Cardiotonic action

ZO049 Kobayashi, M., Y. Ishida, N. Shoji, and ZO059 Y. Ohizumi. Cardiotonic action of [8]-gingerol, an activator of the Ca -pumping adenosine triphosphate of sarcoplasmic reticulum, in guinea pig ZO060 atrial muscle. J Pharmacol Exp Ther 1988 246(2) 667-673. 

Some of these workers also studied the mode of action of dobutamine in 22 patients recovering from coronary artery bypass surgery. It was found that an infusion of calcium chloride (1 mg/kg per minute initially, then 0.25 mg/kg per minute) reduced the increase in cardiac output produced by an infusion of dobutamine 2.5 to 5 micrograms/kg per minute by 30%. In a group of 24 similar patients the cardiotonic actions of amri-none (a phosphodiesterase inhibitor) were unaffected by the calcium infusion. ... 

Sziegoleit W, Weiss M, Fahr A, Scharfe S. Trapidil does not affect serum levels and cardiotonic action of digoxin in healfliy humans. Jpn CireJ (1987) 51,1305-9. 

Documented effects Giving an infusion of the plant to laboratory animals resulted in cardiotonic action and a mild decrease of blood pressure. In experiments with dogs the preparation decreased blood coagulabihty (Ibragimov and Dzhumabaev... 

The genus Eucomis is indigenous to southern and eastern Africa. The widespread E. autumnalis (Mill.) Chitt. (Syn. E. undulata Ait.) has been used by native medical doctors against rheumatism, veneric, mental and many other diseases. A cardiotonic action has not been observed (75). A botanical survey revising this genus had been published by Reyneke in 1972 61). 

Further investigations on red cells have confirmed these views (Fig. 1). Scilla-ren A is the most powerful inhibitory compound, being effective on Na and K transport at concentrations as low as 10 M. Its activity is 2unsaturated glycoside this substantiates the idea that an active glycoside must possess an unsaturated resonant ring, partly electrophilic in character. The same molecular features have been shown to be necessary for cardiotonic action. 

Enoximone (113), an imidazdinone-containing molecule, is a cardiotonic molecule like imazodan above. Its mechanism of action is still not established but it is repotted to be a potent... 

Discuss the uses, general drug action, general adverse reactions, contraindications, precautions, and interactions of the cardiotonic and inotropic drugs. 

Cardiotonic drugs increase the force of the contraction of the muscle (myocardium) of the heart. This is called a positive inotropic action. When the force of contraction of the myocardium is increased, the amount of blood leaving the left ventricle at the time of each contraction is increased. When the amount of blood leaving the left ventricle is increased, cardiac output (the amount of blood leaving the left ventricle with each contraction) is increased. 

When a cardiotonic drug is administered, die positive inotropic action increases the force of die contraction, resulting in an increased cardiac output. When cardiac output is increased, the blood supply to die kidneys and otiier vital organs is increased. Water, electrolytes, and waste products are removed in adequate amounts, and tiie symptoms of inadequate heart action or HF are relieved, hi most instances, the heart rate also decreases. This occurs because vital organs are now receiving an adequate blood supply because of the increased force of myocardial contraction. 

The pyrimido[5,4-6][l,4]oxazin-4-ones (210) are of potential use as cardiotonics <87EUP228094>. Some pyrimido[5,4-6][l,4]oxazin-4-ones (211) were tested for ionotropic activity and chosen for preclinical tests. The biochemical and pharmacological data show that the mechanism of action differs from that of other comparable substances <90EJM333>. 

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