The effect of medium pH on rate of growth, neurite formation and acetylcholinesterase activity in mouse neuroblastoma cells in culture

Abstract

Cell division, neurite formation and acetylcholinesterase activity were examined in a clone (NBA2) of mouse neuroblastoma cells maintained for up to 120 hours in medium with pH values between 6.6 and 8.0. Growth rate decreased as pH was reduced from 7.8 to 6.6. Generation time at pH 7.4 was 25 hours, while the rate of cell division was negligible at pH 6.6. The total number of cells at stationary phase was less at the lower pH values. Neurite formation was enhanced markedly as the pH was reduced from 7.4 to 6.6. Acetylcholinesterase activity was 5- to 8-fold greater in cells exposed to medium at pH 6.6 than in cells maintained in medium at pH 7.4. The reduction in the rate of cell division and increases in neurite formation and acetylcholinesterase activity at pH 6.6 were reversible upon exposure of the cells to pH 7.4 medium. Cell viability was greater than 90% at all medium pH values over a period of 120 hours. Uncloned T-59 mouse neuroblastoma cells were affected similarly by changes in pH. These results show that manipulation of the environmental pH can reversibly alter growth, neurite formation, and acetylcholinesterase activity of mouse neuroblastoma cells in culture.

Effects of Hydergine on Aging Neuroblastoma Cells in Culture

“…The greater effect in low pH medium may reflect more extensive pigment formation at this pH. Reduced cell growth and increased neurite formation at low pH reported here is in agreement with earlier studies (2).…”

“…Cells were cultured in medium having a pH of 7.3-7.4 (regular medium) and in medium having a pH of 6.6-6.8 (low pH medium) (2). Cells in either regular or in low pH media were trated with Hydergine in various concentrations for 8 days, and at the end of this time cell viability, cell number, neurite formation and lipofuscin pigment formation were assessed by the methods described above.…”

“…Mouse CI300 neuroblastoma cells were cultured according to methods described previously (2,11). Cells were routinely subculturcd every 4 or 5 days in order to maintain the cells in logarithmic growth; cell doubling time varied between 19 and 26 h. Cells were harvested lor transfer or for analysis by exposure for 6 min at 36 °C to 2 ml of 0.25% Viokase (Gibco) in phosphate-buffered saline (PBS; 8.0 g NaCl, 0.2 g KCl, 2.8 g NaaHP04 • 12HaO, 2 g KHaP04 in distilled water to give 1 liter).…”

Modulation of sprouting in organ culture after axotomy of an identified molluscan neuron

“…In addition, cell culture studies suggest that the optimum pH of the medium for neurite outgrowth of molluscan neurons occurs between pH 7.5-8.2 (Kostenko, Musienko, and Smolikhina, 1983). In contrast to these studies, decreasing extracellular pH from 7.4 to 6.6 has been shown to stimulate neurite outgrowth from neuroblastoma cells (Bear and Schneider, 1977). Although changes in intracellular pH have been postulated to be important as a potential regulator of growth (Boron, 1984), this viewpoint has been challenged (Thomas, 1989), and our results suggest that an elevation in intracellular pH blocks the initiation of neurite outgrowth.…”

The effect of environmental pH on polymeric transfection efficiency

“…, approximately pH 6.4-6.8 for solid tumors [33], pH 6.4 for brain ischemia [31], and pH 6.8 for heart ischemia [32]). The extracellular pH can modulate various biological functions, such as gene expression [34], growth rate [35], viability [36], cellular uptake [37], endocytosis [37, 38], exocytosis [38], and lysosomal trafficking [39]. However, the effects of pH on polymeric transfection have rarely been studied.…”