抄録
It has been reported that adipocytes accumulate triglycerides and concurrently produce adiponectin, a beneficial adipocytokine, to assist insulin function, and conversely produce unbeneficial adipokines, which have negative effects on the organism. We previously reported that the production of fumaric acid increases under hyperglycemic conditions due to mitochondrial stress and that fumaric acid reacts with the thiol group of cysteine residue to form S-(2-succinyl)cysteine (2SC), which inhibits adiponectin secretion and modifies a variety of proteins, resulting in the dysfunction of adipocytes. Therefore, we considered that a simple measurement of fumaric acid produced by adipocytes would enable rapid evaluation of metabolic abnormalities in adipocytes, and investigated a measurement system for this purpose. After culturing adipocytes for 4 days, a decrease in pH was observed due to the production of organic acids. Hydroxylamine hydrochloride and iron (III) chloride, a reagent for carboxylic acid detection, reacted with fumaric acid, malic acid, and citric acid. Similarly, fumaric acid levels by the enzymatic method and organic acids were found to be elevated by the carboxylic acid qualitative reagent in the medium in which adipocytes were cultured. Therefore, it was confirmed that functional abnormalities of adipocytes can be easily evaluated by the carboxylic acid qualitative reagent.
