Related Experiment Videos
Platelet activating factor increases intracellular calcium in isolated osteoclasts but does not modify bone
A L Wucherpfennig1, F E Dewhirst, P Stashenko
1Forsyth Research Institute, Boston, MA 02115.
Bone
|January 1, 1993
Summary
Platelet activating factor (PAF) does not affect bone resorption, even though it increases intracellular calcium in osteoclasts. This suggests that osteoclast regulation may involve signaling pathways independent of calcium levels.
Area of Science:
- Biochemistry
- Cell Biology
- Immunology
Background:
- Platelet activating factor (PAF) is an inflammatory mediator released by activated immune cells.
- Previous studies indicated PAF elevates intracellular calcium in osteoclasts.
Purpose of the Study:
- To investigate the effect of PAF on bone resorption.
- To determine if increased intracellular calcium ([Ca++]i) inhibits osteoclast-mediated bone resorption.
Main Methods:
- Examined PAF's effect on unstimulated and PTH-induced bone resorption.
- Utilized fetal long bone assays.
- Compared PAF effects with calcium ionophores (ionomycin, A23187) and salmon calcitonin.
Main Results:
- PAF did not alter bone resorption.
- Calcium ionophores increased [Ca++]i but did not affect resorption.
- Salmon calcitonin inhibited resorption without altering [Ca++]i.
Conclusions:
- Osteoclast downregulation mechanisms can be independent of intracellular calcium.
- Other signaling pathways likely mediate osteoclast regulation.