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 17 beta-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, ER alpha and ER beta indicate that 100% colocalization of ER alpha with OB-R and about 15% colocalization of ER beta 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 ER alpha-dependent way.