Multiple neuropeptides mobilise calcium in small cell lung cancer: effects of vasopressin, bradykinin, cholecystokinin, galanin and neurotensin.

The neuropeptides vasopressin, bradykinin, cholecystokinin, galanin, neurotensin and gastrin-releasing peptide stimulate rapid, transient increases in cytosolic Ca2+ in small cell lung cancer cell lines at nanomolar concentrations. Responsiveness to individual peptides is heterogeneous among the diverse cell lines, but the ability to respond to regulatory peptides is a general phenomenon. Peptide responses demonstrate homologous desensitisation and are blocked by ligand-specific antagonists, indicating that they are mediated by distinct receptors. Many neuropeptides are also secreted by small cell lung cancer. Here we suggest that multiple autocrine and paracrine interactions regulate its growth.