Protoplasmic Swelling as a Symptom of Freezing Injury in Onion Bulb Cells 1: Its Simulation in Extracellular KCl and Prevention by Calcium
AUTOR(ES)
Arora, Rajeev
RESUMO
Freezing injury, in onion bulb tissue, is known to cause enhanced K+ efflux accompanied by a small but significant loss of Ca2+ following incipient freezing injury and swelling of protoplasm during the postthaw secondary injury. The protoplasmic swelling of the cell is thought to be caused by the passive influx of extracellular K+ into the cell followed by water uptake. Using outer epidermal layer of unfrozen onion bulb scales (Allium cepa L. cv Big Red), we were able to stimulate the irreversible freezing injury symptoms, by bathing epidermal cells in 50 millimolar KCl. These symptoms were prevented by adding 20 millimolar CaCl2 to the extracellular KCl solution. Our results provide evidence that loss of cellular Ca2+ plays an important role in the initiation and the progression of freezing injury.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1056174Documentos Relacionados
- Protoplasmic Swelling as a Symptom of Freezing Injury in Onion Bulb Cells
- In Vivo Perturbation of Membrane-Associated Calcium by Freeze-Thaw Stress in Onion Bulb Cells 1: Simulation of This Perturbation in Extracellular KCl and Alleviation by Calcium
- Freezing Injury in Onion Bulb Cells: II. Post-thawing Injury or Recovery1
- Freezing Injury in Onion Bulb Cells: I. Evaluation of the Conductivity Method and Analysis of Ion and Sugar Efflux from Injured Cells1
- An ATP-activated conductance in pheochromocytoma cells and its suppression by extracellular calcium.
