The Effect of Peroxisome Proliferators on S-Phase Synthesis in Primary Cultures of Fish Hepatocytes

The ability of seven structurally diverse peroxisome proliferators to induce S-phase synthesis was studied in primary cultures of rainbow trout and medaka hepatocytes. Cells were maintained in serum-free conditions designed to facilitate attachment, viability, and function. Lead nitrate, a well-known and potent rodent liver mitogen, was used in vitro in trout and medaka and in vivo in trout to evaluate the capacity of the species and our system to respond to mitogenic stimuli. S-phase synthesis induced by peroxosome proliferators did not result in any statistically significant increase over control cultures. These in vitro results are supported by in vivo data previously obtained and the present work with lead nitrate.