The muscarinic receptor subtype in mouse pancreatic B-cells

FEBS Lett. 1988 Aug 15;236(1):89-92. doi: 10.1016/0014-5793(88)80290-4.

Abstract

Isolated mouse islets were used to identify the muscarinic receptor subtype present in pancreatic B-cells. We thus compared the inhibitory potencies of atropine (non-specific), of pirenzepine (specific for M1 receptors) and of compound AF-DX 116 (specific for cardiac M2 receptors) on acetylcholine-induced insulin release, 86Rb+ efflux and 45Ca2+ efflux. The three antagonists inhibited all effects of acetylcholine, but EC50 values were markedly different: atropine = 1.5-5 nM, pirenzepine = 0.6-1.7 microM and AF-DX 116 = 1.7-11 microM. The results did not suggest that the various effects of ACh could result from the activation of different subtypes of receptors. It is concluded that muscarinic receptors of pancreatic B-cells belong to an M2 subtype distinct from the cardiac M2 receptors.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / metabolism
  • Animals
  • Atropine / pharmacology*
  • Calcium / metabolism
  • Female
  • Insulin / metabolism
  • Insulin Secretion
  • Islets of Langerhans / drug effects
  • Islets of Langerhans / metabolism*
  • Mice
  • Pirenzepine / analogs & derivatives*
  • Pirenzepine / pharmacology*
  • Potassium / metabolism
  • Receptors, Muscarinic / analysis*
  • Receptors, Muscarinic / drug effects
  • Rubidium Radioisotopes

Substances

  • Insulin
  • Receptors, Muscarinic
  • Rubidium Radioisotopes
  • Pirenzepine
  • Atropine
  • Acetylcholine
  • otenzepad
  • Potassium
  • Calcium