Permeability of red blood cell membrane to CO2

Range >1 Table - link cm/sec
Organism Human Homo sapiens
Reference Forster RE, Gros G, Lin L, Ono Y, Wunder M. The effect of 4,4'-diisothiocyanato-stilbene-2,2'-disulfonate on CO2 permeability of the red blood cell membrane. Proc Natl Acad Sci U S A. 1998 Dec 22 95(26):15815-20. p.15818 table 1PubMed ID9861053
Method P.15815 right column 3rd paragraph: "The reactions take place in an airtight 3-ml glass water-jacketed and stirred chamber connected to the ion source of a mass spectrometer through a thin 0.012-mm-thick Teflon membrane supported by a sintered glass disc, through which gases are dissolved in the solution diffuse. The chamber has a glass pH electrode and a removable stopper for the addition of reactants."
Comments P.15817 right column bottom paragraph: "Typical experimental records and calculated time courses are shown in Fig. 4 for a control experiment and for an experiment with DIDS. Note that the rapid phase is noticeably slower in the presence of DIDS, indicating a decreased Pm,CO2. Because the rate of 18O exchange in the fast phase is at least an order of magnitude greater than in the slow phase and depends mainly on CA activity and Pm,CO2, and because there is initially no gradient of labeled HCO3− across the cell so that no anion exchange occurs, the effect of a decrease in Pm,CO2 is more noticeable. The results of the new calculations on eight experiments analogous to those in Fig. 4 are summarized in Table 1. DIDS (100µM) did not alter the calculated CA [carbonic anhydrase] activity in the intact red cells, but did lower Pm,HCO3- to about half. The interesting finding is that membrane CO2 permeability, from a value of 1cm/sec or higher in the control experiments, was lowered by the drug to a value of 0.1cm/sec."
Entered by Uri M
ID 110615