Biological Studies of Materials Arising from Energy Operations
Free Radical Studies on Mechanisms of Action
Project Title: of Pollutants
RX-03-06- (a)
14,
Scope: (Cont'd,)
organism is initially exposed.
Hence the biological significance of EPR
findings regarding the potential toxicity of pollutants would be heightened
if host-mediated assays were employed, using appropriate implantations of
agents in animals to permit biotransformations (whether activating or
detoxifying) to take place.
EPR surveys of implants or host tissues
themselves would allow the possibility of developing an in situ or in vivo
EPR assay for pollutant carcinogenicity or mutagenicity to be evaluated,|
Nitrogen oxides are among the volatile products of combustion
of fossil fuels (as well as of tobacco smoke), and their atmospheric
photochemistry is responsible for most of the color and much of the recog-
nized biological irritation due to photochemical smogs.
As oxidizing
chemicals, some even being free radicals (e.g., nitric oxide), radidmimetic
character might be anticipated, possibly including long-range effects
such as carcinogenesis or mutagenesis.
However, Little documentation is
in hand regarding the distribution, reactions and biological fate of
nitrogen oxides or the other atmospheric oxidants associated with fuel
combustion, such as ozone,
EPR and related double resonance spectroscopies have the potential
to analyze from biological samples (including cells and tissues) the para-
magnetic centers that are formed by the association of nitrogen oxides
with hemoglobin and with other heme proteins (especially cytochromes), as
well as more stable free radicals (such as lipoperoxides) that may be
produced by the reactions of radiation, nitric oxiden, ozone, etc,, with
lipids and biological membranes,
In fact a crude EPR survey some years
ago reported the generation of paramagnetic sites in distant tissues of
animals that breathed air containing various combustion products, including
nitrogen oxides,
:
.
The special capability of the BNL bioenergetic program involving
free radicals to carry out EPR and double resonance measurements on tissue
samples could readily be extended to monitor the attack of ozone and
nitrogen oxides in intact animals,
Additional studies on cells,
their
components, and on biochemicals would complement the work, and its inter-
pretation would be further supported by accompanying microscopic and bio-
chemical analyses,
The possibility should be considered of using EPR
technigues to develop an assay for human exposure to some of the environmenta
ents of chis class.
vate buildup in ground water may result from leaching that
follows the strip mining of coal, as well as from sewage and fertilizers,
The biological consequences have been thought to be mostly those associated
with eutrophication; however, there are some indications that levels of
both nitrites and nitrates in drinking water may be important to health.
(See Continuation Sheet)
1119325
RX-382