THE INCREASED CONCENTRATION OF 2,3-DIPHOSPHOGLYCERATE IN RED-BLOOD-CELLS OF SPONTANEOUSLY HYPERTENSIVE RATS

It has been recognised that high haemoglobin oxygen capacity is essent ial for the development of high blood pressure in spontaneously hypert ensive rats. In the present study we have found increased concentratio n of 2,3 diphosphoglycerate (2,3-DPG) in red blood cells of spontaneou sly hypertensive rats (SHR) of Okamoto-Aoki strain. As 2,3-DPG is the major factor decreasing haemoglobin affinity to oxygen, our finding su ggests that at given value of pO(2) oxygen delivery to the tissue of S HR would be increased. Therefore increased concentration of 2,3-DPG in red blood cells of SHR would be of the pathophysiological meaning by promoting autoregulatory increase in total vascular resistance in this strain of rats. The mechanism responsible for enhanced synthesis of 2 ,3-DPG in SHR remains unclear. Intracellular alkalosis due to either h ypocapnia and/or an enhanced activity of Na+/H+ antiporter occurring i n SHR are the most plausible explanations for the above finding.