This study provides further information on the central expression of GR in a teleost species and demonstrates that the main neuronal populations involved in the regulation of GTH-2 secretion are likely to be regulated by cortisol in rainbow trout. In addition, we show that both GTH-1 and GTH-2 cells strongly express rtGR. Although the precise molecular targets of cortisol in these different cell populations are presently unknown, these results open new avenues for future investigations. ampicillin antibiotic
Similar to what was already reported for the antibodies raised in rabbit, those obtained in guinea pigs allowed the identification, by Western blotting, of two protein species of 100 and 104 kDa in COS-1 cells transfected with the rtGR cDNA. The sizes of these denaturated proteins are larger than the expected value of 83 kDa deduced from the amino acid sequence of the cloned rtGR cDNA. The difference can be explained by the important posttransla-tional maturation of the proteins such as phosphorylation and/or glycosylation as already described for other nuclear receptors. The guinea pig antibodies resulted in an excellent background/staining ratio and revealed an overall pattern of distribution similar to that previously reported with the rabbit antibodies.