Functional properties of ryanodine receptors from rat dorsal root ganglia.
The properties of ryanodine receptors (RyRs) from rat dorsal root ganglia (DRGs) have been studied. The density of RyRs (Bmax) determined by [3H]ryanodine binding was 63 fmol/mg protein with a dissociation constant (Kd) of 1.5 nM. [3H]Ryanodine binding increased with caffeine, decreased with ruthenium red and tetracaine, and was insensitive to millimolar concentrations of Mg2+ or Ca2+. DRG RyRs reconstituted in planar lipid bilayers were Ca2+-dependent and displayed the classical long-lived subconductance state in response to ryanodine; however, unlike cardiac and skeletal RyRs, they lacked Ca2+-dependent inactivation. Antibodies against RyR3, but not against RyR1 or RyR2, detected DRG RyRs. Thus, DRG RyRs are immunologically related to RyR3, but their lack of divalent cation inhibition is unique among RyR subtypes.
Lokuta
Andrew J
AJ
Department of Physiology, University of Wisconsin Medical School, Madison, WI 53706, USA. ajlokuta@facstaff.wisc.edu
Komai
Hirochika
H
McDowell
Thomas S
TS
Valdivia
Héctor H
HH
D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002645:Chickens; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D012433:Ryanodine / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D013552:Swine
D008051:Lipid Bilayers; D019837:Ryanodine Receptor Calcium Release Channel; D012433:Ryanodine; D002118:Calcium