Perfluorochemical liquids do not stimulate endothelin-1 or nitric oxide production in human blood leukocytes

The purpose of these studies was to examine if perfluorochemical (PFC) liqu ids stimulate blood leukocytes to secrete nitric oxide (NO) and/or endothel in-1 (ET-1). As such, NO and ET-1 may modulate broncho- and vascular dilata tion and constriction, respectively, and thereby influence the clinical con dition of a patient in respiratory distress with persistent pulmonary hyper tension. Blood leukocytes in their natural habitat (whole blood) were incub ated in the presence of two different perfluorochemicals (perflubron and pe rfluorodecalin). The overall response in ET-1 or NO (indirectly measured as nitrite/ nitrate) production was examined at increasing PFC percentages (w t/vol) of PFC/whole blood. The lowest proportion used, 0.001% (wt/vol), was relevant to serum concentrations of PFC observed in liquid-ventilated indi viduals, whereas the highest proportion PFC, 50% (wt/ vol), would mimic a s ituation where leukocytes are presented to PFC-filled airways. Plasma level s of freshly drawn blood, similar to levels of incubated (6 h) non-PFC-supp lemented cultures, were ET-1 0.59 +/- 0.07 pg/ml (6 h +/- mean SEM) and NO2 -/NO(3)(-)50 +/- 9 muM(6 h). Perflubron or perfluorodecalin did not induce significant differences in ET-1 or NO2- /NO3- levels as function of PFC typ e or dose. In conclusion, PFC liquids do not stimulate production in leukoc ytes in vitro of substances that may modulate constriction or dilatation in the vascular and respiratory tract systems. Copyright (C) 2001 S.Karger AG , Basel.