ABSTRACT
We have developed a rapid and simple gas toxicity evaluation system based on bioluminescence inhibition of a marine-derived wild luminous bacterium, Vibrio fischeri. The luminous bacteria were trapped using a thin polyion complex membrane in order to allow semi direct contact between the bacteria and toxic gases. Bioluminescence inhibition ratios of the present system to six reference gases, including benzene, trichloroethylene, acetone, NO(2), SO(2), and CO, were evaluated, and dose-response relationships were successfully obtained after 15 min of gas exposure, except for CO gas. The sensitivity to the five gases except for CO gas of the present system was 1-3 orders of magnitude higher than that in acute animal tests. The present system also allowed for the evaluation of overall toxicity of some environmental gases containing various chemicals. These results clearly demonstrated that the present system would be a valuable prototype for rapid and on-site acute toxicity detection of a gas mixture, such as environmental gases.
Subject(s)
Aliivibrio fischeri/metabolism , Gases/metabolism , Gases/toxicity , Membranes, Artificial , Animals , Biological Assay , Environment , Glass , Humans , Luminescent Measurements , Mice , Organic Chemicals/metabolism , Organic Chemicals/toxicity , Rats , Surface Properties , Time Factors , Water/chemistryABSTRACT
To simply evaluate toxicity for various types of exhaust-gas samples collected in various locations, we developed a small-scale (150 mL) batch-type completely closed gas exposure device incorporated with an air-liquid interface culture of a human alveolar epithelial cell line, A549. On the basis of cell viability tests using an acid phosphatase assay after 48 h of gas exposure, the developed device was able to measure clear dose-response relationships for volatile organic and inorganic compounds, such as benzene, trichloroethylene (TCE), acetone, SO(2) and NO(2) gases, but not CO gas. Although the 50% effective concentration values in the device were much higher than 50% lethal concentration values reported in animal experiments, the tendency of the toxic intensity observed in the former was roughly consistent with that of the acute toxicity in the latter. We further applied the device to evaluate the toxicity of cigarette smoke as an example of actual environmental gases, and successfully measured acute cell death from the gas after 48 h of exposure. The present small device is expected to be one of good tools not only in simultaneously assessing various gaseous chemicals or samples, but also in studying acute toxicity expression mechanisms in human lung epithelia.
Subject(s)
Air Pollutants/toxicity , Environmental Monitoring/methods , Epithelial Cells/drug effects , Inhalation Exposure , Pulmonary Alveoli/drug effects , Acetone/toxicity , Benzene/toxicity , Cell Line , Environmental Monitoring/instrumentation , Epithelial Cells/pathology , Humans , Nitrogen Dioxide/toxicity , Pulmonary Alveoli/pathology , Sulfur Dioxide/toxicity , Time Factors , Trichloroethylene/toxicityABSTRACT
Conventional in vitro cytotoxicity tests usually do not include toxicokinetic processes that affect final toxicity in the entire body. To overcome this limitation, we have been developing several types of new toxicity test systems and applying them to evaluate hazardous chemicals or environmental samples. In this review, we described two of these new systems; one is a batch-type gas exposure system based on air-liquid interface culture of lung epithelial cells, and the other is a simple double-layered coculture system incorporating permeation and biotransformation processes occurring in the small intestine. In addition, we introduce our latest approach toward further miniaturization of existing tests, that is, determination of minimum cell number necessary for obtaining physiologically-relevant tissue responses.
