Biomaterial Database

Contractile responses to ouabain and K+-free solution in aorta from hypertensive rats. 1986

R S Moreland, and T C Major, and R C Webb

This study characterizes isometric force development in response to ouabain and K+-free solution in isolated aortic strips from spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. SHR aortas were more sensitive to ouabain than those from WKY (threshold: SHR, 3.1 X 10(-5) M; WKY, 25.6 X 10(-5) M), and force development in response to 10(-3) M ouabain was greater in SHR (SHR, 586 +/- 51 mg; WKY, 245 +/- 24 mg). Monensin, a Na+ ionophore, potentiated contractile responses to ouabain, whereas amiloride, a Na+ channel blocker, and low Na+ solutions depressed contractile responses to ouabain. Contractile responses of SHR aortic strips to K+-free solution were faster than those of WKY aortic strips [time to half-maximal response (t1/2): SHR, 24 +/- 5 min; WKY, 47 +/- 4 min]. Maximal force development by aortic strips from SHR in response to K+-free solution was not different from that of WKY aortic strips (SHR, 808 +/- 34 mg; WKY, 750 +/- 37 mg). Monensin (10(-5) M) increased the rate of force development to K+-free solution to a greater extent in WKY aortic strips than in those from SHR (t1/2: SHR, 3 +/- 1 min; WKY, 4 +/- 2 min). Amiloride and low Na+ solution depressed contractile responses to K+-free solution in both SHR and WKY aortic strips. These observations demonstrate that SHR aortas are more responsive to ouabain and K+-free solution compared with WKY aortas. Contractile responses to ouabain and K+-free solution were sensitive to experimental interventions that alter transmembrane Na+ movements.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D006973	Hypertension	Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.	Blood Pressure, High,Blood Pressures, High,High Blood Pressure,High Blood Pressures
D008297	Male		Males
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D008985	Monensin	An antiprotozoal agent produced by Streptomyces cinnamonensis. It exerts its effect during the development of first-generation trophozoites into first-generation schizonts within the intestinal epithelial cells. It does not interfere with hosts' development of acquired immunity to the majority of coccidial species. Monensin is a sodium and proton selective ionophore and is widely used as such in biochemical studies.	Coban,Monensin Monosodium Salt,Monensin Sodium,Monensin-A-Sodium Complex,Rumensin,Monensin A Sodium Complex
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011918	Rats, Inbred SHR	A strain of Rattus norvegicus with elevated blood pressure used as a model for studying hypertension and stroke.	Rats, Spontaneously Hypertensive,Rats, SHR,Inbred SHR Rat,Inbred SHR Rats,Rat, Inbred SHR,Rat, SHR,Rat, Spontaneously Hypertensive,SHR Rat,SHR Rat, Inbred,SHR Rats,SHR Rats, Inbred,Spontaneously Hypertensive Rat,Spontaneously Hypertensive Rats
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat