Red blood cell sodium in the DOCA hypertensive pig.

Abstract

SUMMARY The influence of deoxycorticosterone acetate (DOCA) on the sodium content of the red blood cell was determined in the pig. DOCA (100 mg/kg), impregnated in Silastic, was implanted subcutaneousty (s.c.) in six male pigs; seven additional pigs received Silastic implants without the DOCA. Those receiving DOCA had an increase in mean arterial pressure (MAP) that was significant in 48 hours and reached a plateau that was 24 mm Hg greater than that of the controls after 15 days. These animals also developed hypokalemia and polydipsia over approximately the same time course. sure often varies with the amount of sodium ingested, this element is thought to play an important role in some types of experimental and clinical hypertension. The mechanism by which sodium causes this effect is not known, but it is the central theme of much research. 12Investigators studying altered electrolyte metabolism of the red blood cell in hypertension have considered the possibility that this abnormality reflects changes that may occur in other tissues such as vascular smooth muscle or the central nervous system, in which the abnormality may play a causal role in the elevated arterial pressure. MIn the current study, we have observed that the development of deoxycorticosterone acetate (DOCA) hypertension in the pig is accompanied by an increase in intracellular sodium content in the red blood cell. Additional studies were carried out to explore possible mechanisms by which DOCA may produce this increase.

Erythrocyte lithium transport changes induced by deoxycorticosterone acetate treatment in pigs.

“…Species differences in the sensitivity of lithium fluxes to inhibition by phloretin have been reported by others for sheep, 16 rabbit, 16 and bovine red cells. 16 -l7 The results of these studies confirm and extend the previous observations of Guthe et al 13 on changes in red blood cell cation composition during the development of DOCA hypertension in pigs: compared with controls, in DOCA-treated pigs, cell sodium and water content rose while cell potassium content did not. The major new finding presented here is that of a progressive increase in SDLE concomitant with a decrease in lithium efflux into magnesium chloride.…”

Effects of diltiazem on cation transport across erythrocyte membranes of hypertensive humans.

“…Intracellular sodium concentrations were measured according to the method of Guthe et al 9 Heparinized blood (3 ml) was centrifuged at 1750 g for 5 minutes at 4°C, the plasma and buffy coat were removed, and the erythrocytes were washed five times with approximately 20 ml of ice-cold 110 mM MgCl 2 . Hematocrit was adjusted to approximately 50% following the last wash, and the hematocrit of the suspension was measured in triplicate.…”

Red Blood Cell Na⁺, K⁺ Pump Activity in Patients on Hemofiltration

“…This may be due to the reduced Na+,K+ pump activity, but an additional role could be played by the higher and more stable plas matic HCO3 concentration. It has been re ported that patients with chronic alkalosis have an elevated [Na+j] [7] and in vitro stud ies have confirmed this relationship [8], Among uremic patients, only those on HF have a mean RBC N a \K + pump activity close to that o f normal subjects. The plasma concentration o f potassium may influence the RBC Na+,K+ pump activity [9]: CAPD patients have lower plasma K+ concentration than HF (p < 0.001) and HD (p < 0.002) patients, when studied before treatment.…”