A SOMATOSTATIN RECEPTOR 1 SELECTIVE LIGAND INHIBITS CA2-1046-38 CELLS( CURRENTS IN RAT INSULINOMA)

Rat insulinoma 1046-38 cells represent a model system to study beta-ce ll function, The mRNAs for sst1 and sst2, two of the five somatostatin receptors, were detected by reverse transcription polymerase chain re action amplification in these cells. Displacement binding analysis sug gested that sst1 represents the major somatostatin receptor subtype. T he sst1 selective compound CH-275 did not inhibit adenylyl cyclases wh ile compounds that activated sst2 did, In contrast, CH-275 caused a ma rked inhibition of voltage-operated Ca2+ channels while the sst2 speci fic analog octreotide elicited a less pronounced effect suggesting tha t in rat insulinoma 1046-38 cells sst1 preferably mediates the inhibit ion of Ca2+ channels. (C) 1998 Federation of European Biochemical Soci eties.