It is generally believed that the activation of various cell surface receptors results in the phospholipase C-catalyzed production of inositol trisphosphate which, in turn, increases the intracellular concentration of free Ca2+ by stimulating its release from non-mitochondrial sources. We have investigated both the production of inositol trisphosphate and changes in intracellular Ca2+ concentration in rat pancreatic acini in response to caerulein and CCK-JMV-180, two analogs of cholecystokinin. Both of these analogs cause comparable increases in the rate of amylase secretion and in intracellular Ca2+ concentration but their effects on inositol phosphate generation are dramatically different; caerulein stimulates significant production of inositol phosphates within 1 min of its addition, whereas no detectable levels of inositol phosphates were generated within the same time after addition of CCK-JMV-180. These results suggest that the CCK-JMV-180 stimulated release of intracellular Ca2+ is not mediated by inositol trisphosphate but some other as yet unidentified messenger.
|Original language||English (US)|
|Number of pages||6|
|Journal||Biochemical and biophysical research communications|
|State||Published - Oct 16 1989|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology