The influence of potassium and bicarbonate on red blood cell sodium in the DOCA-hypertensive pig.
The effects of plasma potassium, and blood bicarbonate on red blood cell sodium were studied in vivo in seven pigs implanted subcutaneously with DOCA (100 mg/kg) impregnated in Silastic. Mean arterial pressure, red blood cell sodium, plasma sodium, plasma potassium, and blood bicarbonate were measured from 5 days pre-implant to 30 days post-implant. One day post-implant, the pigs had significant increases in mean arterial pressure and red cell sodium content, and a significant decrease in plasma potassium concentration. In KCl infusion studies when plasma potassium was raised an average of 2.13 +/- 0.17 mEq/L, red blood cell sodium fell 0.61 +/- 0.10 mEq/L cells. When blood bicarbonate was raised 6.9 mEq/L by infusing NaHCO3, red blood cell sodium increased 0.79 mEq/L cells. The changes in red blood cell sodium were rapid, occurring within one hour after either of these plasma electrolyte shifts. We conclude that either plasma potassium or blood bicarbonate, or both, can serve as regulators of red blood cell sodium content in vivo, and cause the elevated level of red blood cell sodium that we have found in the DOCA-hypertensive pig. If these plasma electrolyte changes cause a similar increase in intracellular sodium in vascular smooth muscle or in a blood pressure regulating center in the brain, they may play a role in producing the arterial pressure elevation of mineralocorticoid-induced hypertension.
Gierada
D S
DS
Department of Physiology, University of Michigan, Ann Arbor 48109.
Bohr
D F
DF
D000818:Animals; D001639:Bicarbonates / Q000097:blood*; D003900:Desoxycorticosterone; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006973:Hypertension / Q000097:blood*; D011188:Potassium / Q000097:blood*; D012964:Sodium / Q000097:blood*; D013552:Swine
D001639:Bicarbonates; D003900:Desoxycorticosterone; D012964:Sodium; D011188:Potassium