IN-VITRO TAURINE UPTAKE INTO CELL-CULTURE INFLUENCED BY USING MEDIA WITH OR WITHOUT CO2

Buffers used to incubate cells for pharmacological or toxicological st udies are usually of very simple composition, far from the composition of biological fluids or cell culture media. Comparative studies on ta urine uptake levels by cultured cells show that a new CO2-Independent Medium (CIM) is suitable for incubating cells in place of the Krebs-Ri nger buffer (KR) usually used. Basal uptake level of taurine was lower for cells incubated in CIM or in other culture media when compared to those incubated whether in KR or in other ''physiological buffers.'' Isoproterenol depressed similarly the taurine uptake in cells incubate d in CIM or KR. The same uptake modulation by beta-alanine, GES, GABA, or HEPES was observed for cells incubated in CIM or KR. C6 cells grow th in CIM was dependent on the starting cell density when classically vented T-flasks were used, growth being notably reduced at low density . In tightly closed flasks cells grew in CIM similarly to control cult ures maintained in M199 medium or DMEM. (C) 1998 Elsevier Science Inc.