Effects of the nitric oxide synthase inhibitor N omega nitro-L-arginine methyl ester on electrical activity and ion channels of mouse pancreatic B cells.
The effects of the nitric oxide (NO) synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) were studied on electrical activity, K+ATP currents and voltage-dependent K+ and Ca2+ channel currents in mouse pancreatic B cells. In the presence of 15 mM glucose, L-NAME (> 5 mM) depolarized the B cell membrane and electrical activity became continuous. The depolarization caused by L-NAME was not reversed by the addition of a membrane permeant cyclic GMP analogue. L-NAME inhibited the whole-cell K+ATP current reversibly by reducing the single channel current conductance and open probability. The results are consistent with the assumption that L-NAME depolarizes the B cell membrane by a direct action on the K+ATP channel. L-NAME also influenced the whole-cell current through voltage-dependent K+ and Ca2+ channels.
Krippeit-Drews
P
P
Institute of Pharmacy, University of Tübingen, Germany.
Welker
S
S
Drews
G
G
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015220:Calcium Channels / Q000502:physiology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D005947:Glucose / Q000494:pharmacology; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D009991:Oscillometry; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*
D015220:Calcium Channels; D004791:Enzyme Inhibitors; D015221:Potassium Channels; C016276:8-bromocyclic GMP; D001120:Arginine; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP; D005947:Glucose; D019331:NG-Nitroarginine Methyl Ester