Signal transduction by membrane receptors in viable electropermeabilized cells: isoproterenol-stimulated cyclic AMP synthesis in C6 glioma cells.
The activity of beta-adrenergic receptors at the plasma membrane level was investigated in viable, electropermeabilized C6 glioma cells. Electric field pulses were applied directly to the plated cells without any previous proteinase treatment. The affinity for isoproterenol and the density of the beta-adrenergic receptors, as judged from the number of [3H]CGP-12177 binding sites, were not affected by the electropermeabilization whereas the isoproterenol-stimulated cAMP accumulation was transiently impaired. This decrease in activity is due to an electropermeabilization-induced GTP leak. Normal activity could be obtained either by treating the cells by the electric field in a GTP-containing buffer, or by spontaneous recovery of the cells after the resealing of the plasma membrane, with a delay depending on the temperature. The activity of the receptors was not affected by the structural organization of the membrane associated to its electropermeabilization.
Volker
T T
TT
Institut de Biochimie Cellulaire et de Neurochimie, Centre National de la Recherche Scientifique et Université de Bordeaux II, France.
Pianet
I
I
Labouesse
J
J
Teissié
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism; D000319:Adrenergic beta-Antagonists / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D002467:Cell Nucleus / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis*; D004558:Electric Stimulation; D005910:Glioma; D006160:Guanosine Triphosphate / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology*; D007700:Kinetics; D011412:Propanolamines / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011943:Receptors, Adrenergic, beta; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D007545:Isoproterenol; C033394:CGP 12177