 |
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|
|
|
|
|
|
|
|
|
|
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Junctional-PM
complex is critical
|
|
|
for SMC
contraction/relaxation
|
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|
Rabbit IVC:
|
|
-adrenergic stimulation, Ca2+ is transiently
|
|
released from
radial SR through IP3R, near the
|
|
|
calmodulins
tethered to myofilaments
|
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|
Depletion of Ca2+
from SR/ER, which may be
|
|
augmented by
mitochondrial uptake causes
|
|
|
opening of
store-operated channels in the PM-
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|
|
SR; Na+
enters depolarizing membranes to
|
|
activate VGCC and
drives NCX in reverse
|
|
|
direction to
supply extracellular Ca2+ to PM-SR
|
junctional
space, which is taken up by
|
|
SERCA. As SR is refilled, IP3R are activated,
|
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|
to start the next
wave of regenerative Ca2+
|
|
release.
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|
