Role of water and electrolyte influxes in anoxic plasma membrane disruption.

Abstract

The role of water and electrolyte influxes in anoxia-induced plasma membrane disruption was investigated using rabbit proximal tubule suspension. The results indicated that normal proximal tubule (PT) cells have a great capacity for expanding cell volume in response to water influx, whereas anoxia increases the susceptibility to water influx-induced disruption, and this was attenuated by glycine. However, resistance of anoxic plasma membranes to water influx-induced stress is not lost, although their mechanical strength was diminished, compared with normoxic membranes. Anoxic membranes did not disrupt under an intra-to-extracellular osmotic difference as great as 150 mosM. Potentiating or attenuating water influx by incubating PT cells in hypotonic or hypertonic medium, respectively, during anoxia, did not affect anoxia-induced membrane disruption. After the transmembrane electrolyte concentration gradient was eliminated by a "intracellular" buffer or by permeabilizing the plasma membrane to molecules <4 kDa using alpha-toxin, anoxia still caused further membrane disruption that was prevented by glycine or low pH. These results demonstrate that 1) water or net electrolyte influxes are probably not a primary cause for anoxia-induced membrane disruption and 2) glycine could prevent the plasma membrane disruption during anoxia independently from its effect on transmembrane electrolyte or water influxes. The present data support a biochemical rather than a mechanical alteration of the plasma membrane as the underlying cause of membrane disruption during anoxia.

• Authors: J Chen, L J Mandel
• Journal: The American journal of physiology (Am J Physiol) Vol. 273 Issue 4 Pg. C1341-8 (10 1997) ISSN: 0002-9513 [Print] United States
• PMID: 9357779 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Electrolytes
• L-Lactate Dehydrogenase
• Type C Phospholipases

Topics

• Animals
• Cell Hypoxia
• Cell Membrane (drug effects, physiology, ultrastructure)
• Cells, Cultured
• Electrolytes (metabolism)
• Extracellular Space (physiology)
• Female
• Intracellular Fluid (physiology)
• Kidney Cortex (cytology, physiology)
• Kidney Tubules, Proximal (cytology, physiology)
• Kinetics
• L-Lactate Dehydrogenase
• Osmolar Concentration
• Rabbits
• Type C Phospholipases (pharmacology)