الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Bisphenol A, an endocrine disruptor, is a chemical largely used in the manufacture of polycarbonate plastics and epoxy resins found in many consumer products and dental sealants. Concerns were raised against the excessive usage of such substances. Consumption of BPA has been related to many diseases, including cardiovascular disease, diabetes mellitus and reproductive problems. Oxidative toxicity, on numerous tissues in the body, has also been stated after BPA exposure.
Selenium is stated to have antioxidant role in living systems. It is a fundamental component of several multivitamins. Selenium supplementation is shown to be effective to reduce salivary glands damage that are caused by oxidative stress.
we describe the impacts of Bisphenol A administration on the rats’ parotid salivary glands and to detect the protective action of selenium.
Thirty albino rats (180-200 gm) were used. Animals were maintained under the same environmental conditions.
The animals were randomly assorted into three groups, equal in number:
group I (control group): 10 rats received corn oil (vehicle) 1 ml every day during the whole period of the experiment which was 6 weeks.
group II (BPA group): 10 rats received 50 mg/kg body weight of BPA dissolved in corn oil orally one time daily for 6 weeks.
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group III (BPA + selenium group): 10 rats received 50 mg/kg body weight of BPA for with accompanied oral intake of Selenium with dosage of (0.25 mg/Kg) of body weight dissolved in distilled water.
Throughout the experiment, animals were examined weekly for overall general health and body weight. The animals in each group were euthanized, by overdose of diethyl ether, after six weeks. The rats were decapitated, and the parotid glands were taken. In each group, right parotid gland specimens were processed for Light microscope examination for evaluation of general histological features of the gland and histomorphometry analysis for quantitative analysis of acini mean surface area. The left parotid gland specimens were processed for transmission electron microscope examination for examination of the ultrastructural features of the gland.
Histological examination of group II (BPA group) revealed prominent vacuolization of the acinar cells’ cytoplasm with pyknotic nuclei. Abnormal widening of the intercalated ducts lumens was evident. Striated ducts showed loss of basal striations. Marked periductal fibrosis, where densely packed collagen fibers were seen around the excretory duct in the connective tissue. Dilatation and engorgement of blood vessels were also revealed.
Ultrastructural examination of BPA group confirmed the results obtained by the light microscope. Nuclei, in both acinar and ductal cells appeared extensively shrunken with irregular outline. Rough endoplasmic reticulum cisternae appeared dilated and fragmented. Mitochondria showed loss of its internal cristae.
In group III (BPA+ selenium), Both the histological and the ultrastructural results showed generalized enhancement with moderate restoration of the gland structure. Almost preserved serous acini as well as preserved ducts linings were seen. Less fibrous tissue deposition than in group II. Acinar and ductal cells exhibited almost normal nucleus. The cytoplasm of the cells
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occupying almost organized rough endoplasmic reticulum however, showing slight dilatation. Most of the mitochondria appeared normal toagreat extent in comparison with those seen in group II.
Histomorphometry results showed that group II (BPA) showed a decrease in the percentages of acinar surface area in comparison to group I (control). Moreover, the group III (BPA+ selenium) represented a highly significant increase in mean surface area than group (BPA).
We concluded that BPA produced significant degenerative changes on parotid glands of albino rats. The co-administration of Se showed a protective role against BPA-induced damage.