Regulation of ATP-sensitive K sup + channels in insulinoma cells: Activation by somatostatin and protein kinase C and the role of cAMP

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.8.2971· OSTI ID:5300376

De Weille, J R; Schmid-Antomarchi, H; Fosset, M; Lazdunski, M ^[1]

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1. Centre de Biochimie du Centre National de la Recherche Scientifique, Nice (France)

The actions of somatostatin and of the phorbol ester 4{beta}-phorbol 12-myristate 13-acetate (PMA) were studied in rat insulinoma (RINm5F) cells by electrophysiological and {sup 86}Rb{sup +} flux techniques. Both PMA and somatostatin hyperpolarize insulinoma cells by activating ATP-sensitive K{sup +} channels. The presence of intracellular GTP is required for the somatostatin effects. PMA- and somatostatin-induced hyperpolarization and channel activity are inhibited by the sulfonylurea glibenclamide. Glibenclamide-sensitive {sup 86}Rb{sup +} efflux from insulinoma cells is stimulated by somatostatin in a dose-dependent manner (half maximal effect at 0.7 nM) and abolished by pertussis toxin pretreatment. Mutual roles of a GTP-binding protein, of protein kinase C, and of cAMP in the regulation of ATP-sensitive K{sup +} channels are discussed.

• OSTI ID: 5300376
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 86:8; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
MEMBRANE TRANSPORT
PHYSIOLOGY
PHORBOL ESTERS
BIOLOGICAL EFFECTS
RUBIDIUM 86
UPTAKE
SOMATOSTATIN
AMP
ATP
PHOSPHOTRANSFERASES
POTASSIUM COMPOUNDS
RATS
TUMOR CELLS
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARCINOGENS
DAYS LIVING RADIOISOTOPES
ENZYMES
ESTERS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MINUTES LIVING RADIOISOTOPES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
RADIOISOTOPES
RODENTS
RUBIDIUM ISOTOPES
TRANSFERASES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques