The permeability of the human red cell to deuterium oxide (heavy water)

✍ Scribed by Daniel M. Karan; Robert I. Macey

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: English
• Weight: 410 KB
• Volume: 104
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041040210

✦ Synopsis

Using a stopped-flow device, the osmotic water permeability of human red cells to D,O and H,O was studied as a function of temperature and under the influence of the sulfhydryl reagent paracholoromercuribenzene sulfonic acid (PCMBS), an inhibitor of water transport. The ratio, permeability (D,O)/ permeability (H,O) at each temperature can be predicted simply by assuming that permeability varies inversely with macroscopic viscosity. When water permeability is inhibited with PCMBS, this dependency on viscosity vanishes; the inhibited permeabilities in D,O and H,O are indistinguishable.

The human red cell membrane has been a favorite prototype of studies of water transport for many years. Although experimental data are frequently interpreted in terms of waterfilled channels ("pores"), progress in characterizing the channels has been slow because they are relatively insensitive to most transport reagents, and because it now appears that they are not traversed by any molecule, aside from water itself. Thus there is a paucity of channel "probes" that can be enlisted in the design of experiments. Given these circumstances, it would be expedient to exploit the small differences in physicochemical properties of D,O and H,O, both of which must have access to the water channels.

Rates of D,O penetration into sheep, beef, and rat red cells have been measured by Brooks ('35) and by Parpart ('35). Both of these studies found a slower penetration by D20,