Sympathetic mechanism regulating cardiac function during transient coronary insufficiency of varied duration

Литвицкий, Петр Францевич

doi:10.1007/bf00829769

Cited by 2 publications

(2 citation statements)

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“…The platform was carefully isolated from the adjacent tissues and the nerve was cooled to 6~ with a cooling fluid propelled by a vacuum pump for 5 min before CO and during the ischemia and reperfusion periods; series V (n=10) --CO as in series IV without DSLET; series VI (n=8) --CO+DSLET+ transection of the VN on the neck 5 min before CO; 0007-4888/99/0002-0148522.00 ~|999 Kluwer Academic/Plenum Publisllers and series VII (n=12) --cardiac sensitivity to norepinephrine (NE) was assessed by changes in the left ventricular pressure, dynamics of the chronotropic reaction, and the integral index of cardiac activity [ 12] in response to a standard dose of NE (1 ~g/kg) injected into the right ventricle before and on minutes 5 and 15 of DSLET or Ringer's solution infusion. The cardiac reactions were analyzed 20 and 180 sec postinjection corresponding to the maximum and minimum heart responses [5]. The significance of differences was evaluated by the Z2 and sign tests.…”

Section: Methodsmentioning

confidence: 99%

Role of σ-opiate receptors in development of ischemic arrhythmias

et al. 1999

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In acute experiments on anesthetized cats, the selective 5-opiate receptor agonist DSLET has a pronounced antiarrhythmic effect on ischemic heart rhythm disturbances. This eftect is probably related to inhibition of the sympathetic heart rhythm regulation, because the antifibrillation effect of DSLET is not mediated via the vagus nerves, but on the other hand DSLET considerably modulates cardiac adrenoreactivity. Key Words: DSLET; f-opiate receptors; myocardial ischemia; cardiac arrhythmias; autonomic nervous systemNonselective agonists of opiate receptors (OR) dalargin (5-and ~t-receptors) and 13-endorphin (5-, 5-, E-, and n-receptors) produce an antiarrhythmic effect in ischemic myocardium under conditions of preserved autonomic innervation of the heart [6][7][8]. However, it is unclear what specific role in the antiarrhythmic effect is given to particular type of OR. Our aim was to study the effect of the selective 6-opiate receptor agonist DSLET on the development of ischemic arrhythmias and the role of the autonomic nervous system in this process. MATERIALS AND METHODSExperiments were carried out on 67 cats of both sexes weighing 2-4 kg anesthetized with Nembutal (40 mg/kg intraperitoneally). Myocardial ischemia was produced by clamping the circumflex branch of the left coronary artery near its orifice with the help of a controllable tourniquet. The development of arrhythmias was observed during 15-rain arterial occlusion and subsequent 15-min reperfusion periods. Under these conditions, idioventricular rhythm disturbances were observed in 72% animals, while ventricular tachycardia and ventricular fibrillation developed in 28 and 55% Russian State Medical University, Moscow cats, respectively [6]. ECG and blood pressure in femoral artery were recorded with a Biocomb-8 polyphysiograph (Orion/EMG). Single and grouped extrasystoles, ventricular tachycardia, and ventricular fibrillation were recorded and analyzed. The selective 5-OR agonist DSLET (Laboratory of Peptide Synthesis, Russian Cardiology Research-and-Production Complex) was infused intravenously in a dose of 20 Ixg/kg during the coronary occlusion (CO) period. Seven experimental series were carried out: series I (n=9) --CO and infusion of DSLET under conditions of intact cardiac innervation; series II (n=8) --CO+ DSLET + transection of the vagus nerves (VN) on the neck and cardiac branches of the stellate ganglia (5 min prior to CO); series III (n=10) --CO+cardiac denervation as in series II without DSLET; series IV (n=10) --CO+DSLET+differential block of myelinated VN fibers (cooling to 6~ [13]). To this end VN was separated from sympathetic nerves and placed on a cooling plattorm with a thermistor recording the nerve temperature. The platform was carefully isolated from the adjacent tissues and the nerve was cooled to 6~ with a cooling fluid propelled by a vacuum pump for 5 min before CO and during the ischemia and reperfusion periods; series V (n=10) --CO as in series IV without DSLET; series VI (n=8) --CO+DSLET+ transection of the VN on the neck 5...

