Table 4. Mass spectrometry analysis of endogenous sphingosine, ceramide and sphingosine 1-phosphate in biopsies from pigs after inhalation of increasing doses of sphingosine. Levels of sphingosine, ceramide and sphingosine 1-phosphate (S1P) were determined in bronchoscopy biopsies from pigs 17 hrs after inhalation of 3.8 mL each of 0.9% NaCl, 0.125 % octylglucopyranoside (OGP), 10 μM, 125 μM, 250 μM and 1 mM sphingosine (SPH). Analyzed were each 1 sample/pig with 4 pigs per group. Protein concentrations on the small biopsies were too low to get reliable protein values and we therefore normalized for sphingomyelin, since the studies with d7-sphingosine show that inhalation of sphingosine does not result in a significant change of sphingomyelin. Given is the mean SD of each parameter from 4 pigs per group, *p < 0.05, **p < 0.01, ***p < 0.001, ANOVA