Sodium pump activity and calcium relaxation in vascular smooth muscle of deoxycorticosterone acetate-salt rats

Journal Article · Sat Nov 01 04:00:00 EST 1986 · Hypertension (Dallas); (United States)

DOI:https://doi.org/10.1161/01.HYP.8.11.1032· OSTI ID:6915098

Soltis, E E; Field, F P

The Na/sup +/-K/sup +/ pump activity was determined in femoral arterial smooth muscle from deoxycorticosterone acetate (DOCA)-salt hypertensive rats using potassium relaxation and ouabain-sensitive /sup 86/Rb uptake as indices. The membrane-stabilizing effect of calcium and its relation to Na/sup +/-K/sup +/ pump activity also were examined. Femoral arteries from DOCA-salt rats exhibited a greater relaxation in response to potassium addition after contraction with norepinephrine in a low potassium (0.6 mM) Krebs solution. The concentration of potassium required to produce a 50% relaxation was significantly less in DOCA-salt rats. Ouabain-sensitive /sup 86/Rb uptake was significantly greater at 3, 10, and 20 minutes of /sup 86/Rb incubation in femoral arteries from DOCA-salt rats. Linear regression analysis revealed a significant correlation between the uptake of /sup 86/Rb and time of incubation in both control and DOCA-salt rats. A significant difference in the slopes of the regression lines showed that the rate of uptake was greater in DOCA-salt rats. No difference was observed in ouabain-insensitive /sup 86/Rb uptake. A dose-dependent relaxation in response to increasing concentrations of calcium following contraction to norepinephrine was observed in femoral arteries from control and DOCA-salt rats. The relaxation was directly dependent on the level of extracellular potassium and was blocked by ouabain. Femoral arteries from DOCA-salt rats relaxed to a significantly greater extent in response to calcium at each level of potassium when compared with controls. These results provide further evidence for an increase in Na/sup +/-K/sup +/ pump activity in vascular smooth muscle from DOCA-salt hypertensive rats.

• Research Organization: Univ. of Florida, Gainesville
• OSTI ID: 6915098
• Journal Information: Hypertension (Dallas); (United States), Journal Name: Hypertension (Dallas); (United States) Vol. 11; ISSN HPRTD
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL ISOTOPES
ALKALI METALS
ALKALINE EARTH METALS
ANIMALS
ARTERIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CALCIUM
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
DISEASES
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELEMENTS
GLYCOSIDES
HYPERTENSION
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
METALS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
OUABAIN
POTASSIUM
RADIOISOTOPES
RATS
RODENTS
RUBIDIUM 86
RUBIDIUM ISOTOPES
SODIUM
STROPHANTHINS
SYMPTOMS
TRACER TECHNIQUES
UPTAKE
VASCULAR DISEASES
VERTEBRATES