ABSTRACT
Nitrate (NO3-) and nitrite (NO2-) are naturally-occurring oxidation products of nitrogen which widely used in thefood industry. The goal of this study was to illustrate the histopathological effects of sub-lethal dose of sodiumnitrite on jejunal mucosa and the possible protective effect of vitamin A. Thirty adult male Albino rats weredivided into 3 groups as follows: Group I (control) received distilled water, Group II (Nitrite-treated) whichreceived intra-gastric daily dose of 50 mg/kg NaNO2 and Group III (Nitrite & vit-A treated group) which receivedintra-gastric daily dose of 50 mg/kg NaNO2 +10,000 I.U/ rat vitamin A. Animals were sacrificed 8 weeks aftertreatment. Blood samples were collected and examined. Specimens from jejunal mucosa of rats were collectedfor the optical and electron microscope study. The blood samples showed significant reduction in all blood cellscounting and albumin level with elevated methemoglobin level in the nitrite treated group. Light microscopicexamination revealed that; Sodium nitrite cause jejunal mucosa damage represented by abnormal shape andlength of jejunal mucosa villi, necrosis with marked loss of covering epithelium and excessive cellular infiltrationin its core of lamina. PAS stained sections exhibited weak or negative PAS reaction of goblet cells of brush borderof villi and crypts. The entrocytes and goblet cells showed ultrastructural changes. Vitamin A administrationresulted in marked regression of the previously mentioned jejunal mucosal effects. Results of the current studyrevealed that diatry supplemtation of nitrite cause multible jejunal mucosal injury but the co-administration ofVitamin A greatly reduce the toxic effects of nitrite supplementation on jejunal mucosa