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

Effect of a new antidote on changes in pancreas in paracetamol toxicity. [a histological study]

Acetaminophen is a widely used analgesic antipyretic agent. Toxic doses ofthe drug have been shown to produce pancreatitis. The present study wasconducted to evaluate the effect of a new antidote [diltiazem] onacetaminophen induced pancreatic toxicity in mice. This study was carried outon 24 mice divided into three equal groups: Control group, intoxicated groupreceiving a single toxic dose of paracetamol [500 mg/kg] intraperitoneally anda protected group receiving diltiazem eight hours after receiving the sametoxic dose of paracetamol. The animals were sacrificed two hours after theend of the experiment. Histological and ultrastructural studies revealed analteration in the pancreatic structure after acetaminophen intoxication in theform of degeneration of acini, dilatation of ducts, congestion, loss ofelastic tissue of blood vessels and degranulation of beta cells. Calciumchannel blocker [diltiazem] produced a significant protective effect on thepancreas, which appeared more or less normal in structure