9-Methyl-7-bromoeudistomin D induces Ca2+ release from cardiac sarcoplasmic reticulum.
9-Methyl-7-bromoeudistomin D (MBED), the most powerful caffeine-like releaser of Ca2+ from skeletal muscle sarcoplasmic reticulum, induced Ca2+ release from the cardiac sarcoplasmic reticulum. MBED (5 microM) and caffeine (1 mM) caused rapid Ca2+ release from the fragmented cardiac sarcoplasmic reticulum in a Ca2+ electrode experiment. [3H]MBED bound to a single class of high-affinity binding sites in cardiac sarcoplasmic reticulum membranes (Kd = 150 nM). These results suggest that MBED binds to a specific binding site on cardiac sarcoplasmic reticulum membranes to induce Ca2+ release from the cardiac sarcoplasmic reticulum. Thus, MBED is a useful probe for characterizing Ca2+ release the channels not only in skeletal sarcoplasmic reticulum but also in cardiac sarcoplasmic reticulum.
Seino-Umeda
A
A
Yokohama Research Center, Mitsubishi Chemical, Japan.
Fang
Y I
YI
Ishibashi
M
M
Kobayashi
J
J
Ohizumi
Y
Y
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002243:Carbolines / Q000493:pharmacokinetics / Q000494:pharmacology*; D004285:Dogs; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism*
D002243:Carbolines; C060741:9-methyl-7-bromoeudistomin D; D002118:Calcium