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| 1 | It was studied effect of activation of M-opioid receptor (OR) on the tolerance of isolated perfused rat heart to global 45 min ischemia and 30 min reperfusion. In vivo pretpeatment with selective M-opioid receptor agonist DAMGO (0,1mg/kg intravenously) increased tolerance of isolated perfused rat heart to ischemia and reperfusion. This effect was completely abolished by pretreatment with the M-antagonist CTAP. Addition of DAMGO and DALDA to the perfusion solution in a final concentration of 170 nМ before ischemia had no cardioprotective effect. However, addition of DALDA to the perfusion solution in a final concentration of 33 nM also decreased creatine kinase levels in the coronary sinus effluent. Keywords: M-оpioid receptors, isolated heart, ischemia, reperfusion | 1332 | ||||
| 2 | It has been established that the course administration (5 days at a dose of 16 mg/kg per os) of extracts of Aralia mandshurica or Rhodiola rosea decreased the incidence of ischemic and reperfusion ventricular arrhythmias during a 10-min coronary artery occlusion and a 10-min reperfusion. Extracts of Eleutherococcus senticosus, Leuzea carthamoides and Panax ginseng had no effect on the incidence of ischemic and reperfusion arrhythmias. Chronic administration of Aralia, Rhodiola and Eleutherococcus increased the ventricular fibrillation threshold (VFT) value in rats with postinfarction cardiosclerosis. Ginseng and Leuzea did not affect the VFT in rats with postinfarction cardiosclerosis. Keywords: phytoadaptogenes, heart, ischemia, reperfusion, cardiosclerosis, arrhythmias | 1383 | ||||
| 3 | Authors studied an impact of selective ligands of cannabinoid (CB) receptors on the contractility of the isolated perfused rat heart during global ischemia and reperfusion. A perfusion by solution containing the selective CB-agonist HU-210 exacerbated a cardiac contractility dysfunction. This cannabinoid decreased the left ventricular developed pressure, the maximal rate of contraction and relaxation of the heart during reperfusion but had no effect on the heart rate and the end diastolic pressure. Negative inotropic effect of HU-210 was transient and disappeared after 5 min reperfusion. The pretreatment with the selective CB1 receptor antagonist SR141716A and the selective CB2 receptor antagonist SR144528 had no effect on the myocardial contractility during reperfusion. In conclusion, the present results indicate that CB receptor stimulation can exacerbate reperfusion contractility dysfunction of the heart. Endogenous cannabinoids are not involved in the development of myocardial contractility dysfunction during ischemia/reperfusion of the heart. Keywords: cannabinoid receptors, cardiac contractility, ischemia, reperfusion, isolated heart | 1323 | ||||
| 4 | It has been found that intravenous administration of cannabinoids (ACPA, anandamide, methanandamide) solubilized in the mixture (cremophore EL : ethanol : 0,9% NaCl, 1:1:18) and Tocris water soluble emulsion of the same cannabinoids induced a completely identical negative chronotropic effect in chloralose-anesthetized rats. The selective CB1 and CB2 receptor agonist HU-210 (0.1 mg/kg) also induced a negative chronotropic effect in rats. Pretreatment with the CB1 receptor antagonist SR141716A (1 mg/kg) completely abolished this effect of HU-210. The CB2 receptor antagonist SR144528 (1 mg/kg) had no effect on the HU-210-induced bradycardia. Pretreatment with the ganglion blocker hexamethonium (10 mg/kg) also did not eliminate a negative chronotropic effect of HU-210 and ACPA. A 10-min perfusion of isolated rat heart by Krebs-Heseleit solution containing HU-210 in a final concentration 100 nM/L induced a decrease in the heart rate. It has been concluded that negative chronotropic effect of cannabinoids is mediated via an activation of cardiac CB1 receptors. Keywords: cannabinoids, heart rhythm | 1293 | ||||
| 5 | It has been found that occupancy of and ^-opioid receptors (ORs) by DPDPE and U-50488, respectively, prevents irreversible cardiac cell damage during global ischemia (45 min) and reperfusion (30 min) of the isolated perfused rat heart by the Langendorff technique. Activation of Kj-ORs decreased cAMP levels in the myocardium during reperfusion but stimulation of 8J-ORs had no effect on the cAMP levels. The occupancy of both types of receptors did not alter the cGMP levels before and after ischemia. Cardioprotective effect of DPDPE was completely abolished by pretreatment with cyclopiazonic acid, an inhibitor of Ca2+-ATPase of sarcoplasmic reticulum. Authors proposed that cardioprotective effect of U-50488 is mediated via a decrease in cAMP levels in the heart but cardioprotective effect of DPDPE is depended on the activity of Ca2+-ATPase of sarcoplasmic reticulum. Keywords: isolated perfused rat heart, ischemia, reperfusion, opioid receptors | 1190 | ||||
| 6 | In experiments with isolated perfused rat heart it was investigated cardioprotective effect of the selective and the nonselective cannabinoid receptor agonists during ischaemia and reperfusion at the final concentration of 0.1 and 1.0 mM. It was established that the CB1 agonist ACPA, the CB1- and CB2-receptor agonist HU-210 and the CB1- and CB2-receptor agonist СР 55,940 exhibit cardioprotective effect. The selective CB2-agonist JWH133 and the CB1- and CB2-receptor agonists anandamide and methanandamide did not exhibit cytoprotective effect. Cardioprotective effect HU-210 is depended on the activation of CB1-cannabinoid receptor. Keywords: Cannabinoid receptors, isolated heart | 1226 | ||||