Passive permeability of the endoplasmic reticulum of saponin-treated macrophages to Ca 2+ was studied by the filtration method using 45 Ca. The Ca 2+ release from the endoplasmic reticulum of macrophages was enhanced by the presence of submicromolar concentrations of Ca 2+ in the medium. The Ca 2+ release was enhanced by caffeine, and suppressed by MgCl 2 . These phenomena are similar to the Ca 2+ -induced Ca 2+ release reported for the sarcoplasmic reticulum of skeletal muscle. On the other hand, adenine suppressed the Ca 2+ release from the endoplasmic reticulum, while it reportedly enhanced the Ca 2+ -induced Ca 2+ release of the skeletal muscle. The threshold concentration of Ca 2+ for the Ca 2+ -induced Ca 2+ release was approximately 10 -8 M in the presence of 0.95 mM MgCl 2 in macrophages. The spontaneous spreading of macrophages and spontaneous migration of macrophages were inhibited by adenine, and also by caffeine in spite of the enhancement of the Ca 2+ -induced Ca 2+ release.
|Number of pages||9|
|Journal||Journal of biochemistry|
|Publication status||Published - Jan 1 1983|
All Science Journal Classification (ASJC) codes
- Molecular Biology