Somatostatin and octreotide interfere with calcium signalling in pancreatic beta-cells but not in normal and pathological parathyroid cells.

Somatostatin and its analogue octreotide exert antisecretory actions in several endocrine tissues. Somatostatin and octreotide (100 nM) promptly and reversibly counteracted glucose stimulated elevations of the concentration of cytoplasmic Ca2+ ([Ca2+]i) in mouse pancreatic beta-cells. In contrast both somatostatin and octreotide failed to affect basal or high Ca2+ stimulated [Ca2+]i of normal bovine, and adenomatous or hyperplastic human parathyroid cells. Furthermore, PTH release of these cells was unaltered by 1-1000 nM somatostatin and octreotide. The results indicate that somatostatin and octreotide lack direct actions on parathyroid cells, which contrasts to their effects on calcium signalling in cells from pancreatic islets.