Abstract
ATP dependent Ca2+ accumulation into oxalate-loaded rat brain microsomes is potently inhibited by thapsigargin with an IC50 of 2 nM and maximal inhibition at 10 nM. Approximately 15% of the total A23187-releasable microsomal calcium store is insensitive to thapsigargin concentrations up to 100 microM. Inositol-1,4,5-trisphosphate (IP3) maximally inhibits 40% of the net Ca2+ accumulation by whole brain microsomes. Its effects are non-additive with thapsigargin suggesting that the IP3-sensitive Ca2+ pool is a subset of the thapsigargin sensitive Ca2+ pool. Marked regional differences occur in Ca2+ transport rates and sensitivity to both thapsigargin and IP3.
| Original language | English |
|---|---|
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 172 |
| Issue number | 2 |
| Pages (from-to) | 811-6 |
| Number of pages | 6 |
| ISSN | 0006-291X |
| Publication status | Published - 1990 |
Keywords
- Animals
- Brain
- Calcimycin
- Calcium
- Carcinogens
- Endoplasmic Reticulum
- Heparin
- Inositol 1,4,5-Trisphosphate
- Kinetics
- Microsomes
- Organ Specificity
- Rats
- Terpenes
- Thapsigargin