Calcium Antagonism in the Control of Cardiac Arrhythmias1

2015 ◽  
pp. 67-87
Author(s):  
Bramah N. Singh
Keyword(s):  
Calcium Antagonism

scholarly journals Calcium antagonism and the vasorelaxation of the rat aorta induced by rotundifolone

2004 ◽  
Vol 37 (12) ◽  
pp. 1881-1887 ◽  
Author(s):  
D.N. Guedes ◽  
D.F. Silva ◽  
J.M. Barbosa-Filho ◽  
I.A. Medeiros
Keyword(s):  
Rat Aorta ◽  
Calcium Antagonism

Older versus newer antidepressants: Substance P or calcium antagonism?

2007 ◽  
Vol 85 (10) ◽  
pp. 1004-1011 ◽  
Author(s):  
C. Boselli ◽  
M. Santagostino Barbone ◽  
A. Lucchelli
Keyword(s):  
Substance P ◽  
Receptor Subtypes ◽  
Dependent Manner ◽  
Depression And Anxiety ◽  
Guinea Pig Ileum ◽  
Response Curves ◽  
Concentration Dependent Manner ◽  
Calcium Antagonism ◽  
Blocking Activity ◽  
Concentration Response Curve

Substance P (SP) is possibly involved in the pathophysiology of depression and anxiety. We investigated interactions between antidepressants on SP-induced effects and their potential calcium-blocking activity in the isolated guinea pig ileum. All the antidepressants tested, except pargyline, moclobemide, mianserin, and reboxetine, were able to inhibit in a concentration-dependent manner the contraction induced by 100 nmol/L SP. Clomipramine, fluoxetine, maprotiline, and amitriptyline (all at 3 μmol/L) flattened the concentration–response curves to SP, resulting in a reduction of up to 59%, 63%, 32%, and 23%, respectively, of the maximum contractile effect. All the antidepressants tested (3 μmol/L), except pargyline, moclobemide, and mianserin, produced a rightward parallel shift of the concentration–response curve to CaCl2. The L-type selective calcium blocker nifedipine and the T-type selective mibefradil showed similar behaviour against both agonists used, SP and CaCl2. The relative order of potency was nifedipine (pA2, 7.6 ± 0.1) > clomipramine (pA2, 7.0 ± 0.1) > fluoxetine (pKB, 6.5 ± 0.1) = mibefradil (pKB, 6.6 ± 0.1) > amitriptyline (pKB, 6.3 ± 0.1) = maprotiline (pKB, 6.2 ± 0.1) > fluvoxamine (pKB, 5.9 ± 0.1). The data reported in the present study suggest that the antidepressants tested did not behave as competitive antagonists versus NK1-receptor subtypes, but their inhibitory action seems to be related to their calcium-blocking properties.

Calcium antagonism in essential hypertension: effect on renal haemodynamics and microalbuminuria

1992 ◽  
Vol 231 (3) ◽  
pp. 247-252 ◽  
Author(s):  
B. PERSSON ◽  
O. K. ANDERSSON ◽  
M. WYSOCKI ◽  
T. HEDNER ◽  
B. KARLBER
Keyword(s):  
Essential Hypertension ◽  
Renal Haemodynamics ◽  
Calcium Antagonism

Time-dependent Cardioprotection With Calcium Antagonism and Experimental Studies With Clevidipine in Ischemic-reperfused Pig Hearts: Part II

2002 ◽  
Vol 40 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Daisuke Segawa ◽  
Per-Ove Sjöquist ◽  
Qing-Dong Wang ◽  
Adrian Gonon ◽  
Lars Rydén
Keyword(s):  
Experimental Studies ◽  
Time Dependent ◽  
Calcium Antagonism

Calcium antagonism by the antioestrogen tamoxifen

1986 ◽  
Vol 18 (1) ◽  
pp. 17-20 ◽  
Author(s):  
A. Lipton ◽  
I. D. Morris
Keyword(s):  
Calcium Antagonism

Species Differ in Response to Adjuvants with Glyphosate

1992 ◽  
Vol 6 (3) ◽  
pp. 561-566 ◽  
Author(s):  
John D. Nalewaja ◽  
Robert Matysiak
Keyword(s):  
Calcium Chloride ◽  
Weight Reduction ◽  
Separate Experiment ◽  
Distilled Water ◽  
Water Spray ◽  
Fresh Weight ◽  
Calcium Antagonism ◽  
Diammonium Sulfate

Diammonium sulfate often is used as an adjuvant with glyphosate. Experiments were conducted in the greenhouse to determine the effectiveness of diammonium sulfate in overcoming calcium antagonism of glyphosate toxicity to wheat, sunflower, kochia, and soybean. Each species was a separate experiment and treatments varied with the experiment. Diammonium sulfate at 0.5% (w/v) in a spray carrier containing calcium chloride (500 ppm calcium) overcame calcium antagonism of glyphosate toxicity to wheat, overcame antagonism and enhanced toxicity to sunflower, but only partly overcame calcium antagonism of toxicity to kochia and soybean. With glyphosate at 100 g ae ha–1, diammonium sulfate at 2% (w/v) in a distilled water spray carrier enhanced toxicity to sunflower from a 11% to a 55% fresh weight reduction but was antagonistic to glyphosate toxicity to kochia and soybean.

Calcium antagonism—A New concept for treating essential hypertension

1986 ◽  
Vol 57 (7) ◽  
pp. D50-D53 ◽  
Author(s):  
Franco B. Müller ◽  
Peter Bolli ◽  
Paul Erne ◽  
Wolfgang Kiowski ◽  
Fritz R. Bühler
Keyword(s):  
Essential Hypertension ◽  
Calcium Antagonism

The Basis for the Hard-Water Antagonism of Glyphosate Activity

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 541-548 ◽  
Author(s):  
Kurt D. Thelen ◽  
Evelyn P. Jackson ◽  
Donald Penner
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ammonium Sulfate ◽  
Hard Water ◽  
Calcium Antagonism ◽  
Chemical Effects ◽  
Spray Solution ◽  
Type Complex ◽  
Over Time ◽  
Nuclear Magnetic

Hard-water cations, such as Ca+2and Mg+2, present in the spray solution can greatly reduce the efficacy of glyphosate. These cations potentially compete with the isopropylamine in the formulation for association with the glyphosate anion.14C-Glyphosate absorption by sunflower was reduced in the presence of Ca+2. The addition of ammonium sulfate overcame the observed decrease in14C-glyphosate absorption. Nuclear Magnetic Resonance (NMR) was used to study the chemical effects of calcium and calcium plus ammonium sulfate (AMS) on the glyphosate molecule. Data indicate an association of calcium with both the carboxyl and phosphonate groups on the glyphosate molecule. Initially, a random association of the compounds occurred; however, the reaction progressed to yield a more structured, chelate type complex over time. NH4+from AMS effectively competed with calcium for complexation sites on the glyphosate molecule. Data suggest that the observed calcium antagonism of glyphosate and AMS reversal of the antagonism are chemically based.

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