Failure of inositol 1,4,5-trisphosphate to elicit or potentiate Ca2+ release from isolated skeletal muscle sarcoplasmic reticulum.
This study was conducted to resolve the conflicting reports regarding the ability of inositol 1,4,5-trisphosphate (IP3) to elicit the release of Ca2+ from isolated sarcoplasmic reticulum derived from skeletal muscle. Three different conditions were employed, one of which has been reported to produce an IP3 induced release of Ca2+. Sarcoplasmic reticulum vesicles with and without intact feet structures failed to respond to added IP3. In addition, IP3 had no effect on the Ca2+-induced release of Ca2+. These results suggest that, unlike other tissue, IP3 does not mobilize the release of Ca2+ from skeletal muscle sarcoplasmic reticulum. IP3 is therefore unlikely to be the physiological signal linking transverse-tubule depolarization with Ca2+ release from the sarcoplasmic reticulum.
D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D004357:Drug Synergism; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology*; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013403:Sugar Phosphates / Q000494:pharmacology*
D007295:Inositol Phosphates; D013403:Sugar Phosphates; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium