2,2,4-Trimethylpentane induces Ca2+ release from the sarcoplasmic reticulum terminal cisterns.
Using quin2, the effects of aliphatic hydrocarbons on the system of Ca(2+)-induced Ca2+ release in isolated membranes of rabbit skeletal muscle terminal cisterns have been studied. The hydrocarbons were inserted into the membranes by means of hydrocarbon-containing liposomes. 2,2,4-Trimethylpentane (isooctane) caused a rapid release of 70-75% of Ca2+ taken up by the terminal cistern vesicles during the Ca(2+)-pump operation. This effect was inhibited by the caffeine-induced Ca2+ release blockers--Mg2+, ruthenium red and tetracaine. The same was observed with a decrease in the concentration of ATP that is known to activate the terminal cistern Ca2+ channels. The effect of 2,2,4-trimethylpentane on the longitudinal cistern fractions practically devoid of Ca(2+)-channels was insignificant. Heptane, hexane and octane caused a slow release of 5-10% of the accumulated Ca2+ from the terminal cistern vesicles; no such effect was induced by decane.
Ritov
V B
VB
School of Biology, M.V. Lomonosov Moscow State University, U.S.S.R.
Men'shikova
E V
EV
D000255:Adenosine Triphosphate / Q000378:metabolism; D000634:Aminoquinolines; D000818:Animals; D001588:Benzoylcholine / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002413:Cations, Divalent; D005456:Fluorescent Dyes; D006868:Hydrolysis; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D009795:Octanes / Q000494:pharmacology*; D011817:Rabbits; D012430:Ruthenium Red / Q000494:pharmacology; D012519:Sarcoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D013748:Tetracaine / Q000494:pharmacology
D000634:Aminoquinolines; D002413:Cations, Divalent; D005456:Fluorescent Dyes; D009795:Octanes; D013748:Tetracaine; D012430:Ruthenium Red; D001588:Benzoylcholine; D002110:Caffeine; D000255:Adenosine Triphosphate; D008274:Magnesium; C035739:Quin2; C045798:2,2,4-trimethylpentane; D002118:Calcium