The effect of hexose on chloramphenicol sensitivity and resistance in chinese hamster cells

✍ Scribed by Michael L. Ziegler; Richard L. Davidson

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 632 KB
• Volume: 98
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040980321

✦ Synopsis

Abstract

The toxicity and extent of growth inhibition produced by chloramphenicol (CAP) in CAP^s^ Chinese hamster cells (line V79‐5) was found to be dependent on the type and concentration of hexose in the medium. In high levels of glucose (6.5 mM), cultures of CAP^s^ cells underwent 7–8 population doublings in the presence of 100 μg/ml CAP and viability then dropped rapidly. In contrast, lower concentrations of glucose (1.0 mM) permitted only limited growth (2–3 doublings) in the presence of 100 μg/ml CAP, but the cells remained viable and apparently quiescent for prolonged periods of time. The growth potential of V79‐5 cells in CAP appeared specifically dependent on glucose, as mannose and galactose could not substitute for glucose. The toxicity of CAP to these cells seemed to be determined primarily by the number of cell doublings in the presence of the drug.

A CAP^R^ derivative of V79‐5, designated 5‐3, was analyzed in order to determine whether the requirement for glucose for cell growth in the presence of CAP also occurred in cells that were isolated as resistant to the drug. In order to rigorously control the hexose in the medium, some experiments were performed with medium containing dialysed, instead of whole, fetal calf serum. It was seen that the growth of the CAP^R^ line in the presence (but not the absence) of 100 μg/ml CAP was dependent on glucose in the medium. Thus, resistance to CAP in these cells appears to be a conditional state, dependent on glucose for expression. Furthermore, the glucose auxotrophy of these cells in the presence of CAP suggests that CAP is still affecting some activities in cells isolated as CAP^R^.