부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.tracli.2006.02.007 Byline: V. Endeward (a), J.-P. Cartron (b), P. Ripoche (b), G. Gros (a) Keywords: Membrane CO.sub.2 permeability; Human red cells; Aquaporin-1; Rh proteins; Blood group deficiencies Abstract: The red cell membrane has an exceptionally high permeability for CO.sub.2, P.sub.CO2 [approximately equal to]0.15 cm/s, which is two to three orders of magnitude greater than that of some epithelial membranes and similarly greater than the permeability of the red cell membrane for HCO.sub.3.sup.-. As shown previously, this high P.sub.CO2 can be drastically inhibited by 10 [mu]M 4,4'-diisothiocyanato-2,2'-stilbenedisulfonate (DIDS), indicating that membrane proteins may be involved in this high gas permeability. Here, we have studied the possible contribution of several blood group proteins to CO.sub.2 permeation across the red cell membrane by comparing P.sub.CO2 of red cells deficient in specific blood group proteins with that of normal red cells. While P.sub.CO2 of normal red cells is ~0.15 cm/s and that of Fy.sub.null and Jk.sub.null red cells is similar, P.sub.CO2's of Colton null (deficient in aquaporin-1) and Rh.sub.null cells (deficient in Rh/RhAG) are both reduced to about 0.07 cm/s, i.e. to about one half. In addition, the inhibitory effect of DIDS is about half as great in Rh.sub.null and in Colton null red cells as it is in normal red cells. We conclude that aquaporin-1 and Rh/RhAG proteins contribute substantially to the high permeability of the human red cell membrane for CO.sub.2. Together these proteins are responsible for 50% or more of the CO.sub.2 permeability of red cell membranes. The CO.sub.2 pathways of both proteins can be partly inhibited by DIDS, which is why this compound very effectively reduces membrane CO.sub.2 permeability. Author Affiliation: (a) Zentrum Physiologie, Medizinische Hochschule Hannover, 30625 Hannover, Germany (b) Inserm U665 Paris, Institut national de la transfusion sanguine, 6, rue Alexandre-Cabanel, 75015 Paris, France