Comparison of the Tetrazolium Salt Assay for Succinate Dehydrogenase with the Cytosensor Microphysiometer in the Assessment of Compound Toxicities

✍ Scribed by Deirdre Cooke; Richard O'Kennedy

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 106 KB
• Volume: 274
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1999.4274

✦ Synopsis

The cytosensor microphysiometer (a biosensing instrument for detecting cellular metabolism) was compared to the established tetrazolium salt assay as a chemosensitivity test. Two coumarin compounds, 7-hydroxycoumarin and esculetin, were examined to determine their effect on the cellular metabolism of A431 cells over a 24-h exposure period. In the tetrazolium salt assay, 7-hydroxycoumarin caused suppression of the succinate dehydrogenase activity at concentrations greater than 10 g/ml. Esculetin exerted a more serious effect on succinate dehydrogenase, with decreases in activity observed at greater than 1 g/ml. The observed effect was dose-dependent for both compounds examined. The metabolic activities of cells exposed to 100 g/ml of drug were 90.37 ؎ 2.8 and 71.62 ؎ 2.96 (n ‫؍‬ 3), of control values, for 7-hydroxycoumarin and esculetin, respectively. Using the cytosensor microphysiometer to assess metabolic activities, a similar pattern of inhibition was observed, with esculetin more detrimental to cellular metabolism than 7-hydroxycoumarin. The effect was dose-and time-dependent for both compounds. 7-Hydroxycoumarin (100 g/ ml) caused the cellular metabolic rate to drop to 44.21 ؎ 5.34% (n ‫؍‬ 4) of the control metabolic rate, while 100 g/ml esculetin caused the metabolic rate to fall to 21.5 ؎ 4.54% (n ‫؍‬ 4) of the control rate. The cytosensor method proved to be superior to the tetrazolium salt assay for a number of reasons, which are discussed in this paper.