The impact of nebivolol, carvedilol and propranolol on pulmonary microhemodynamics in case of experimental pulmonary thromboembolism in rabbits

BACKGROUND: Beta-adrenoblockers nebivolol, carvedilol and propranolol are used in clinical cardiology for the treatment of patients with ischemic heart disease. Pulmonary thromboembolism can develop in such patients. However, its unknown, what will be the pulmonary microcirculatory changes in case of pulmonary thromboembolism after pretreatment with beta-blockers. AIM: The comparative analysis of the pulmonary microhemodynamics changes following experimental pulmonary thromboembolism in rabbits after pretreatment with nebovolol, carvedilol and propranolol. MATERIAL AND METHODS: In 35 isolated perfused rabbit lungs we investigated the changes of pulmonary microcirculation in case of experimental pulmonary thromboembolism after pretreatment with 1-blocker nebivolol, combined blocker of 1- and 1, 2-adrenoceptors carvedilol, and blocker of 1, 2-adrenoceptors propranolol. RESULTS: After administration of 1, 2-adrenoceptors blocker propranolol and 1-blocker nebivolol the most of the pulmonary microcirculatory parameters increased. Combined 1-, 1, 2-blocker carvedilol caused mainly vasodilatory effects of the pulmonary arterial vessels, however, the pulmonary venous resistance increased. Pulmonary thromboembolism after pretreatment with beta-blockers caused pronounced increase of pulmonary artery pressure, precapillary and pulmonary vascular resistance. In that case after pretreatment with carvedilol capillary filtration coefficient was increased two times more than after propranolol administration; after pretreatment with nebivolol capillary filtration coefficient increased less, than after propranolol administration. CONCLUSIONS: Acute pulmonary embolism caused less pronounced increasing of capillary filtration coefficient in case of nebivolol administration, than after pretreatment with carvedilol and propranolol.