Effect of chronic intermittent, chronic sustained and chronic sustained plus intermittent LPS treatment on FGF23 expression. Chronic intermittent treatment consisted of a 3.3 μg/kg i.p. LPS injection daily for 2 weeks. Chronic sustained treatment consisted of subcutaneous sustained-release LPS pellets delivering 2 mg/kg/day for 2 weeks. Chronic sustained plus intermittent treatment consisted of sustained-release LPS pellets as above plus 3.3 μg/kg i.p. LPS on the day of sacrifice. All mice were sacrificed 5 h after the last injection. Plasma levels of (A) C-terminal FGF23, (B) intact FGF23, (C) TNF-α and (D) NGAL. Data are presented as mean ± SD, n = 5 per group. * P < 0.05 versus control, ** P < 0.01 versus control, *** P < 0.001 versus control on ANOVA. (E) Effect of chronic sustained plus intermittent LPS treatment on FGF23 expression in mice with and without spleen, n = 5 per group. * P = 0.02 versus asplenic mice.