Peroxynitrite effect on the haemoglobin oxygen affinity in vitro in presence of different partial pressure of carbon dioxide
Peroxynitrite (ONOO ) besides its toxic possesses regulatory action that includes the modulation of oxygen binding properties of blood. The aim of this work was to estimate ONOO effect on the haemoglobin oxygen affinity (HOA) in vitro in presence of different partial pressure of carbon dioxide (CO2). The ONOO presence in venous blood in conditions of hypercapnia induced oxyhaemoglobin dissociation curve shift leftward while in hypocapnic conditions the result of a different character was obtained. The revealed effect of ONOO is realized, possibly, through various modifications of haemoglobin whose formation is dependent on the CO<sub>2</sub> pressure. The ONOO influences the HOA in different manner that can be important in regulation of blood oxygenation in lungs and maintenance of oxygen consumption in tissues.