Quantitation of ryanodine receptor of rabbit skeletal muscle, heart and brain.
The total number of high-affinity ryanodine receptor (RyR) binding sites present in skeletal and cardiac muscle and in brain tissue of the rabbit was determined by [3H]ryanodine binding to subfractions obtained by differential centrifugation of homogenates prepared in a low-ionic strength medium, containing 0.5% Chaps. In all three tissues at least 80% of [3H]ryanodine binding was recovered in the total membrane (TM) fraction obtained by centrifuging between 650 g for 10 min and 120,000 x g for 90 min. Skeletal muscle displayed higher contents of high-affinity RyR sites (about 49 pmol/g wet wt) than heart and brain (about 12 pmol and 3.5 pmol/g wet wt, respectively). The affinity for ryanodine, as well as the affinity for Ca2+, in the absence or presence of Ca2(+)-releasing drugs (caffeine and doxorubicin) of TM from skeletal muscle, were found to be identical to those of purified terminal cisternae. As low as 1 g of tissue was sufficient to perform several experiments.
Damiani
E
E
Centro di Studio per la Biologia e la Fisiopatologia muscolare, Università di Padova, Italy.
Tobaldin
G
G
Volpe
P
P
Margreth
A
A
D000818:Animals; D001921:Brain / Q000378:metabolism*; D007700:Kinetics; D009132:Muscles / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D009210:Myofibrils / Q000378:metabolism; D011817:Rabbits; D011950:Receptors, Cholinergic / Q000302:isolation & purification / Q000378:metabolism*; D012433:Ryanodine / Q000378:metabolism*; D019837:Ryanodine Receptor Calcium Release Channel; D012519:Sarcoplasmic Reticulum / Q000378:metabolism
D011950:Receptors, Cholinergic; D019837:Ryanodine Receptor Calcium Release Channel; D012433:Ryanodine