These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Pancreatic hormone receptors on islet cells.
    Author: Van Schravendijk CF, Foriers A, Hooghe-Peters EL, Rogiers V, De Meyts P, Sodoyez JC, Pipeleers DG.
    Journal: Endocrinology; 1985 Sep; 117(3):841-8. PubMed ID: 2990873.
    Abstract:
    To assess whether islet cells are equipped with recognition units which allow an intra-islet regulation via released hormones, the presence of insulin and glucagon receptors is investigated on purified pancreatic A and B cells. Mono-[125I]glucagon is shown to bind specifically to islet B cells, with similar binding characteristics as in isolated hepatocytes but involving less receptors per cell (2.10(4) per B cell vs. 8.10(5) per liver cell). Binding is half-maximally displaced by 5.10(-9) M glucagon, a concentration known to induce half-maximal biological effects in isolated B cells. These results are compatible with a regulatory role of glucagon in the insulin release process. No specific binding of [125I]tyr-A14-insulin is detected on pancreatic A cells. In order to increase receptor assay sensitivity, [123I]tyr-A14-insulin is prepared with at least 5-fold higher specific activity. Its validity for in vitro receptor analysis is demonstrated in IM-9 lymphocytes, where insulin binding is detectable down to 10(4) cells/ml. However, no insulin-binding sites are identified on pancreatic A cells, even at 10(6) cells/ml. If isolated A cells contain high affinity insulin receptors, their number should be inferior to 400 per cell, which is 50- to 500-fold lower than in classical insulin target cells. These findings explain the insensitivity of the glucagon release process to acute exposure to insulin.
    [Abstract] [Full Text] [Related] [New Search]