Toxic effect of 2,3,7,8,-tetrachlorodibenzo-p-dioxin [TCDD] on the lungs' alveolar epithelium of rats and the protective effect of vitamine E. a histological study

2, 3, 7, 8,-Tetrachlorodibenzo-p-dioxin [TCDD] has been classified as a known human carcinogen, and the epidemiologic studies identi5 the lung as one of the target organs. Few experimental studies have attempted to characterize pulmonary effects of TCDD exposure. Objective: Based on the theory of dioxin as a cause of oxidative stress, this work was designed to study the effect of chronic exposure to 2, 3, 7, 8,-Tetrachlorodibenzo-p-dioxin [TCDD] on the alveolar epithelium of rats and the use of the antioxidant; vitamin F to ameliorate this effect. Methods: Male Sprague Dawely rats were administered TCDD at a daily dose of 125 ng/kg body weight for 16 weeks. Another group of animals were co-administered TCDD [125 ng/kg body weight] and vitamin E in a daily dose of2Q mg/kg body weight for 16 weeks. Results: Administration of TCDD alone showed alteration in the lungs' alveolar architecture with marked thickening of the interalveolar septa, edema, cellular infiltration both peribronchiolar and perivascular together with vascular congestion and interstitial hemorrhage. Type II pneumocyte cells formed the predominant lining cells of the alveoli. Co-administration of TCDD and vitamin F showed considerable degree of preservation of the lung alveolar architecture. Most of the alveoli were patent lined with the two types of pneumocytes with type I predominance. Conclusion: The results established that prolonged gavage administration of TCDD to male Sprague Dawely rats can induce lung lesions, both proliferative and degenerative. In this work TCDD were unable to induce neoplastic changes, suggesting that additional factors are necessary for tumor induction. Alpha-tocopherol [vitamin F] effectively protected lung tissues against dioxin toxicity and this was attributed to its antioxidant properties

toxic effects of monomeric acrylamide on the testis of male albino rats, histological and ultrastructural study

Acrylamide [AA] is a reactive vinyl monomer used world wide to synthesize polyacrylamide [PAA] products. Although modern industrial techniques, designed to limit levels of monomeric AA in PAA, have resulted in decreased number of cases of AA acute toxicity, recent findings of moderate levels of AA in heated protein-rich foods and higher contents in carbohydrate-rich foods, have refocused worldwide attention on the health hazards of AA. this study was carried out to evaluate the toxic effects of acute and prolonged repeated monomeric AA exposure on the structure of the testis of albino rats and its potential reversibility. this study was conducted on 40 adult male albino rats weighing from 150-200 gm each. Animals were divided into three groups: Group I: 8 rats served as a control group. Group II: [16 rats] received one single dose of AA [25 mg/ kg bw] dissolved in water orally through gastric gavage. Group III: [16 rats] received AA dissolved in water in a dose of 20pg/ kg bw daily administered through gastric gavage for three months. All groups were subdivided into 2 subgroups: Subgroup [a]: were sacrificed one week after the end of exposure, Subgroup [b]: were sacrificed six weeks after the end of exposure. examination of testis of rats receiving one single toxic dose of AA and sacrificed after one week revealed moderate degenerative changes in spermatogenic cells with spermatocytes, spermatids and spermatozoa being the most vulnerable. Spermatogonia and Sertoli cells were resistant and showed mild affection. Leydig cells were nearly not affected. Rat testis of this group examined after six weeks withdrawal revealed considerable improvement in testicular tissue. More seriously was the prolonged very low dosage of AA [subgroup IIIa]. This caused severe and persistent damage affecting most somniferous tubules and interstitial Leydig cells. Nearly all spermatogenic cells spermatogonia and Sertoli cells were severely damaged. These changes were persistent even after six weeks withdrawal, This was attributed to the damaging effect on testicular stem cells, nursing Sertoli cells and the hormone secreting Leydig cells. Serious attention and close supervision must be paid towards exposure and especially of children to chronic acrylamide toxicity due to increasing population trends for consumption of fried potatoes, fried chicken, hamburgers and other forms of junk foods that proved to contain considerable amounts of acrylamide

Histological study of the effect of ciprofloxacin on the secretory acini of sublingual gland of albino rats

Ciprofloxacin is a synthetic fluroquinolone antimicrobial agent with a wide spectrum of antibacterial activity widely prescribed as the drug of choice to effectively treat certain infectious diseases. This work aimed at studying histological and ultrastructural changes of the secretory structures of the sublingual gland of rats following administration of ciprofloxacin. 30 adult male Sprague-Dawely rats were used in this study. Animals were divided into 3 groups; a control group received the diluent of the drug, a single dose group [group II] received 200 mg ciprofloxacin/kg body weight and group III in which animals received 40 mg/kg body weight/day for 21 days. Administration of the drug resulted in inflammatory and degenerative changes in both groups; yet, these changes were much more aggravated in group III. The mucous and serous elements as well as the secretory striated ducts of the sublingual glands showed cellular vacuolation, mitochondrial degeneration, and endoplasmic reticulum dilatation in group II rats. In group III, beside the previously described changes, many nuclei were irregular, dark and shrunken. The cytoplasm of some cells revealed rarefaction. Other cells showed densely packed organelles, irregular basement membrane and distortion of basal striations of the secretory striated duct. These changes were attributed to the toxic effect of prolonged ciprofloxacin administration on the nuclear and mitochondrial DNA, compromise of mitochondrial membrane and altered lysosomal membrane permeability. Ciprofloxacin caused a damaging effect that was reflected on the structure of the sublingual gland. Cautious use of ciprofloxacin and other antimicrobial agents should be considered in order to minimize their side effects

harmful effect of chronic hypervitaminosis D[3] on the skin and cardiac muscle of albino rat. A histological study

