Pulmonary Microcirculation in Experimental Model of Pulmonary Thromboembolism after Pretreatment with Chloroquine

Changes of pulmonary microcirculation in response to pulmonary artery embolization after pretreatment with chloroquine were studied on the model of isolated perfused rabbit lungs. The increase in the pulmonary vascular resistance and pre- and postcapillary resistance was less pronounced than after pulmonary thromboembolism after pretreatment with mibefradil (T-type Ca²⁺ channels blocker) or nifedipine (L-type Ca²⁺ channels blocker). The shifts of capillary filtration coefficient correlated with changes in the precapillary resistance. When modeling pulmonary thromboembolism after pretreatment with chloroquine combined with glibenclamide (K_ATP channels blocker), the studied hemodynamics parameters increased to the same extent as after pretreatment with nifedipine. The results indicate that chloroquine exhibits the properties of an L- and T-type Ca²⁺ channels blocker and an activator of K_ATP channels.