The role of glutamine, serum and energy factors in growth of enterocyte-like cell lines

Background: Glutamine is routinely added to most cell cultures. Glutamine h as been found to be the preferential nutrient to the rapidly replicating in testinal mucosa, but whether this isa metabolic effect or due to other prop erties of this amino acid is not determined. To study the importance of glu tamine on the growth of two enterocyte-like cell lines, the effects of depr iving the media or supplementing it with glutamine were assessed in media w ith different serum and energy supplements. Methods: CaCo-2 and HT-29 cells were grown in serum-free medium, with fetal bovine or synthetic serum, and with or without glucose or galactose. The glutamine content was varied bet ween 0 and 4 mM. All growth assays were performed in triplicate by counting in a hemocytometer. Results: Both cell lines were dependent of serum facto rs for growth, but displayed distinct requirements on glutamine supplementa tion. Glutamine was an obligate supplement with dose-dependent correlation to growth (r = 0.87, p < 0.01) for CaCo-2 cells cultured in synthetic, but not in fetal bovine serum. In HT-29 cells, the correlation between glutamin e and growth was significant (r = 0.68, p < 0.05) only in fetal bovine seru m in the absence of galactose. Conclusion: This study shows that glutamine has different growth stimulating effects on two enterocyte-like cell lines studied. This could reflect different modes of action of glutamine on proli feration and differentiation in an enterocyte cell population. (C) 1998 Els evier Science Ltd. All rights reserved.