Jpn. J. Pharmacol. 74 (2), 213-216 (1997)

Quenching of Nitric Oxide by an Oral Carbonaceous Adsorbent

Noriko Iwamoto (1), Katsumi Ito (1), Junji Kakuchi (2) and Toshimasa Yoshioka (1,3)

(1) Department of Pediatric Nephrology, Kidney Center, and (3) Department of Pharmacology, Tokyo Women's Medical College, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162, Japan
(2) Biomedical Research Laboratories, Kureha Chemical Industry Co., Ltd., 3-26-2 Hyakunin-cho, Shinjuku-ku, Tokyo 169, Japan

Abstract: The ability of carbonaceous particles (AST-120), originally developed as an enteral adsorbent of uremic toxins, to quench nitric oxide (NO) was tested. NO in solutions prepared by two methods [NO gas bubbling and NO generating system, i.e., decomposition of 1-hydroxy-2-oxo-3-(aminopropyl)-3-isopropyl-1-triazene] were determined by a NO-specific reduction of carboxy-2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide using an electron paramagnetic resonance spectrometry. NO concentrations were less in samples containing increasing concentrations of AST-120. In a separate study, nitrite concentrations in lipopolysaccharide-treated RAW264 cells were significantly less in incubation medium containing AST-120. Thus, AST-120 may be applicable as an enteral anti-NO agent.

Keywords: Carbonaceous adsorbent, Nitric oxide, Inflammatory bowel disease