A third type of calcium current in cultured human skeletal muscle cells.
A third type of calcium current could be recorded on a non-negligible number of human skeletal muscle cells (normal and Duchenne dystrophic (DMD)) in primary culture. This transient current exhibited a maximum at 0 mV, a time-to-peak around 30 ms, an inactivation time constant around 70 ms and was insensitive to nifedipine. On these basis, it differentiates from T- and L-type previously described and looks like the neuronal N-type. However, this third type of current was not sensitive to omega-Cgtx, a specific N-type blocker. The occurrence and the possible role of this current are briefly discussed.
Rivet
M
M
Laboratoire de Physiologie Générale, CNRS U.R.A. 290, Université de Poitiers, France.
Cognard
C
C
Imbert
N
N
Rideau
Y
Y
Duport
G
G
Raymond
G
G
D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D005682:Gadolinium / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008564:Membrane Potentials; D009132:Muscles / Q000502:physiology*; D009543:Nifedipine / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D013997:Time Factors; D020866:omega-Conotoxin GVIA
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010456:Peptides, Cyclic; D020866:omega-Conotoxin GVIA; D005682:Gadolinium; D009543:Nifedipine