Immunohistochemistry of the Vasopressin Receptor AVPR V2 in Rat Brain

Abstract

Vasopressin hormone, found in most mammals, plays a key role in the homeostasis of water and solute concentration in the blood.  There are three known subtypes of vasopressin receptors, each with unique tissue distributions.  Arginine vasopressin receptor 2 (AVPR V2) has been identified in mammals in the kidney, lung, and various regions of the brain.  Binding of vasopressin to the AVPR V2 receptor has been associated with antidiuresis and decreased cardiac output as well as various social behaviors in several mammal species.  The purpose of this study was to determine whether the AVPR V2 receptor is present in rat brain, and if present, to identify the specific brain region and cell type expressing the receptor.  Frozen, preserved rat brain was sectioned on a cryostat and processed with rabbit polyclonal AVPR V2 and biotinylated goat polyclonal secondary antibody to rabbit IgG.  Staining of antibody treated sections revealed AVPR V2 receptors were present on Purkinje cell axons and cells bodies in the cerebellum.  These data suggest that the cerebellum of rats may be an important regulatory site of vasopressin functions.