Detection and estrogen regulation of leptin receptor expression in rat dorsal root ganglion.

Leptin receptor (OB-R) is a polypeptide consisting of a single transmembrane-spanning component. OB-R widely distributes in various tissues, including the peripheral nervous system (PNS). However, there is no data about the expression of OB-R in the dorsal root ganglion (DRG). In the present study, we first detected the expressions of OB-R protein and mRNA in the rat DRG using the methods of immunohistochemistry, western blot and reverse transcriptase polymerase chain reaction (RT-PCR). Estrogen is known to influence different functions on the DRG. In this study, we observed that 17beta-estradiol (E(2)) can increase the expressions of OB-R protein and mRNA (P<0.05) in ovariectomized rat DRG and these actions can be prevented by tamoxifen which is a specific estrogen receptors (ERs) antagonist. In addition, the results of dual labeling of OB-R with the two ER isoforms, ERalpha and ERbeta indicate that 100% colocalization of ERalpha with OB-R and about 15% colocalization of ERbeta with OB-R in DRG neurons. These results indicate that OB-R is expressed in the rat DRG and E(2) may up-regulate the expression of the OB-R protein and mRNA in an ERalpha-dependent way.