الفهرس 
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Abstract
The kidneys are the primary organ for eliminating waste products of
the body, and eliminate most toxins and other foreign substances that are
either produced by the body or ingested, such as pesticides, drugs, and food
additives (Guyton and Hall, 2016).
Zinc oxide nanoparticles (ZnO NPs) are widely used in various
applications including cosmetics, paints, as drug carriers also in medical
materials (Dufour et al., 2006). These nanoparticles can also be used in
environmental industries due to their good absorptive and photocatalytic
properties for elimination or degradation of pollutants in water or air
(Qiang, 2001).
Exposure to ZnO NPs has potential toxicity, including cytotoxic,
genotoxic, and proinflammatory effects. ZnO NPs induce oxidative stress
through reactive oxygen species (ROS). High dose of ZnO NPs cause
nephrotoxicity and alternation in kidney metabolism in experimental animals
(Sharma et al., 2012).
ZnO NPs may exhibit unpredictable genotoxic properties. ZnO NPs
induces toxicity in various mammalian cells leading to potent DNA damage.
DNA damage may be caused by induction of oxidative stress and
inflammatory responses. ZnO NPs may cross cellular membranes and access
the nucleus, and DNA interaction resulted in its damage (Brown et al.,
2006).
Our study was performed to study histological ,histochemicals and
genotoxicty of ZnO NPs on adult male rabbits.
The present study was carried out on 15 adult male rabbits ,weighing
from 1.5 to 2 kg. The animals were divided into three groups randomly, 5
animals each.group Ι: kept without treatment as control group. group Π:
Summary and conclusion
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were received ZnO NPs intraperitonial injections in a dose 100ml/kg(0.4 cm
of prepared solution) once daily for 14 days. group ΠΙ: were received ZnO
NPs intraperitonial injections in a dose 250ml/kg (1cm of prepared solution)
once daily for 14 days.
The rabbits were sacrificed on the fifteenth day of the experiment
after being anaesthetized by ether. Kidneys and both femurs of each animal
were obtained. Kidney samples were examined by light microscope to study
histological and histochemical effects of ZnO NPs. Bone marrow samples
were analyzed by flowcytometery and DNA fragmentation assay.
Our results revealed that
1-ZnO NPs caused histological and histochemical changes especially
in high dose treated group. There were destruction of renal tubules in form
of vacuolation of cytoplasm, dense nucleus and loss of brush border of PCT.
There was prominent intratubular PAS positive deposition. There were
infiltrations of inflammatory cells in between tubules. Also there were
intraglomerular congestions.
2-In thise study there were prominent decrease in intensity of PAS
stain in the cytoplasm and loss of brush border especially in high dose
group. Also there were prominent fibrosis intra glomerular and in between
tubules in treated groups.
3- In our study we found an increase in the apoptotic cells of bone
marrow samples from 4.49% in control group to 7.39% in low dose treated
group and increase to 19.74 % in high dose treated group by using
propodium iodid flowcytometric kits.
4-In our study we used Anixin V FITC,it was found that, in control
group there were 1.92% late appoptic cells, 2.03% early appoptic and only
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75
0.54% was necrotic. In group II, we found that late appoptic cells were
3.59%, early appoptic cells were 2.84% and 0.98% were necrotic.In
groupIII, we found that late appoptic cells were 3.59%, early appoptic cells
were 2.84% and necrotic cells were 0.96%.these indicate ZnO NPs mainly
induce apoptosis not necrosis.
5- In the present study we examined DNA fragmentation by agarose
gel electrophoresis. High dose treatment led to significant increase in the
number of cells undergoing apoptosis as compared with control and other
low dose group. Further, this group showed intact DNA with no ladder
formation. On the other hand, administration of high dose presented a
prominent laddering/ DNA fragmentation.
Concolusion
ZnO NPs causes histolopathological changes of the kidney through
oxidative stress and has genotoxic effect on bone marrow.These may give us
more information on hazards of ZnO NPs on human health.