Human exposure to NO3?/NO2? ions results largely from dietary ingestion http://www.selleckchem.com/products/MLN8237.html of these food products. Only a minor percentage comes from drinking water Inhibitors,Modulators,Libraries where the levels of these compounds usually comply with regulation (see below) [2,10].Methemoglobinemia is the Inhibitors,Modulators,Libraries principal adverse health effect caused by excessive nitrates/nitrites intake. Nitrite can irreversibly oxidize hemoglobin to methemoglobin which is unable to bind oxygen, causing clinical cyanosis among other symptoms. Infants are particularly susceptible to nitrite induced Inhibitors,Modulators,Libraries methemoglobinemia, often referred to as the blue-baby syndrome; a small number of fatal cases has been reported, generally associated to the consumption of water resources that failed drinking water standards [2,10].

Concern has been raised on the potential role of nitrite in forming carcinogenic N-nitroso compounds (NOCs) via reaction with secondary amines [16,17]. Although many NOCs have been shown to be genotoxic in animal models, the relationship between nitrites/nitrates intake and the risk of cancer in humans has Inhibitors,Modulators,Libraries not been unequivocally proved so far [10]. No matter the controversy, the information generated from the analytical surveillance of nitrite in food products is fundamental for the management of health risks.The issue of nitrates/nitrites toxicity led to the implementation of rules to restrict their level in drinking waters and foodstuffs. European directive 98/83/EC has established the maximum admissible levels of nitrate and nitrite in drinking water at 50 and 0.1 ppm, respectively. Likewise, the World Health Organization (WHO/SDE/WSH/07.

01/16) has set these limits at 50 ppm (NO3?) and 3 ppm (NO2?). More recently, following Cilengitide the European Food Safety Authority recommendations, 2006/52/EC directive Ruxolitinib manufacturer has reduced the authorized levels for nitrites and nitrates in meat and other food products, which should be controlled on the basis of added rather than residual amounts (e.g., 150 mg/kg of nitrites in meat products).Physiological AspectsNitrates and nitrites are also present in mammalian physiological systems, either from dietary provision or endogenous formation. The chemical reactions of these ions in the physiological environment are strongly related to the nitric oxide (NO) metabolism; the relationship between the three NOx species is a current matter of intense research and was recently reviewed by Hord et al. [10] and Lundberg et al. [18]. Nitric oxide is a crucial mediator in cell signal transduction that plays a critical role in numerous physiological processes and in the pathophysiology of many human diseases. Indeed, NO has a major role in regulating cardiovascular functions and modulating inflammatory, infectious and degenerative disorders.