Peripheral inflammatory injury alters the relative abundance of G? subunits in the dorsal horn of the spinal cord and in the rostral ventromedial medulla of male rats.

ABSTRACT: A diverse array of G protein-coupled receptors (GPCRs) is implicated in the modulation of nociception. The efficacy and potency of several GPCR agonists change as a consequence of peripheral inflammatory injury. Whether these changes reflect alterations in expression of the G proteins themselves is not known. This study examined the expression of transcripts and proteins for the ? subunits of three classes of heteromeric G proteins in the dorsal horn of the spinal cord and the rostral ventromedial medulla (RVM) of male rats four days and two weeks after intraplantar injection of complete Freund’s adjuvant (CFA) or saline. Levels of G? transcript in the dorsal horn or RVM were unchanged by CFA treatment. However, in the dorsal horn, G?i protein decreased in cytosolic and membrane fractions four days after CFA treatment. Levels of G?z protein decreased in the membrane fraction. Levels of the other G? subunits did not differ. Levels of the G? subunits were unchanged two weeks after CFA treatment. In the RVM, G?z protein levels decreased in the cytosolic fraction four days after CFA treatment. No other differences were observed. Two weeks after CFA, the levels for all G? subunits trended higher in the RVM. These data indicate that peripheral inflammatory injury induces subtle changes in the abundance of G? subunits that is specific with respect to class, subcellular compartment, tissue, and time after injury. These changes have the potential to alter the balance of the different subcellular signaling pathways through which GPCR agonists act to modulate nociception.

SUBMITTER: Wattiez AS 

PROVIDER: S-EPMC5486491 | biostudies-literature | 2017 Jan-Dec

REPOSITORIES: biostudies-literature