Presence of beta-arrestin-1 immunoreactivity in the cutaneous nerve fibers of rat glabrous skin.

beta-Arrestin-1 (betaArr1) plays a major role in the desensitization and internalization of G protein-coupled receptors. We previously localized betaArr1 in the sensory neurons of rat lumbar 4 and 5 dorsal root ganglia (DRG) and reported the predominant presence of betaArr1 in the small-diameter DRG neurons that are often implicated with nociception. Because of betaArr1's crucial role in regulating the initiation of cellular signaling, in the current study we evaluated the distribution of betaArr1 in the peripheral sensory terminals where various receptors are present. Western blotting confirmed the presence of betaArr1 immunoreactivity in the rat skin. Sciatic nerve ligation demonstrated that betaArr1 is transported peripherally from the DRG, and immunohistochemistry showed betaArr1 immunoreactivity in the glabrous skin of the rat hindpaw. In the glabrous skin, strong betaArr1 immunoreactivity was detected in nerve fibers in the dermal nerve plexus and dermal papillae. Fine varicose immunoreactive fibers were found in the epidermis. In addition, betaArr1 was observed in specialized sensory receptors such as Meissner corpuscles. Our observations thus indicate that betaArr1 may be involved in modulation of specific tactile stimulation from the skin in addition to nociception.