Sodium nitrite-induced hypoxic injury in rat hippocampus

To explore the effect of sodium nitrite-induced hypoxia on the hippocampus and the dentate gyrus in adult rats. Adult male albino rats, weighing 180-200 gm were divided into two groups and treated as follows: Group I: served as control and received normal saline, Group II: served as hypoxic rats and received sodium nitrite [75 mg/kg] subcutaneously. One hour after sodium nitrite injection, rats were decapitated. The brains were removed and placed overnight in fixative containing 10% formalin. These were paraffin- embedded for hematoxylin and eosin staining and cut at 5 micro in the coronal plane. Sections passing through bregma level -2.8 to -3.3 mm were used to count the neurons in the CA1, CA2, CA3, and CA4 subsectors and the dentate gyrus. Round, clear and medium or large neurons with distinct nucleus were counted. Cells with darkly stained shrunken nuclei and cells with fragmented nuclei were excluded from the count. Cytological examination of hypoxic brains depicted degeneration in hippocampus and dentate gyrus. Cell density was comparatively lesser in all the sub regions of hippocampus i.e. CA1-CA4 and Dg in the hypoxic brains. The degeneration was evident by presence of pyknotic nuclei, darkly stained cells, cells with condensed nuclei, as well as vacuolated spaces. The changes were more marked in CA3, CA4 and dentate gyrus. It is concluded that pyramidal neurons of the hippocampus and granular neurons of the dentate gyrus are very vulnerable to hypoxia and show regional differences in their vulnerability

Some biochemical aspects of suckling rats their mothers received different dose of sodium benzoate and nitrite

Fifty growing female albino rats [Spragus Dawley strain weighing 40-50g/each] were divided into 5 groups each of ten rats. One of them was fed on the diet free from any preservatives [control], two groups received acceptable and five folds sodium benzoate containing diet, while the last two groups received sodium nitrite at the acceptable and five folds level containing diet. Mature female rats were paired with normal males. Pregnant rats were separated and contained feeding the same diet. After delivery the pups were left for suckling until weanling. Suckling rats were sacrificed under ether anesthesia. Blood samples were taken in dry clean centrifuge tubes from the hepatic portal vein, brain was removed and homogenate in saline solution immediately. The results cleared that the suckling rats developed in mother treated with both sodium benzoate and nitrite at both level showed slightly lower values of serum AST activity. The nitrite treated groups at both levels showed an increase in the activity of serum ALT enzyme. While the suckling rats received high dose of benzoate showed an increase in serum alkaline phosphates activity 61.8%. But the suckling rats received acceptable dose of sodium benzoate showed high decrease in serum bilirubin. Serum urea level was decreased in the groups treated with acceptable dose of benzoate. Furthermore, the suckling rats treated with any of the benzoate or nitrite doses showed remarkable increases of serum uric acid level. While the suckling rats developed in mothers treated with any of the high dose of sodium benzoate or nitrite and suckled from them induced a remarkable increase of serum creatinine level. The high dose of benzoate and nitrite induced a significant decrease of brain RNA content, while the high dose of nitrite showed a decrease of brain DNA contain

Efecto del carcinogeno dimetilnitrosamina sobre el rinon del vison / Efect of carcinogen dimethylnitrasamine on the kidney of mink

Visones de un criadero que recibian alimentos, sobre la base de restos de pescado, evidenciaron un significativo aumento en su mortalidad, presencia de canceres hepaticos y alteraciones renales revelables histologicamente. Esos efectos fueron atribuibles a presencia, en el alimento, de dimetilnitrosamina (NDMA), en concentraciones 1,8 ug/g. En este trabajo se estudia en detalle el efecto de la NDMA sobre el rinon del vison. Visones que fueron tratados ip con NDMA(7 mg/kg en sol. fis.), mostraron dano evidenciable ultraestructuralmente en la corteza renal. El dano fue mayor en los tubulos proximales, que en los distales, pero era de naturaleza similar. Las celulas epiteliales tubulares de los animales intoxicados mostraron: a)Condensacion de la cromatina nuclear y dilatacion de la membrana perinuclear. b)Marcada hinchazon mitocondrial y ruptura de sus crestas con perdida de contenida de la matriz mitocondrial. c)Despegue de ribosomas y dilatacion del reticulo endoplasmico. d)Aumento del numero y tamano de las vacuolas autofagicas. e)Aparicion de gotas lipidicas en el citiplasma. En contraste con lo previamente establecido, para el caso de cancer hepatico del vison, el mecanismo del dano renal por NDMA no se pudo correlacionar directamente con la union de metabolitos reactivos de esta a proteinas o acidos nucleicos o la biotransformacion microsomal o mitocondrial de la NDMA o formaldehido. No obstante, el rinon biotransforma la NDMA a CO2, pero lo hace 3-4 veces menos intensamente que el rinon de rata. Los resultados sugeririan la presencia, en el caso del dano renal por NDMA, de mecanismos distintos de accion, a los habitualmente aceptados como responsables del dano hepatico o el renal en otras especies. Alternativamente, el dano renal puede deberse a dano hepatico concomitante