ISSN:
1432-2013
Keywords:
CACA GABAC receptors Gastrointestinal neurotransmitters Hormone secretion Neuroendocrine tumor STC-1
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract. Although GABAC receptors play a crucial role in the mammalian central nervous system, their functional expression in peripheral tissues has not yet been studied. Using the gut neuroendocrine tumor cell line STC-1 as a model, we provide first evidence for the functional expression of GABAC receptors in the gut: mRNAs of the GABAC receptor subunits ρ1 and ρ2 were detected in STC-1 cells by reverse transcription polymerase chain reaction (RT-PCR). Applying anti-ρ-antibodies, specific immunostaining for GABAC receptors was observed. For functional characterization, the effects of GABAC receptor activation on [Ca2+]i and hormone secretion were studied. The selective GABAC receptor agonist cis-4-aminocrotonic acid (CACA) induced dose-dependent increases both of [Ca2+]i and of hormone (cholecystokinin) secretion. The stimulatory effects of CACA were antagonized by the GABAC receptor blockers (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid (TPMPA) and 3-aminopropyl(methyl)phosphinic acid (3-APMPA). These results demonstrate that GABAC receptors play an important role in neuroendocrine gastrointestinal secretion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004240000412
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