linkage of anp level to NA+,K+ -atpase, osmotic fragility under the effect of mannitol in crf patients

ABSTRACT

The present study was designed to determine the plasma level of ANP in chronic renal failure CRF patients before and after mannitol infusion in order to find whether the protective effect of mannitol is a primary action or is due to release of ANP, also, to elucidate the possible effects of mannitol on red cell membrane changes and enzyme activities in these CRF patients. To achieve this goal, 20 patients with CRF and 10 healthy controls were investigated for the following parameters Plasma ANP level, blood urea and creatinine concentration, blood picture, blood indices, the activity of erythrocyte Na-K-ATPase and hemolysis of red cell to different concentrations of NaCl. 500 ml 20% mannitol were given to uremic patients by i.v. infusion for 5 consecutive days. All the previous parameters were reestimated on the 5th day half an hour after mannitol infusion [MI] and then 24 hours after the last mannitol infusion [6th day]. From this study, it can be concluded that the volume loading by MI can be regarded as an important physiological stimulus of ANP release. This beneficial effect obtained by MI were transient and it is suggested that it is more advantageously replaced by an infusion of doses of synthetic h-ANP to obtain more durable results. Activation of sodium-potassium ATPase of the erythrocyte ghosts accompanying the elevated level of ANP in this study was supported by the positive correlation between Na-K-ATPase and ANP after MI