The effect of pH on growth, protein synthesis and lipid-rich particles of cultured mammalian cells

• Main Authors: Cosmo G. Mackenzie, Sc. D, Julia B. Mackenzie, Paul Beck
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1961
• Subjects: Carbonic acid
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.283.3510

A simple procedure has been established for controlling and measuring the pH of media in which the bicarbonate-carbonic acid system is the predominant buffer. The HCO-3 concentration was maintained at 22.5 mM and the H2COa concentration was varied by equilibrating the media with 0.5 to 40 per cent CO2 in air. The curve relating extracellular pH to 3 day cell growth was similar for glass-attached HeLa and Chang liver cells. Maximum growth occurred over a pH range of 7.38 to 7.87. Cell growth declined precipitously on the alkaline side and more gradually on the acid side of the optimal pH range. Comparable pH growth curves were also obtained with newly isolated cells from rat liver and skeletal muscle. It was shown that the effect of pH on growth was independent of the CO2 concentration and that the essential nutrients in the medium were stable over the pH range studied. Although alkalosis depressed the 3 day cell population, cells exposed to a pH of 8.0 to 8.2 grew at the maximal rate for the first 12 to 24 hours. Growth then ceased abruptly and the cells entered a steady state with respect to net protein synthesis. This was followed by cytoplasmic retraction and cell death. Increasing the concentrations of calcium or magnesium in the