Fig. 6.

Doxycycline increases the turnover of LPA in blood but not S1P. A: Effect of doxycycline on the turnover of [³²P]LPA in circulation of rats. Rats with or without pretreatment of 50 mg/kg/day doxycycline (Dox) for 3 days were subjected to portal vein and hepatic artery ligation before experiment. Results from rats without ligation are also shown, n = 6. B: Effect of doxycycline on [³²P]LPA degradation in whole blood. Blood was collected from rats with or without pretreatment with 50 mg/kg/day doxycycline (Dox) for 3 days, and incubated with [³²P]LPA for the indicated time, n = 5. C: Removal of [³²P]S1P from the circulation of rats with or without portal vein and hepatic artery ligation. D: Removal of [³²P]S1P from circulation of rats with or without 50 mg/kg/day doxycycline treatment. E: Degradation of [³²P]S1P in whole blood from rats with or without 50 mg/kg/day doxycycline treatment. F: Effect of doxycycline on plasma S1P and LPA concentrations in mice with or without 100 mg/kg/day doxycycline treatment for 3 days, n = 6. Results are means ± SD. Significant differences between animals with or without doxycycline treatment are shown as * P < 0.05 and ** P < 0.01.