Is to investigate the effect of hypervitaminosis D[3] on the skin and cardiac muscle of albino rats. Eighteen adult male albino rats were used in this study. Rats were divided into two main groups. Group I [6 rats] served as a control group. Group II. [12 rats] to which vitamin D[3] were administered in a daily dose of 50,000 IU/kg body weight and subdivided into two subgroups. [Subgroup IIa] 6 rats received the preparation for two weeks and [Subgroup IIb]: 6 rats received the preparation for eight weeks. At the end of experimental periods, specimens were taken from the skin covering the back and the left ventricles of the heart of each animal. Animals of subgroup IIa showed epidermal affection as focal areas of decreased number of epidermal layers except for thickened stratum corneum, widening of the intercellular spaces between keratinocytes, loosened desmosomal junctions and microvillous transformation of the plasma membrane. These changes were marked and diffuse in animals of subgroup IIb. Layers beneath the stratum corneum were only one or two layers. Keratinocytes showed affection of the nuclei. The cytoplasm showed increased cytokeratin filaments and keratohyaline granules. Stratum corneum appeared thickened with wide spaces in between its layers and failure to form intact wavy bundles. Increased deposition of collagen bundles were noticeable in the dermis of most animals of this subgroup. The cardiac muscle of subgroup IIa showed damage of muscle fibers with widening of the spaces in between and interstitial odema, Breaking of continuity of myofibrils at the site of I band, partial degradation of Z-line material in many sarcomeres, thinning of myofibrils and mitochondrial swelling. The sarcolemma appeared lifted away from the underlying sarcomeres. Rats of subgroup IIb presented aggravation of these changes with severe cardiac muscle damage. Some cardiac myocytes appeared thinned with dark shrunken nuclei, others revealed dissolution with either karyolytic or pyknotic nuclei. Dehiscence of the intercalated disc with widened disc space, contraction bands with subsequent shrinkage of the sarcomere were also observed. Many myofibrils were disorganized, distorted and fragmented. The use of excessive doses of vitamin D resulted in severe damage to the skin and cardiac muscle. The use of vitamins should be restricted for individuals with documented deficiency or those at risk, especially fat-soluble vitamins because of their cummulative effect in the body

effects of electromagnetic fields on some neuroepithelial structures in the inner ear of rats

This work was dedicated to study the effects of long term exposure to time varying extremely low frequency electromagnetic fields on some neuroepithelial structures in the inner ear of rats. This work was conducted on 15 male adult albino rats, 5 rats were sham exposed and served as normal controls and 10 rats were exposed to time varying electromagnetic field of extremely low frequency [50 Hz] and 10-mT flux density for one hour daily, for 30 days. By the end of the experiment animals were anesthetized, perfused with the proper fixative then decapitated. The inner ears were reperfused and the temporal bones obtained. The specimens were put in a decalcifying agent for about 5 days. The specimens were prepared for either histological or scanning electron microscopical study. The present study revealed histological changes in all experimental specimens examined. The cochlea showed variable degrees of affection ranging from of cytoplasmic vacuolation of some supporting cells, to complete destruction of the organ of Corti. Stria vascularis showed atrophied lining cells. Spiral ganglionic cells appeared swollen with karyolitic nuclei. Vestibular neuroepithelial structures revealed milder response in the form of cytoplasmic vacuolation of both hair cells and supporting cells. From the previous results it could be concluded that long-term exposure to 10-mT extremely low frequency time varying electromagnetic field caused degenerative changes in the neuroepithelial structures of rat's inner ear

Pulmonary changes that occur in the interalveolar septa of albino rats exposed to nickel and the possible protective effect of magnesium. A histological study

Is to investigate the effect of exposure to nickel chloride on the interalveolar septa of lung of albino rats and the possible protective effect of simultaneous administration of magnesium acetate. Thirty adult male albino rats were used in this study. They were divided into 3 groups. Group I included 6 rats. They were used as normal controls. Group II, included 12 rats that were exposed to nickel chloride 5 days/ week for 4 weeks. Group III, included 12 rats that were given magnesium acetate simultaneously with nickel chloride for 4 weeks. Specimens were taken from the lung of all animals and were subjected to histological and ultrastructural studies. Rats lung of group II revealed evident degenerative pulmonary changes in the interalveolar septa of the lung with its marked thickening and collapse of many alveoli. The interstitium showed marked cellular infiltration, focal areas of oedema and deposition of collagen fibers. Some blood vessels appeared congested with marked extravasation of blood. Focal areas showed homogeneous eosinophilic material within the alveolar lumen and in the interalveolar septa. Electron microscopic study revealed alteration of normal alveolar lining with predominance of pneumocyte type II which showed atypical vacuolar inclusion in some cells. Others appeared shrunken with blunting of its microvillous border. Some alveoli showed severe degenerative changes and its lining exhibit hyaline membrane formation. Endothelial cells were sloughed in some capillaries with deposition of fibrillar osmophilic material on the epithelial aspect of the basal lamina. Proliferation of active macrophages was also seen. These changes were not evident in group III except for some cellular infiltration, thickening of interalveolar septum and focal oedema. Exposure to nickel chloride has deleterious effect on the delicate lung tissue, however, simultaneous administration of magnesium with nickel ameliorated significantly the harmful effect of nickel