Strain and species effects on the inhibition of hepatocyte intercellular communication by liver tumor promoters

Abstract

The effect of the liver tumor promoters phenobarbital (PB), 1,1-bis(4-chlorophenyl)-2,2,2-trichlorethane (DDT), and dieldrin on gap junction-mediated intercellular communication between primary cultured hepatocytes from male mice (B 6C 3F 1), C3H, C57BL, and Balb c strains) and male F344 rats was determined. Intercellular communication was detected autoradiographically as the passage and incorporation of [5- 3H]uridine nucleotides from prelabelled donor hepatocytes to donor-contacting recipient hepatocytes. At non-toxic concentrations, PB (20–500 μg/ml) inhibited intercellular communication between B 6C 3F 1, C3H, and Balb c mouse hepatocytes and F344 rat hepatocytes, but not between C57BL mouse hepatocytes. DDT (1–10 μg/ml) inhibited intercellular communication between hepatocytes from all 4 strains of mice and the F344 rat. Dieldrin (1–10 μg/ml) inhibited intercellular communication between hepatocytes from the 4 strains of mice but not between rat hepatocytes. These findings showed a good correlation with the in vivo liver tumor promoting/hepatocarcinogenic actions of PB, DDT and dieldrin in the 4 mouse strains and the F344 rat strain.