Inhaled Nitric Oxide Reverses Vascular and Respiratory Effects of ET-1 and PAF in Pigs

[摘要] In anaesthetized paralysed, mechanically ventilated pigs, thevascular and respiratory effects of 80 ppm nitric oxide (NO) inhaledfor 6 min were evaluated. To evoke different levels of smoothmuscle contraction ET-1 or PAF, mediators involved in pulmonarydisorders, were used. In control conditions, inhaled NO causedselective pulmonary vasodilatation without affecting respiratoryresistances. This pulmonary vascular activity influenced thedistensibility of the respiratory system and decreased inspiratorywork. ET-1 administration significantly increased pulmonary arterialpressure and modestly changed mechanical properties of therespiratory system, while PAF caused potent vasoconstriction andbronchoconstriction associated with a marked change involume-pressure relationship. In both cases, the changes in vascularand mechanical properties of the respiratory system increasedinspiratory work. The vascular and respiratory activities of inhaledNO were correlated with preconstriction levels. The data show thatthe combination of vascular and respiratory effects improvespulmonary function, suggesting that inhalation of NO is a possibletherapeutic approach for obstructive and inflammatory pulmonarydiseases.

[学科分类] 生理学与病理学