BisG10, a K+ channel blocker, affects the calcium release channel from skeletal muscle sarcoplasmic reticulum.
The action of bisG10, a potent K+ channel inhibitor, was tested on the Ca2+ release from isolated sarcoplasmic reticulum vesicles of rabbit skeletal muscle. Using a rapid filtration technique, we found that the drug inhibited Ca(2+)-induced Ca2+ release elicited in the presence of extravesicular K+ as counter-ion. This inhibition was not reversed by the addition of valinomycin and still occurred when Cl- was used as co-ion, indicating that not only K+ channels are involved in the inhibiting effect. We found that bisG10 decreased the binding of ryanodine to sarcoplasmic reticulum vesicles, showing that bisG10 is able to block the sarcoplasmic reticulum Ca2+ release channel.
Allard
B
B
Laboratoire de Physiologie des Eléments Excitables, URA 180 CNRS, Villeurbanne, France.
Moutin
M J
MJ
Ronjat
M
M
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects* / Q000378:metabolism; D002712:Chlorides / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006146:Guanidines / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism*; D011817:Rabbits; D012433:Ryanodine / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D014634:Valinomycin / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002712:Chlorides; D006146:Guanidines; D015221:Potassium Channels; C005748:synthalin A; D012433:Ryanodine; D014634:Valinomycin; D011188:Potassium; D002118:Calcium