Coinvolgimento polmonare e vascolare dell’ossido d’azoto nello shock endotossico nel suino

Septic shock is mainly characterized by systemic hypotension, pulmonary hypertension and acute lung injury probably due to an involvement of inducible nitric oxide synthase (iNOS). Because previous works have evidenced that administration of LPS (20 microng/kg/h i.v. for 240 min) failed to induce iNOS expression, in this study we tested the effects of a double dose of LPS in 2 groups of anesthetized, tracheostomized and mechanically ventilated Large White pigs. Besides main cardiovascular parameters (systemic and pulmonary arterial pressures, cardiac output and heart rate), we evaluated also the NO in expired air and iNOS expression in bronchial epithelium and pulmonary parenchyma. Results evidenced that double doses of LPS cause the same cardiovascular effects obtained with dose of 20 microng/kg/h, but in this case there was presence of NO in the expired air and the expression of iNOS in lung tissue was evident