Differential distribution of alternatively spliced somatostatin receptor 2isoforms (sst(2A) and sst(2B)) in rat spinal cord

We have recently shown that the cytoplasmic tail of the somatostatin recept or sst(2) undergoes alternative splicing giving rise to two isoforms, sst(2 A) and sst(2B) In the present study, we have raised polyclonal antibodies t hat specifically detect either sst(2A) or sst(2B) and used these antisera f or immunocytochemical localization of the receptor proteins in the rat spin al cord. sst(2A)-immunoreactivity formed a dense network consisting of neur onal perikarya and dendrites in the superficial layers of the dorsal horn. In contrast, prominent sst(2A)-immunoreactivity was found on neuronal perik arya and proximal dendrites throughout the gray matter of the spinal cord. Taken together, we show that alternative carboxy-terminal splicing is invol ved in cell-specific expression of somatostatin receptor sst(2) isoforms in rat spinal cord, and that sst(2A) and sst(2B) mediate effects of somatosta tin at different cellular sites. (C) 1998 Published by Elsevier Science Ire land Ltd. All rights reserved.