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. 1991 May;10(5):1275-84.
doi: 10.1002/j.1460-2075.1991.tb08069.x.

GABA and pancreatic beta-cells: colocalization of glutamic acid decarboxylase (GAD) and GABA with synaptic-like microvesicles suggests their role in GABA storage and secretion

A Reetz  1 , M Solimena, M Matteoli, F Folli, K Takei, P De Camilli
Affiliations

GABA and pancreatic beta-cells: colocalization of glutamic acid decarboxylase (GAD) and GABA with synaptic-like microvesicles suggests their role in GABA storage and secretion

A Reetz et al. EMBO J. 1991 May.

Abstract

GABA, a major inhibitory neurotransmitter of the brain, is also present at high concentration in pancreatic islets. Current evidence suggests that within islets GABA is secreted from beta-cells and regulates the function of mantle cells (alpha- and delta-cells). In the nervous system GABA is stored in, and secreted from, synaptic vesicles. The mechanism of GABA secretion from beta-cells remains to be elucidated. Recently the existence of synaptic-like microvesicles has been demonstrated in some peptide-secreting endocrine cells. The function of these vesicles is so far unknown. The proposed paracrine action of GABA in pancreatic islets makes beta-cells a useful model system to explore the possibility that synaptic-like microvesicles, like synaptic vesicles, are involved in the storage and release of non-peptide neurotransmitters. We report here the presence of synaptic-like microvesicles in beta-cells and in beta-cells. Some beta-cells in culture were found to extend neurite-like processes. When these were present, synaptic-like microvesicles were particularly concentrated in their distal portions. The GABA synthesizing enzyme, glutamic acid decarboxylase (GAD), was found to be localized around synaptic-like microvesicles. This was similar to the localization of GAD around synaptic vesicles in GABA-secreting neurons. GABA immunoreactivity was found to be concentrated in regions of beta-cells which were enriched in synaptic-like microvesicles. These findings suggest that in beta-cells synaptic-like microvesicles are storage organelles for GABA and support the hypothesis that storage of non-peptide signal molecules destined for secretion might be a general feature of synaptic-like microvesicles of endocrine cells.

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References

    1. Diabetes. 1990 Apr;39(4):406-14 - PubMed
    1. Ann N Y Acad Sci. 1987;493:461-79 - PubMed
    1. J Neurochem. 1990 Feb;54(2):363-72 - PubMed
    1. Proc Natl Acad Sci U S A. 1990 Mar;87(5):1988-92 - PubMed
    1. J Cell Biol. 1987 Apr;104(4):1047-57 - PubMed

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