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Section: Methodsmentioning

confidence: 99%

Role of σ-opiate receptors in development of ischemic arrhythmias

et al. 1999

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“…Norepinephrine was injected into the right ventricle before a dropwise infusion and on the 5th and 15th minutes of the infusion of BE or Ringer's solution. Cardiac reactions were analyzed 20 see (the maximum cardiac response phase) and 180 sec (the cardiac response decay phase) after the administration of norepinephrine [4]. BE was obtained from the Laboratory of Peptide Synthesis of the Cardiology Research-and-Production Center.…”

Section: Methodsmentioning

confidence: 99%

Effects of β-endorphin on cardiac afferent systems

et al. 1998

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Studies performed on cats have shown that the antifibdUatory effect of 13-endorphin under acute myocardial ischemia is mediated by afferent pathways of the vagus nerves and sympathetic components of arrhythmogenesis. This effect is associated with the ability of 13-endorphin to change the impulse activity of cardiovascular and integrative neurons of the nodose ganglion. Key Words: ~-endorphin, vagus nerves, nodose ganglion, myocardial ischemia, cardiac adrenergic reactivityClinical and experimental data point to a relationship between the severity of ischemic heart disease and the decrease in the plasma level of 13-endorphin (BE). A moderate increase in the BE content is generally associated with good prognosis in patients with myocardial ischemia [1,2,5]. Our previous studies revealed a protective effect of BE in respect of the development of isehemic ventricular fibrillation. Bilateral vagotomy abolished this effect [9]. Vagotomy interrupts the conduction of impulses over afferent and efferent pathways of the vagus nerves CON). Therefore, it is unclear what a pathway mediates the antifibrillatory effects of BE. Cardiac afferent systems play an important role in the pathogenesis of ischemic ventricular fibrillation. This work was designed to determine the role of vagal afferents in the antiarrhythmic effect of BE. MATERIALS AND METHODSExperiments (n=82) were performed on male and female eats weighing 2-4 kg narcotized with Nembutal (40 mg/kg intraperitoneally). Myocardial ischemia was induced by ligation of the left circumflex coronary artery at the site of its origin from the main branch. The development of arrhythmia was observed during 15-min arterial occlusion and 15-min Russian State Medical University, Moscow reperfusion. Under these conditions idioventricular rhythm, ventricular tachycardia, and ventricular fibrillation were observed in 72%, 28%, and 55% of animals, respectively [7]. Electrocardiogram and blood pressure in the femoral artery were recorded with a BIOKOMB-8 polyphysiograph (ORLON/ EMG). Single and multiple extrasystoles, ventricular taehyeardia, and ventricular fibrillation were considered in the analysis of arrhythmia.In the lust series of experiments, 8 cats were subjected to coronary artery occlusion accompanied by the injection of BE under differentiated blockade of the impulse conduction along myelinated VN fibers induced by cooling VN to 6"C [11]. Cervical VNs were separated from the sympathetic nerves and placed on a special nerve-cooling device equipped with a thermistor registering the nerve temperature. These nerves were thoroughly isolated from surrounding tissues. The nerve temperature was lowered using a cooling liquid which was pumped with a vacuum device 5 min before coronary artery occlusion and during ischemia and 15-min reperfusion. In the second series of experiment, 10 cats were subjected to similar procedures without administering BE. In the third series of experiments (24 animals), the pulse activity of the nodose ganglion neurons was extracellularly registered with a ...

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Sympathetic mechanism regulating cardiac function during transient coronary insufficiency of varied duration

Cited by 2 publications

References 2 publications

Role of σ-opiate receptors in development of ischemic arrhythmias

Role of σ-opiate receptors in development of ischemic arrhythmias

Effects of β-endorphin on cardiac afferent systems

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