Temperature-dependent vitellogenin-mRNA expression in primary cultures of rainbow trout (Oncorhynchus mykiss) hepatocytes at 14 and 18 degrees C

In order to study the influence of temperature on vitellogenin gene and est rogen receptor gene expression in primary hepatocytes from rainbow trout (O ncorhynchus mykiss), cells were exposed to 17 beta -estradiol, bisphenol-A and nonylphenol for 48 and 96 hr. Induction of vitellogenin-mRNA expression was detected in a non-radioactive dot blot/RNAse protection assay and by R T-PCR. In the dot blot/RNAse protection assay, the estrogenic potentials of bisphenol-A and nonylphenol were about 10(4)- to 10(5)-fold and 10(5)-fold lower than that of 17 beta -estradiol, respectively. The relative estrogen ic potential did not show any difference between 14 and 18 degreesC. In con trast, at 18 degreesC, RT-PCR analysis revealed increased amounts of vitell ogenin- and estrogen receptor-mRNA after 12 and 24 hr of exposure to 17 bet a -estradiol, if compared to 14 degreesC. Owing to increased vitellogenin g ene expression at 18 degreesC, the sensitivity of primary hepatocytes to 17 beta -estradiol and bisphenol-A could be increased. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.