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The effect of bradykinin (BK) on cytosolic calcium in coronary venular endothelial cells (CVEC) was studied using the intracellular calcium indicator indo 1. At normal extracellular calcium levels, CVEC responded to BK at concentrations as low as 0.1 pM; maximum cytosolic calcium spikes occurred at 10 nM. In calcium-free medium, poststimulation cytosolic(More)
Administration of nitroprusside (NP) subsequent to induction of contraction in canine renal arterial strips with norepinephrine (NE) yielded a dose-dependent relaxation and with 80 mM potassium (KCl) yielded only a small degree of relaxation. The effect elicited with 0.1 mM NP was significantly greater for responses obtained with NE (68%) than for those(More)
In rabbit aorta, pretreatment with KT-362 (KT; 10(-6) and 10(-5) M) inhibited contractile responses to norepinephrine (NE; 3 X 10(-9)-10(-5) M) and methoxamine (10(-7)-10(-4) M) but failed to affect responses to potassium (10-70 mM). KT (10(-5) M) partially inhibited Ca++-induced contractions in K+-depolarized aorta pre-equilibrated in a Ca++-free medium.(More)
Among chicken strains, broilers are prone to pulmonary hypertension, whereas Leghorns are not. Relaxations to endothelium-dependent (ACh, A23187) and endothelium-independent [sodium nitroprusside (SNP), papaverine (PPV)] vasodilators were compared in preconstricted pulmonary artery (PA) rings from these chicken strains. ACh (10(-7), 10(-6), and 10(-5) M)-(More)
  • R K Hester
  • 1985
The effects of 2-nicotinamidoethyl nitrate (SG-75) on norepinephrine (NE)- and KCI-induced responses in rabbit aorta were quantitated, correlated with 45Ca studies and compared with the effects of nifedipine (NIF) on similar parameters. NE- and KCI-induced dose-response relationships were differentially depressed by SG-75 (NE much greater than KCI) and NIF(More)
  • R K Hester
  • 1988
Specific receptor-linked Ca++ entry (RLCa++E) was studied separately from Ca++ release and potential-dependent Ca++ entry (PDCa++E) in rabbit aorta after incubation in a Ca++-free solution containing ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid to bind trace levels of Ca++ and including methoxyverapamil (D600) (10(-5) M) to inhibit(More)
The vascular relaxing properties of three beta adrenoceptor antagonists, betaxolol, carteolol and timolol, currently used in the treatment of glaucoma, were characterized, compared and contrasted in the porcine long posterior ciliary artery. Isolated arterial ring segments precontracted with increased extracellular KCl (plus 40 mM) or the thromboxane(More)
The influence of Mg on Ca- and K-related responses of rabbit aortic strips was studied. Aortic strips bathed in either a K-free or 60.0 mM K solution were less sensitive to Ca in the presence of 1.2 mm Mg. Ca induced greater maximum tension in the aortic strips in the presence of Mg when bathed in 60.0 mM K. Addition of K to a K-free medium induced a slight(More)
Chronic reserpine pretreatment resulted in an increase in the basal developed force generated by papillary muscles isolated from the right ventricle of the rabbit. In addition, supersensitivity to the inotropic effects of isoproterenol and a concomitant increase in beta-adrenoceptor number were demonstrated. These results indicate that reserpine-induced(More)
The relationships between tension responses to norepinephrine (NE) and high potassium (KCl) and high affinity 45Ca binding and mobilization were compared in canine renal arteries and veins. Contractile responses to 80 mM KCl were inhibited 83 (veins) and 88% (arteries) after respective 5-min and 60-min incubation periods in solutions with no added Ca++;(More)