Fig 1.
Proposed mechanism of accumulation of pimonidazole in hypoxic tissue regions.
Fig 2.
Representative mass spectrometric images of pimonidazole and its low-molecular mass metabolites and pimonidazole immunohistochemical staining in mouse tumors 0.5, 2 and 4 h after administration of pimonidazole.
The scale bar represents 1 mm. (A)–(F): Mass spectrometric images of mouse tumor 0.5 h after administration. (G)–(L): Mass spectrometric images of mouse tumor 2 h after administration. (M)–(R): Mass spectrometric images of mouse tumor 4 h after administration. (A), (G), (M): Mass spectrometric images of m/z 255.145, representing pimonidazole (1). (B), (H), (N): Mass spectrometric images of m/z 225.171, representing amino-pimonidazole (4). (C), (I), (O): Mass spectrometric images of m/z 239.150, representing nitroso-pimonidazole (2). (D), (J), (P): Mass spectrometric images of m/z 241.166, representing hydroxylamino-pimonidazole (3). (E), (K), (Q): Mass spectrometric images of m/z 530.239, representing the glutathione conjugate of amino-pimonidazole (6). (H), (L), (R): pimonidazole immunohistochemical staining.
Fig 3.
Representative mass spectrometric images of the glutathione conjugate of amino-pimonidazole and oxidized- and reduced glutathione in mouse tumors.
The scale bar represents 1 mm. (A)–(C): Mass spectrometric images of mouse tumor 0.5 h after administration of pimonidazole. (D)–(F): Mass spectrometric images of mouse tumor 2 h after administration. (G)–(I): Mass spectrometric images of mouse tumor 4 h after administration. (A), (D), (G): Mass spectrometric images of m/z 530.239, representing the glutathione conjugate of amino-pimonidazole (6). (B), (E), (H): Mass spectrometric images of m/z 308.091, representing reduced glutathione (GSH). (C), (F), (I): Mass spectrometric images of m/z 613.159, representing oxidized glutathione (GSSG).