Effects of pH on murine insulinoma βTC3 cells

Confluent monolayer cultures of βTC3 cells were exposed for 4 h to acidic, neutral, or alkaline pH media. Studies determined the impact of pH on viability, insulin secretion rate, glucose consumption rate, lactate production rate, and ATP content. Cell viability was not affected by exposure to media of different pH (> 95% for all groups). Insulin release from cells exposed to acidic media (pH of 6.4) was ~ 75% higher than that from cells exposed to either neutral (pH of 7.1) or alkaline (pH of 7.8) conditions. Conversely, ATP content was significantly reduced in cultures exposed to acidic conditions, although there was no statistical difference between neutral and alkaline conditions. Glucose consumption and lactate production rates increased linearly with increasing pH. (C) 2000 Academic Press.