-ionic surfactant used in many herbicide formulations to increase the ability of active ingredients to penetrate leaf cuticles. However, it has also been shown to disrupt respiratory membranes in aquatic organisms. In this study, Daphnia magna was used to examine the lethal and sub-lethal toxicity of three POEA formulations consisting of 5:1, 10:1, and 15:1 average oxide:tallowamine. The formulation consisting of 10:1 was the most acutely toxic with a 48-h LC50 value of 97.0 microg/L and 15:1 was least toxic at 849.4 microg/L. All formulations inhibited growth at concentrations between 100 and 500 microg/L.
