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Glucose‐induced electrical activity in pancreatic islet cells
Author(s) -
Dean P. M.,
Matthews E. K.
Publication year - 1970
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1970.sp009207
Subject(s) - islet , membrane potential , chemistry , medicine , endocrinology , pancreatic islets , biophysics , depolarization , secretion , intracellular , insulin , biology , biochemistry
1. Intracellular recording of the transmembrane potential in mouse pancreatic cells revealed a membrane potential of −20·1 ± 0·8 mV for islet cells and −41·2 ± 1·4 mV for acinar cells. 2. The membrane potential of islet cells was glucose dependent and in the absence of glucose the cells hyperpolarized to −32·7 mV; with glucose 27·7 m M they depolarized to −16·1 mV. 3. Above a threshold concentration of glucose (4 m M ) small action potentials of amplitude 1‐4 mV were induced in islet cells. The percentage of cells impaled exhibiting action potentials reached a maximum of 80% at 27·7 m M glucose. 4. Mannose 16·6 m M was similar to glucose in its ability to induce action potential discharge in islet cells. 5. 2,4‐Dinitrophenol (0·25 m M ) hyperpolarized islet cells and blocked electrical activity induced by glucose 11·1 m M . 6. Adrenaline (1 μ M ) completely blocked glucose‐induced electrical activity but without altering the membrane potential. 7. The origin and functional significance of glucose‐induced electrical activity in islet cells is discussed in relation to insulin secretion.