Early interest in selenium by nutritionists was first identified in the 1930 s as a toxic element, nowadays it is known to be important in livestock and human diet. Its poisonous nature arouses the curiosity of researchers to investigate the impact of this element in human and animal metabolism. However, selenium has become the center of attention due to its physiological functions explained on the basis of its role as an active component of the enzyme glutathione peroxidase (GSH-PX), which is responsible for the animal antioxidant defense by destruction of hydrogen peroxide and lipid peroxides. Selenium metabolism and toxicity has been consistently studied in different species but data investigations on camelidae species are very limited. Our current study is configured to investigate the selenium intolerance in dromedary camel and carry out the symptoms related to continuous selenium supplementation. Investigations showed that camel is potentially sensitive to selenium excess. Several symptoms revealed by their different intensity from 3 batches, resumed in alopecia - abnormal movement and posture, breathing difficulties, prostration, diarrhea, lost of weight and nervous alteration. (Résumé d'auteur)

L'analyse de quelques parametres biologiques chez les ouvriers de l'usine d'engrais chimiques ASMIDAL (Algerie), ainsi que chez les habitants d'une cite avoisinante (El Bouni) exposes aux emanations de cette usine, a montre des modifications de ces parametres en signe de contamination par des derives azotes. L'exposition experimentale par ingestion a une dose infraletale de nitrate d'ammonium, derive fabrique par ASMIDAL, a provoque, chez le rat, des modifications similaires a celles trouvees chez les personnes etudiees. Les variations ont concerne les taux d'hemoglobine, de methemoglobine, les globules rouges, les nitrates seriques et urinaires. En outre, on a constate chez le rat des modifications de l'activite de la rate et du foie