The muscarinic receptor subtype in mouse pancreatic B-cells
JC Henquin, M Nenquin - FEBS letters, 1988 - Elsevier
JC Henquin, M Nenquin
FEBS letters, 1988•ElsevierIsolated 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 M 1 receptors) and of compound AF-DX 116 (specific for cardiac M
2 receptors) on acetylcholine-induced insulin release, 86 Rb+ efflux and 45 Ca 2+ efflux.
The three antagonists inhibited all effects of acetylcholine, but EC 50 values were markedly
different: atropine= 1.5–5 nM, pirenzepine= 0.6–1.7 μM and AF-DX 116= 1.7–11 μM. The …
pancreatic B-cells. We thus compared the inhibitory potencies of atropine (non-specific), of
pirenzepine (specific for M 1 receptors) and of compound AF-DX 116 (specific for cardiac M
2 receptors) on acetylcholine-induced insulin release, 86 Rb+ efflux and 45 Ca 2+ efflux.
The three antagonists inhibited all effects of acetylcholine, but EC 50 values were markedly
different: atropine= 1.5–5 nM, pirenzepine= 0.6–1.7 μM and AF-DX 116= 1.7–11 μM. The …
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 μM and AF-DX 116 = 1.7–11 μM. 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.
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