[Effect of cigarette smoke extract on hypoxic pulmonary vasoconstriction]

Using an intravital microscopic-video recording TV system, we observed change in microvascular internal diameter (ID) of surface lung and mean pulmonary arterial pressure (Ppa) in Wistar rats (n = 60) in vivo during hypoxic ventilation (Fi02 = 0.1, 3 min) before and after intravenous administration of cigarette smoke extract (CSE). Our results showed that: (1) ID of pulmonary arterioles venules significantly decreased during acute alveolar hypoxia (P less than 0.001 vs control). After pretreatment of animal with administration of CSE intravenously, much more remarkable pulmonary vasoconstriction was induced by hypoxia than before CSE injection. (2) During hypoxia Ppa increased by 13.53 percent before administration of CSE (less than 0.001 vs control), and by 30.57 percent after CSE (P less than 0.001 VS control and before CSE), respectively. The data suggested that CSE can strengthen pulmonary vasoconstriction and hypertension induced by acute alveolar hypoxia.