Effects of amrinone, a cardiotonic drug, on calcium movements in dog erythrocytes.

Parker, John C.; Harper, John R.

doi:10.1172/jci109851

Cited by 38 publications

(3 citation statements)

References 18 publications

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“…In the acute, drug-induced heart failure model, such as that caused by large doses of the P-adrenergic-blocking agent propranolol (20,136), the calcium channel blocker verapamil (12,124), or the anesthetic agent pentobarbital (31,128), milrinone (30 pg/kg prime, followed by 3 pg/kg/min infusion) caused increases in cardiac contractile force and cardiac output, decreases in right atrial pressure and total peripheral resistance, and no changes in heart rate or blood pressure (4). Since the common mechanism of the negative inotropic effect of propranolol, verapamil, and pentobarbital involves interference with Ca2+ fluxes and intracellular Ca2 + levels (19,23,43,57,58,87,88), and since amrinone and milrinone were shown to increase myocardial Ca2+ influx (44,79,84,96), it is likely that the enhanced myocardial performance is due to increased intracellular Ca2 + .…”

Section: Effects On the Failing Heartmentioning

confidence: 99%

Milrinone

Alousi

Fabian

Baker

et al. 1985

Cardiovascular Drug Reviews

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Section: Effects On the Failing Heartmentioning

confidence: 99%

Milrinone

Alousi

Fabian

Baker

et al. 1985

Cardiovascular Drug Reviews

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“…via the Na+-Ca++ exchange [10], the mechanism of action of amrinone remains obscure. It has been suggested that amrinone might modify the Na+-Ca++ exchange by either reducing Ca++ efflux [9] or increasing Ca++ influx [13]. Other studies have suggested that amrinone may stimulate phosphodiesterase [7].…”

Section: Amrinone-ouabain Interaction In Ventricular Musclementioning

confidence: 99%

Developmental Changes in the Interactions of Amrinone and Ouabain in Canine Ventricular Muscle

Binah¹,

Rosen²

1983

Dev Pharmacol Ther

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We studied the effects of amrinone on contractility and aftercontractions of ouabain-superfused ventricular muscle from neonatal and 3-month-old dogs. In 3-month ventricular muscle, amrinone, 5.3 x 10^-4 M, alone, increased active tension by 150%. When amrinone was superfused over ouabain-treated ventricular muscle, the increment in contraction was greatest for those muscles in which ouabain had induced a small positive inotropic effect and diminished as the positive inotropic effect of ouabain increased. Amrinone alone did not induce aftercontractions but increased the amplitude of those induced by ouabain by 92 ± 6 %. In neonatal ventricular muscle, amrinone alone was negatively inotropic and it decreased the increment in active tension induced by ouabain.

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“…Conceivably, in these preparations amrinone may be operating through mechanisms involving direct modification of Ca2+ transport or a different alteration of cAMP metabolism when compared with normal tissue. Indeed the stimulatory effects of amrinone on Ca2+ transport in dog erythrocytes involve the Na-Ca exchange mechanism (Parker & Harper 1980). The aims of the present study were to examine the inotropic effects of amrinone in rabbit papillary muscles with normal or depressed contractile function and to analyse the involvement of CAMP.…”

mentioning

confidence: 96%

Enhancement of Amrinone-induced Positive Inotropy in Rabbit Papillary Muscles with Depressed Contractile Function: Effects on Cyclic Nucleotide Levels and Phosphodiesterase Isoenzymes

Shahid

Rodger²

1991

Journal of Pharmacy and Pharmacology

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The inotropic activity of amrinone and its effects on cyclic nucleotide levels in rabbit papillary muscles with normal and depressed contractile function have been compared. The effects of amrinone on the cyclic (c) AMP hydrolytic activity of cyclic nucleotide phosphodiesterase (PDE) isoenzymes were also examined. Amrinone (2.4 x 10(-4) - 1.2 x 10(-3) M) produced a relatively weak (maximal increase 11%) positive inotropic effect in papillary muscles stimulated at the near optimal stimulation frequency of 1 Hz. In contrast, large positive inotropic responses (maximal 138-200%) were obtained with amrinone in papillary muscles in which contractile force had been depressed by: (a) lowering stimulation frequency to 0.4 Hz, (b) reducing extracellular Ca2+ concentration from 2.5 x 10(-3) M to 6.3 x 10(-4) M, (c) prior addition of sodium pentobarbitone (6.5 x 10(-4) M). The EC50 values for amrinone under conditions (a), (b), and (c) were 3.0 x 10(-3), 2.6 x 10(-3), and 2.8 x 10(-3) M, respectively. Force-frequency curves in rabbit papillary muscles were compared at normal (2.5 x 10(-3) M) and low (6.3 x 10(-4) M) extracellular Ca2+ concentration. Contractions at low frequencies of stimulation (less than 0.4 Hz) were less sensitive to removal of extracellular Ca2+ than higher stimulation rates indicating that in the former situation, recycling of intracellular Ca2+ is more important for maintaining contractile force.(ABSTRACT TRUNCATED AT 250 WORDS)

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Effects of amrinone, a cardiotonic drug, on calcium movements in dog erythrocytes.

Cited by 38 publications

References 18 publications

Milrinone

Milrinone

Developmental Changes in the Interactions of Amrinone and Ouabain in Canine Ventricular Muscle

Enhancement of Amrinone-induced Positive Inotropy in Rabbit Papillary Muscles with Depressed Contractile Function: Effects on Cyclic Nucleotide Levels and Phosphodiesterase Isoenzymes

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