Related Experiment Videos
A two-step model of secretion control in neuroendocrine cells
C Heinemann1, L von Rüden, R H Chow
1Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
Pflugers Archiv : European Journal of Physiology
|July 1, 1993
Summary
Intense stimuli deplete release-ready granules, depressing neuroendocrine cell secretion. A new model shows both granule consumption and supply must depend on intracellular calcium concentration ([Ca2+]i) to explain this secretory depression.
Area of Science:
- Cellular Biology
- Neuroendocrinology
- Biophysics
Background:
- Neuroendocrine cells exhibit secretory response depression under intense stimulation.
- This depression is often attributed to the depletion of readily releasable granule pools.
Purpose of the Study:
- To develop and validate a two-step model simulating the dynamics of the readily releasable granule pool.
- To investigate the role of intracellular calcium concentration ([Ca2+]i) in secretion dynamics and secretory depression.
Main Methods:
- A two-step model of secretion was developed to simulate granule pool dynamics.
- Model rate constants were derived from experimental data.
- The model was used to simulate secretory responses under various conditions.
Main Results:
- The model demonstrates that both exocytosis (consumption) and vesicle supply to the releasable pool must be calcium-dependent.
- Simulations successfully reproduced various experimental results from the literature.
- The model predicts the occurrence of secretory depression and augmentation.
Conclusions:
- Calcium-dependent regulation of both vesicle consumption and supply is crucial for understanding neuroendocrine secretion dynamics.
- The developed model provides a framework for simulating and predicting secretory behavior, including depression and augmentation.