Changes of Pulmonary Microhemodynamics in Experimental Pulmonary Thromboembolism after Pretreatment with K-Channel Activators.

Changes in pulmonary microhemodynamics in response to pulmonary embolism under conditions of activation of K channels with nicorandil, Kv channels with dapagliflozin, and BK channels with Evans blue were studied on isolated rabbit lungs. Under conditions of activation of K and BK channels, the constrictor reactions of the pulmonary arterial vessels during embolization of the pulmonary artery were less pronounced than in the control. Activation of BK channels reduced constrictor reactions of the pulmonary venous vessels, while activation of K and Kv channels eliminates them. The shifts of the capillary filtration coefficient are determined to a greater extent by the pre-/postcapillary resistance ratio, than by changes of the endothelial permeability. Pretreatment with dapagliflozin led to a decrease in the capillary filtration coefficient. It was established, that nimesulide exhibits properties of a BK-channel activator.