Ca2+ channel gating Flashcards
what is the role of L-type ca2+ channels in the CVS
maintains the platue phase of the ventricle AP
generates depolariation phase of AP in the SA and AV
generates the major component of ca2+ influ needed for calcium induced caluim relase
important entry route for Ca2+ in smooth muscle(contaction)
how many subunits make up the l-type ca2+ channel
3 subunits a, a2delta and beta
what does the a subunit of l-type ca2+ channels contribute to its activity?
Ca2+ dependent incativation due to the c terminal having the clamodulin binfing site
and VDI as it has the i-ii loop on between transmembrane regoin 1 and 2
what does the a2 delta subunit contribute of L-type ca2+ channels to its activity?
voltage dependednt activation
what does the beta subunit contribute to the activity of l-type ca2+ channels?
regualtes VDI and CDI
what us Cs good for
blocking K+ channels
what is Cd2+ good for?
blocking Ca2+ channels
how can we isoplate ca2+ currents
pre pulse will cause the inactivation of Na+ channels but most of ca2+ channels will still be avalibale
what does forskolin do?
actiavtes AC
what does H-89 do?
inhibits PKA
what happens to I Ca2+ with more activated PKA
the current is larger
what gives the window current
the cross over of avalibity and activation curves
what does amphotericin do?
perforates plasma membrane so inly monovalent ions can pass through.
what is special about ba2+ ions
pass through ca2+ channels batter thann ca2+| aloso no ca2+ incativateion
