Dominant Role of N-Type Ca2+ Channels in Evoked Release of Norepinephrine from Sympathetic Neurons
LD Hirning, AP Fox, EW McCleskey, BM Olivera… - Science, 1988 - science.org
Science, 1988•science.org
Multiple types of calcium channels have been found in neurons, but uncertainty remains
about which ones are involved in stimulus-secretion coupling. Two types of calcium
channels in rat sympathetic neurons were described, and their relative importance in
controlling norepinephrine release was analyzed. N-type and L-type calcium channels
differed in voltage dependence, unitary barium conductance, and pharmacology.
Nitrendipine inhibited activity of L-type channels but not N-type channels. Potassium-evoked …
about which ones are involved in stimulus-secretion coupling. Two types of calcium
channels in rat sympathetic neurons were described, and their relative importance in
controlling norepinephrine release was analyzed. N-type and L-type calcium channels
differed in voltage dependence, unitary barium conductance, and pharmacology.
Nitrendipine inhibited activity of L-type channels but not N-type channels. Potassium-evoked …
Multiple types of calcium channels have been found in neurons, but uncertainty remains about which ones are involved in stimulus-secretion coupling. Two types of calcium channels in rat sympathetic neurons were described, and their relative importance in controlling norepinephrine release was analyzed. N-type and L-type calcium channels differed in voltage dependence, unitary barium conductance, and pharmacology. Nitrendipine inhibited activity of L-type channels but not N-type channels. Potassium-evoked norepinephrine release was markedly reduced by cadmium and the conesnail peptide toxin ω-Conus geographus toxin VIA, agents that block both N- and L-type channels, but was little affected by nitrendipine at concentrations that strongly reduce calcium influx, as measured by fura-2. Thus N-type calcium channels play a dominant role in the depolarization-evoked release of norepinephrine.
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