الفهرس 
Introduction and Aim of workOnly 14 pages are availabe for public view
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Abstract
Summary
Cd is a common significant metal, which might be discharged into the surroundings throughout industrial products. Se is a well-known antioxidant which is very important for human and animal life. Nanotechnology has enabled researchers to synthesize nanosize particles that possess enlarged surface areas. Compared to traditional microparticles, it resulted in enlarged interactions with biological purposes.
The current work provided a clue of the possible therapeutic role of Se-NPs on Cd induced histopathological changes in the thyroid gland. Se-NPs are customizable drug delivery vehicles that show good bioavailability, higher efficacy and lower toxicity than ordinary Se. Concomitant treatment of male rats with these Se-NPs has been recently shown to exert a protective effect against cadmium-induced thyroid dysfunction.
This study, therefore, aimed to investigate and characterize the potential protective mechanism of Se-NPs against cadmium-induced thyrotoxicity.
A total of 38 adult male albino rats were divided into 4 groups:
group I (8 rats): served as control and were given only distilled water for 35 days. Two of them will be sacrificed with each experimental group.
group II (10 rats) (cadmium-treated group): each rat received 200 parts per million (ppm) Cd (as CdCl2) in their drinking water for 35 days.
group III (10 rats) (Nano selenium-treated group): each rat received 0.1 ppm Se (as Na2SeO3) in their drinking water for 35 days.
group IV(10 rats) (experimental group): each rat was given Cd at the same dose, period and route of administration of the group II concomitantly with nano selenium at the same dose and route of group III for 35 days.
The rats of all groups were sacrificed at the same time after 35 days. Their thyroid glands were rapidly dissected out. The specimens of each group were processed for light and immunohistochemical studies. They were stained with hematoxylin and eosin, masson’s trichrome stain, and iNOS for evaluating follicular epithelial cells. Quantitative morphometric and statistical studies were performed.
The results of examination of the thyroid gland sections of the control group (group I) and Nano-Se treated group (group III) by light microscope were similar to the normal structure.
Results of group II showed significant histopathological changes in the thyroid gland. H and E stained sections showed loss of the normal architecture of the thyroid follicles. There was absence of colloid in some follicles, desquamated epithelial cells in the lumens of thyroid follicles, increased epithelial cell height, cytoplasmic vacuolations, large interfollicualar space and congested blood vessels. Masson’s trichrome sections showed increased collagen deposition.The immunohistochemical stained sections showed strong iNOS immunoreaction.
In group IV, concomitant treatment with Se-NPs effectively inhibited the Cd induced thyroid damage and succeeded in restoring the thyroid integrity induced by cadmium. H and E stained sections showed follicles of different diameters filled with colloid, with a predominance of larger follicles. There were decrease in the interfollicular space, apparent decrease in the follicular epithelial cell height but congested blood capillaries were still present. Masson’s trichrome sections showed significant decrease in collagen deposition. The immunohistochemical stained sections showed weak iNOS immunoreaction.