Nitrite disrupts multiple physiological functions in aquatic animals.

摘要: Nitrite is a potential problem in aquatic environments. Freshwater fish actively take up nitrite across the gills, leading to high internal concentrations. Seawater are less susceptible but do intestine and gills. has multiple physiological effects. Its uptake at expense of chloride, chloride depletion. also activates efflux potassium from skeletal muscle erythrocytes, disturbing intracellular extracellular K(+) levels. transfer erythrocytic membrane leads oxidation haemoglobin methaemoglobin (metHb), compromising blood O(2) transport. Other haem proteins oxidised. Hyperventilation observed, eventually tissue shortage becomes reflected elevated lactate Heart rate increases rapidly, before any significant elevations metHb or occur. This suggests nitrite-induced vasodilation (possibly via nitric oxide generated nitrite) that countered by increased cardiac pumping re-establish pressure. can form and/or mimic thereby interfere with processes regulated this local hormone. Steroid hormone synthesis may be inhibited, while changes ammonia urea levels excretion rates reflect an influence on nitrogen metabolism. Detoxification occurs endogenous nitrate, elimination takes place both gills urine. The susceptibility varies between species some cases within species. Rainbow trout fall into two groups regard response. These not related sex show different rates.