Possibilities of medical correction of vascular disorders in lungs during chronic obstructive pulmonary disease formation (experimental study)
The model of chronic obstructive pulmonary disease (COPD) was reproduced in rats by intermittent inhalation of nitrogen dioxide for 60 days. Evidence of vascular disorders was assessed by pulmonary perfusion scintigraphy and determination of pulmonary artery smooth muscle reactivity under the action of agents-vasodilators. Disorders of pulmonary capillary blood flow occurred at an early stage of COPD (15 days) and extended not only to segments but lobes of lungs by the 60-th day of exposure. Dilatability of pulmonary arteries reduced that was reflected in reduction of the amplitude of smooth muscle relaxation in response to vasodilators with different mechanisms of action. Starting with the 30-th day rats were treated with angioprotective drugs - rosuvastatin and sulodexide for correction of vascular disorders. Rosuvastatin had no positive effect on pulmonary microcirculation and the state of smooth muscle reactivity of pulmonary arteries. The result of sulodexide administration was improvement of pulmonary microcirculation with the inclusion of reserve areas in perfusion. Dilatability of pulmonary arteries increased that was manifested in enhancing smooth muscle relaxation in response to administration of isoproterenol and especially nitrosorbid. We can obviously speak about the restoration under the influence of sulodexide NO-dependent mechanism of pulmonary artery smooth muscle relaxation and partial restoration of β-adrenergic vasodilatation.