Table 1. Neuropeptide Ca2+ mobilisation in the SCLC GLC longitudinal cell line series.
| Ca2+ mobilising neuropeptides | GLC14 | GLC16 | GLC19 |
|---|---|---|---|
| Bombesin | 6±3 (n=7) | 25±5 9 (n=7) | 100±15 (n=7) |
| Bradykinin | 66±8 (n=8) | 105±7 (n=8) | 98±12 (n=10) |
| Carbamylcholine | 83±11 (n=3) | 104±18 (n=5) | 113±25 (n=7) |
| Cholecystokinin | 31±9 (n=4) | 32±4 (n=3) | 56±5 (n=4) |
| Neuromedin B | 7±4 (n=4) | 25±3 (n=3) | 150±20 (n=4) |
| Neurotensin | — (n=3) | — (n=3) | 43±12 (n=5) |
| Substance P | — (n=3) | 39±6 (n=3) | 72±10 (n=3) |
| Vasopressin | — (n=3) | 28±8 (n=7) | 42±9 (n=7) |
| Serum | 105±8 (n=8) | 109±15 (n=8) | 119±19 (n=10) |
The GLC19, 16 and 14 SCLC cell lines were loaded with 1 μM Fura2AME washed and resuspended in 2 ml electrolyte solution and the cell suspension placed in a quartz cuvette and stirred continuously. Neuropeptides were added at 100 nM concentration and fluorescence was recorded continuously as described in Materials and Methods. Results are expressed as change in intracellular calcium (nM). The following peptides were also tested at 100 nM–1 μM concentrations and no increase in [Ca2+]i was ever observed: adrenocorticotrophin hormone, angiotensin 1, atrial natriuretic peptide, calcitonin, chorionic gonadotropin, dynorphin, β-endorphin, endothelin, epinephrine, galanin, growth hormone-releasing hormone, gastric-inhibitory peptide, glucagons 5-hydroxytryptamine, Leu-enkephalin, neuropeptide-Y, parathyroid hormone, substance K, thyrotrophin-releasing hormone.