<p>S1P concentrations in plasma (<b>A</b>) or lung tissue lysate (<b>B</b>) or C5a concentrations in plasma (<b>C</b>) or lung tissue lysates (<b>D</b>) from <i>Sphk1</i><sup>+/+</sup> or <i>Sphk1<sup>−/−</sup></i> mice were determined before or after i.p. LPS challenge (0.5 mg/kg), using the LC-MS/MS (46) or ELISA techniques. Error bars represent s.d. *p<0.005, **p<0.001, by Student's t-test. No significant differences in (<b>B, C, D</b>). n = 10 for each genotype and time point.</p
