EFFECT OF L-CARNITINE AND ACYLCARNITINE DERIVATIVES ON THE PROLIFERATION AND MONOCLONAL-ANTIBODY PRODUCTION OF MOUSE HYBRIDOMA CELLS IN CULTURE

The effect of L-carnitine (Cn) on cell growth metabolism and antibody production rates was investigated using the murine hybridoma cell line , Mark3, in batch and fed harvest cultures. Two acylcarnitine derivati ves were also tested: palmitoyl L-Cn and acetyl-DL-Cn. The addition of 20 mu M L-Cn to cultures of Mark3 hybridoma cells that had been adapt ed to L-Cn significantly stimulated monoclonal antibody (mAb) producti on without affecting cell growth. In contrast, mAb secretion slightly decreased when L-Cn was added to culture of cells that had not been ad apted to L-Cn. Palmitoyl L-Cn also stimulated mAb production by adapte d cells, whereas the acetyl-DL-Cn, reduced mAb secretion. The presence of L-Cn in the medium did not affect glucose consumption or lactate p roduction, but the metabolism of some amino acids was altered. The med ium concentrations of valine, leucine, isoleucine and lysine were enha nced from 22% to 41% according to amino acids, whereas those of alanin e, glycine and proline decreased. The mechanism by which L-carnitine a ffects mAb production and the metabolism of some amino acids is unknow n. This effect is likely to be indirect, since there was no net entry of L-[H-3]carnitine into the cells.