Endothelial cells supply phosphate to odontoblasts. (A) Principal component analysis of metabolome profiles of dental pulp samples from control or Vegfr2^iΔEC mice at P12 (control [Cont] n = 4, Vegfr2^iΔECn = 4). PC, principal component. (B) Volcano plot analysis of metabolites in Vegfr2^iΔEC mice relative to control mice. Red plots represent key metabolites of ketone body metabolism or energy metabolism. Mice were injected with H₃P[¹⁸O]₄ to trace phosphate delivered by blood vessels. (C) Relative intracellular metabolite levels quantified by IC-MS (peak area/internal standard (IS)/tissue-mg; Cont n = 4, Vegfr2^iΔECn = 4). (D) Relative amounts of H₃PO₄ and H₃PO[¹⁸O]₄ were quantified by IC-MS analysis (Cont n = 4, Vegfr2^iΔECn = 4). (E) IMS visualizing the amounts and localizations of phosphoric acid, pyrophosphate, and triphosphoric acid (PPPi). Scale bar: 200 μm. Data are presented as means ± SD. Comparisons between two groups were evaluated using a two-sided Student’s t test.