Changes in IP3receptor are associated with altered calcium response to cholecystokinin in diabetic rat pancreatic acini

Gyeong Ryul Ryu, Choon Ho Sung, Myung Jun Kim, Jong Ho Sung, Kweon Haeng Lee, Dong Won Park, Sang Soo Sim, Do Sik Min, Duck Joo Rhie, Shin Hee Yoon, Sang June Hahn, Myung Suk Kim, Yang Hyeok Jo

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Abstract

Objectives: Pancreatic acini of diabetic rats release amylase less than normal acini on cholecystokinin (CCK) stimulation. Pancreatic enzyme secretion by CCK is closely related to the second messenger inositol 1,4,5-trisphosphate (IP3), which mobilizes intracellular calcium stores via the endoplasmic reticulum-located receptor IP3(IP3R). Recently, we observed altered intracellular calcium response on CCK-8 stimulation in streptozotocin (STZ)- treated diabetic rat acini. Methods: To determine whether IP3R is involved in altered calcium response, we measured inositol phosphate (IP) formation and the expression and phosphorylation of type III IP3R protein in diabetic acini. Also, CCK receptor mRNA expression was examined to determine whether the changes in IP formation and IP3R protein phosphorylation in diabetic acini might result from the defect at the postreceptor level. Results: CCK-8-induced IP formation at all concentrations used was significantly reduced in diabetic acini, though IP formation was increased in a concentration-dependent manner. The expression of type III IP3R protein was significantly reduced in diabetic acini. Additionally, CCK-8-stimulated phosphorylation of type III IP3R protein was not observed in diabetic acini. However, the reduction of CCK receptor mRNA expression was not detected in diabetic acini. Conclusion: Our results indicate that altered calcium response to CCK-8 in diabetic acini might be associated with a post-CCK receptor defect including the changes in IP formation, type III IP3R protein expression, and phosphorylation of type III IP3R protein.

Original languageEnglish
Pages (from-to)e106-e112
JournalPancreas
Volume29
Issue number4
DOIs
Publication statusPublished - 2004 Nov

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All Science Journal Classification (ASJC) codes

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism
  • Hepatology
  • Endocrinology

Cite this

Ryu, G. R., Sung, C. H., Kim, M. J., Sung, J. H., Lee, K. H., Park, D. W., Sim, S. S., Min, D. S., Rhie, D. J., Yoon, S. H., Hahn, S. J., Kim, M. S., & Jo, Y. H. (2004). Changes in IP3receptor are associated with altered calcium response to cholecystokinin in diabetic rat pancreatic acini. Pancreas, 29(4), e106-e112. https://doi.org/10.1097/00006676-200411000-00164