The Response of Chloride Transport to Cyclic AMP, Calcium and Hypotonic Shock in Normal and Cystic Fibrosis Fibroblasts

  • Teresa Mastrocola
  • Michela Rugolo
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 290)


Cl- transport was shown to be altered in skin fibroblasts from cystic fibrosis (CF) patients (Rugolo et al.,1986), and an abnormal Cl- metabolism was also observed by Mattes et al. (1987). In the present study we have investigated the effect of two cAMP analogs, 8-Bromo cyclic AMP (8-Br-cAMP) and dibutyryl cyclic AMP (dbt-cAMP), of a beta agonist, isoproterenol, on 36C1- efflux from normal and CF fibroblasts. Cl- efflux consists of a superposition of two efflux events, operationally defined as two compartments, each exhibiting first order exponential decay. In table 1 it is shown that 15 min preincubation in the presence of cAMP analogs (O.lmM 8-Br-cAMP and ImM dbt-cAMP) and isoproterenol (5µM) increased the rate constant (k) of Cl-efflux from the fast compartment of 10%, 5% and 9% respectively, in both normal and CF fibroblasts. These results are in disagreement with those previously reported by Lin and Gruenstein, 1987, who observed a 13% stimulation of Cl- efflux in normal fibroblasts, but failed to detect any activation in CF cells. However, in our experiments, the extent of activation of Cl- transport by the cAMP-dependent effectors was weak in control cells, so that no difference could be detected between normal and CF fibroblasts.


Cystic Fibrosis Normal Fibroblast Beta Agonist Chloride Transport cAMP Analog 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Lin, P. and Gruenstein, E., 1987, Identification of a defective cAMP-stimulated Cl-channel in cystic fibrosis fibro blasts, J. Biol. Chem., 262:15345.PubMedGoogle Scholar
  2. Mattes, P.M., Maloney, P.C. and Littlefield, J.W., 1987, Altered chloride metabolism in cultured cystic fibrosis skin fibroblasts, Proc. Natl. Acad. Sci. USA, 84:3009.PubMedCrossRefGoogle Scholar
  3. Rugolo, M., Romeo, G. and Lenaz, G., 1986, Kinetic analysis of chloride efflux from normal and cystic fibrosis fibroblasts, Biochem. Biophys. Res. Comm.,160:1330.CrossRefGoogle Scholar
  4. Rugolo, M., Mastrocola, T., Flamigni, A. and Lenaz, G., 1989, Chloride transport in human fibroblasts is activated by hypotonic shock, Biochem. Biophys. Res. Comm., 160:1330.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • Teresa Mastrocola
    • 1
  • Michela Rugolo
    • 1
  1. 1.Dip. di Biologia Ev.Sp.Universita’ di BolognaBolognaItaly

Personalised recommendations