Continuous on-line hydrogen ion monitoring to study flow dynamics of perifusion systems and cellular metabolism

• Published in: The American journal of physiology Vol. 266; no. 5 Pt 1; p. E739
• Main Authors: Brand, R M, Ghazzi, M N, Rolfes-Curl, A, Cantor, H C, Midgley, A R
• Format: Journal Article
• Language: English
• Published: United States 01.05.1994
• Subjects: Carbonyl Cyanide m-Chlorophenyl Hydrazone - pharmacology; Cells - metabolism; Equipment Design; HeLa Cells; Humans; Hydrogen-Ion Concentration; Microelectrodes; Perfusion - instrumentation; Perfusion - methods; Syringes
• ISSN: 0002-9513; 2163-5773
• DOI: 10.1152/ajpendo.1994.266.5.e739

Time-dependent concentration profiles of input signals and feedback of metabolic products can strongly influence cellular responsiveness. To study these parameters, we developed a perifusion system that can deliver biological signals to cells with minimal dispersion, monitor real time responses, and remove waste products continuously. By monitoring pH with miniature hydrogen ion-selective electrodes at intervals of 1 s, effects of dispersion, flow rate, pumping system, and changes in cellular metabolism were demonstrated. Dynamic responses of a human cell line to a series of 10-min pulses of the metabolic uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) were monitored. A rapid 1-min increase in acid release occurred on exposure to CCCP, followed by a decrease in acidification and then a gradual return to a baseline slightly more acidic than before administration of CCCP. These observations demonstrate that this perifusion system can reveal small changes in pH (+/- 0.0005 units) induced by metabolic perturbations and has the potential to reveal the dynamics of cellular responsiveness to a wide range of hormonal, metabolic, and other chemical signals.