The relation of cellular sodium to the onset of hypertension induced by DOCA-saline in the rat.
Groups of 15 rats were injected subcutaneously with a microcrystalline suspension of DOCA and given 1% saline as drinking water for periods ranging from 2 to 16 days. The in vivo transmembrane distribution of Na and K in relation to blood pressure was assessed in terms of plasma [Na] and [K] measured with ion-specific electrodes; smooth muscle cell Na, K and water were measured in the rapidly excised tail artery. A small increase in blood pressure was observed in week 1 of treatment and was followed by an abrupt increase to higher levels at about day 10. Plasma [Na] was elevated and [K] lowered throughout in a new steady state with a reciprocal change of about 1 mmol/l. There were minor changes in intracellular [K] in rapidly excised fresh tail artery samples so that the transmembrane K gradient (EK) was at all times increased by greater than 10 mV, indicating enhanced Na-K transport. In general, intracellular [Na] was directly and Na gradient inversely related to blood pressure (P less than 0.01).
Friedman
S M
SM
Department of Anatomy, University of British Columbia, Vancouver, Canada.
McIndoe
R A
RA
Tanaka
M
M
D000818:Animals; D001693:Biological Transport, Active; D002462:Cell Membrane / Q000378:metabolism; D003900:Desoxycorticosterone; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D007474:Ion Exchange; D008094:Lithium / Q000378:metabolism; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism*
D003900:Desoxycorticosterone; D008094:Lithium; D012964:Sodium; D011188:Potassium