Académie royale de Médecine de Belgique

|

Résumé de Olivier Devuyst (Séance du 19 juin 2010)

 

WATER TRANSPORT ACROSS BIOLOGICAL MEMBRANES : DOES OVERTON STILL RULE ?  

par  O. DEVUYST (U.C.L.), membre ordinaire.       

One hundred years ago, Overton postulated that the diffusion of a molecule into the cell depends from its selective solubility across the cell membranes, and that the cell permeation rate is largely determined by the lipophilic nature of the molecule. This concept (the “Overton rule”) has evolved over time, and it is now admitted that most molecules playing a role in physiology or pharmacology are transported across biological membranes by specialized proteins (“carriers”) rather than by simple diffusion across the lipid bilayer.

We will illustrate this concept by presenting recent data that point to the role of water channels (“aquaporins”) in various cell types, including epithelial and endothelial cells and macrophages. These studies reveal that water channels play a critical role in multiple organs, not only for maintaining water homeostasis but also for specialized functions including glycerol metabolism, vascular proliferation and host defense mechanisms. Insights into the structure and regulation of these channels open new perspectives for specific therapeutic interventions that are relevant for various diseased states.

________________________

 

­­­­­­­­­­­­­­­­­­­