Induction of chromosomal aberrations and SCE by chloramphenicol

The induction of chromosomal aberrations and sister-chromatid exchanges (SCE) was studied in human lymphocyte cultures treated with chloramphenicol (CAP), an antimicrobial agent acting by inhibiting protein synthesis. Moreover chromosomal aberrations and sister-chromatid exchanges were studied in bone marrow cells of treated mice and in Chinese hamster cell cultures (V79) respectively. While no aberrations were induced by short treatments in human lymphocytes exposed in G1 and G2 phases, high frequencies of aberrations, exclusively of the chromatid type, were induced when the drug was administered during a whole cell cycle. Aberrant metaphases were detected only at the end and a few hours after the end of treatment; at later times aberrant cells reached control values. Doses producing aberrations only slightly increased SCE both in human lymphocytes and in V79 cells. In mouse bone marrow cells CAP induced a high mitotic delay and few structural aberrations; intrachromosomal vacuoles were observed.