Complementary expression of SN1 and SAT2 in the islets of Langerhans suggests concerted action of glutamine transport in the regulation of insulin secretion

Biochem Biophys Res Commun. 2009 Apr 10;381(3):378-82. doi: 10.1016/j.bbrc.2009.02.062. Epub 2009 Feb 20.


Insulin and glucagon secretion from the islets of Langerhans is highly regulated. Although an increased plasma glucose level is the major stimulus for insulin exocytosis, roles for glutamine and glutamate have been suggested. Interestingly, the islet cells display elements associated with synaptic transmission. In the central nervous system (CNS), glutamine transport by SN1 and SAT2 sustain the generation of neurotransmitter glutamate. We hypothesized that the same transporters are essential for glutamine transport into the islet cells and for subsequent formation of glutamate acting as an intracellular signaling molecule. We demonstrate that islet cells express several transporters which can mediate glutamine transport. In particular, we show pronounced expression of SN1 and SAT2 in B-cells and A-cells, respectively. The cell-specific expression of these transporters together with their functional characteristics suggest an important role for glutamine in the regulation of insulin secretion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyltransferases / biosynthesis*
  • Acetyltransferases / genetics
  • Amino Acid Transport Systems, Neutral / biosynthesis*
  • Amino Acid Transport Systems, Neutral / genetics
  • Animals
  • Biological Transport
  • Glucagon-Secreting Cells / metabolism*
  • Glutamine / metabolism*
  • Insulin / metabolism*
  • Insulin Secretion
  • Insulin-Secreting Cells / metabolism*
  • Mice
  • Rats
  • Rats, Wistar


  • Amino Acid Transport Systems, Neutral
  • Insulin
  • system N protein 1
  • Glutamine
  • Acetyltransferases
  • diamine N-acetyltransferase