Modulatory effects of diltiazem on inotropic responses to amrinone on rabbit isolated atria.
نویسندگان
چکیده
The effect of pretreatment with graded concentration of diltiazem on the inotropic responses to amrinone were studied on isolated atria of rabbit. The responses to amrinone were modified by diltiazem in a biphasic manner; initial potentiation followed by inhibition. The potentiation is proposed to be due to synergistic rise in cytosolic calcium ion concentration by diltiazem and amrinone. The inhibition by diltiazem in higher concentration may be due to blockade of calcium ion influx and depletion of intracellular calcium ion from storage sites.
منابع مشابه
Inotropic and Chronotropic Effects of 6-Hydroxy-4- Methylquinolin-2(1H)-One Derivatives in Isolated Rat Atria
Background: Selective phosphodiesterase (PDE3) inhibitors improve cardiac contractility and may use in congestive heart failure. However, their proarrhythmic potential is the most important side effect. Methods: In this research, we evaluated the potential cardiotonic activity of six new synthesized selective PDE3 inhibitors (6-hydroxy-4-methylquinolin-2(1H)-one derivatives) using the spontan...
متن کاملCardiac and vascular effects of diltiazem, dobutamine and amrinone, drugs used after myocardial revascularization.
Hemodynamic care during postoperative management of myocardial revascularization should include vasorelaxing drugs to insure adequate graft and coronary flow, and stimulation of stroke volume to maintain vascular perfusion pressure. We tested the cardiac (inotropic and lusitropic) and vascular (relaxant) effects of diltiazem (0.1 nM to 0.1 mM), dobutamine (10 microM to 10 mM) and amrinone (10 m...
متن کاملNovel cilostamide analogs, phosphodiesterase 3 inhibitors, produce positive inotropic but differential lusitropic and chronotropic effects on isolated rat atria
Objective(s): Recently, we showed that some new synthetic compounds structurally related to cilostamide (4-(1,2-dihydro-2-oxoquinolin-6-hydroxy)- N-cyclohexyl-N-methylbutanamide), a selective phosphodiesterase 3 (PDE3) inhibitor, produce inotropic effect comparable to that of IBMX (3-isobutyl-1-methylxanthine), a non-selective PDE inhibitor, but with differential chronotropic effect. In this in...
متن کاملInotropic and chronotropic effects of new cilostamide derivatives on isolated rat atria
Introduction: It was shown in a previous study, that MCPIP, a cilostamide derivative, increased atrial contraction force without changing contraction rate. To improve this property, two new derivatives of cilostamide were synthesized and their effects on PDE3 activity and isolated rat atria contraction were investigated. Methods: The inhibitory effect of each compound on PDE3 enzyme was dete...
متن کاملEffects of magnesium on isolated rabbit atria.
The cardiac effects of magnesium were studied on 40 spontaneously beating rabbit atria at 37 degrees C. Magnesium administered in doses of 30, 60, 120 and 240 mmol elicited dose dependent negative inotropic and chronotropic responses. Larger doses above 240 mmol caused complete atrial arrest. Further it was observed that propranolol with magnesium became more effective in blocking the positive ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Indian journal of physiology and pharmacology
دوره 42 2 شماره
صفحات -
تاریخ انتشار 1998