PMID- 10191357
OWN - NLM
STAT- MEDLINE
DCOM- 19990601
LR  - 20191210
IS  - 0022-2631 (Print)
IS  - 0022-2631 (Linking)
VI  - 168
IP  - 3
DP  - 1999 Apr 1
TI  - Cystic fibrosis transmembrane conductance regulator (CFTR) confers glibenclamide 
      sensitivity to outwardly rectifying chloride channel (ORCC) in Hi-5 insect cells.
PG  - 229-39
AB  - Increasing evidence is now accumulating for the involvement of the cystic 
      fibrosis transmembrane conductance regulator (CFTR) in the control of the 
      outwardly rectifying chloride channel (ORCC). We have examined the sensitivity of 
      ORCC to the sulfonylurea drug glibenclamide in Hi-5 (Trichoplusia ni) insect 
      cells infected with recombinant baculovirus expressing either wild-type CFTR, 
      DeltaF508-CFTR or E. coli beta galactosidase cDNA and in control cells either 
      infected with virus alone or uninfected. Iodide efflux and single channel 
      patch-clamp experiments confirmed that forskolin and 1-methyl-3-isobutyl xanthine 
      (IBMX) or 7-methyl-1,3 dipropyl xanthine (DPMX) activate CFTR channels (unitary 
      conductance: 9.1 +/- 1.6 pS) only in cells expressing CFTR. In contrast, we 
      identified 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid 
      (SITS)-sensitive ORCC in excised membrane patches in any of the cells studied, 
      with similar conductance (22 +/- 2.5 pS at -80 mV; 55 +/- 4.1 pS at +80 mV) and 
      properties. In the presence of 500 microm SITS, channel open probability (Po) of 
      ORCC was reversibly reduced to 0.05 +/- 0.01 in CFTR-cells, to 0.07 +/- 0.02 in 
      non-CFTR expressing cells and to 0.05 +/- 0.02 in DeltaF508-cells. In Hi-5 cells 
      that did not express CFTR, glibenclamide failed to inhibit ORCC activity even at 
      high concentrations (100 microm), whereas 500 microm SITS reversibly inhibited 
      ORCC. In contrast in cells expressing CFTR or DeltaF508, glibenclamide dose 
      dependently (IC50 = 17 microm, Hill coefficient 1.2) and reversibly inhibited 
      ORCC. Cytoplasmic application of 100 microm glibenclamide reversibly reduced Po 
      from 0.88 +/- 0.03 to 0.09 +/- 0.02 (wash: Po = 0.85 +/- 0.1) in CFTR cells and 
      from 0.89 +/- 0.05 to 0.08 +/- 0.05 (wash: Po = 0.87 +/- 0.1) in DeltaF508 cells. 
      In non-CFTR expressing cells, glibenclamide (100 microm) was without effect on Po 
      (control: Po = 0. 89 +/- 0.09, glib.: Po = 0.86 +/- 0.02; wash: Po = 0.87 +/- 
      0.05). These data strongly suggest that the expression of CFTR confers 
      glibenclamide sensitivity to the ORCC in Hi-5 cells.
FAU - Julien, M
AU  - Julien M
AD  - Station de Recherche de Pathologie Comparee INRA-CNRS 30180 
      Saint-Christol-lez-Ales F-30380, France.
FAU - Verrier, B
AU  - Verrier B
FAU - Cerutti, M
AU  - Cerutti M
FAU - Chappe, V
AU  - Chappe V
FAU - Gola, M
AU  - Gola M
FAU - Devauchelle, G
AU  - Devauchelle G
FAU - Becq, F
AU  - Becq F
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Membr Biol
JT  - The Journal of membrane biology
JID - 0211301
RN  - 0 (ATP-Binding Cassette Transporters)
RN  - 0 (CFTR protein, human)
RN  - 0 (Calcium Channels)
RN  - 0 (Chlorides)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 0 (Xanthines)
RN  - 126880-72-6 (Cystic Fibrosis Transmembrane Conductance Regulator)
RN  - 1F7A44V6OU (Colforsin)
RN  - 27816-59-7 (4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid)
RN  - 31542-63-9 (1,3-dipropyl-7-methylxanthine)
RN  - EC 3.2.1.23 (beta-Galactosidase)
RN  - SX6K58TVWC (Glyburide)
RN  - TBT296U68M (1-Methyl-3-isobutylxanthine)
SB  - IM
MH  - 1-Methyl-3-isobutylxanthine/pharmacology
MH  - 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid/pharmacology
MH  - ATP-Binding Cassette Transporters/antagonists & inhibitors
MH  - Animals
MH  - Calcium Channels/*drug effects
MH  - Cells, Cultured
MH  - Chlorides/*metabolism
MH  - Colforsin/pharmacology
MH  - Cystic Fibrosis Transmembrane Conductance Regulator/genetics/*physiology
MH  - Genetic Vectors/genetics
MH  - Glyburide/*pharmacology
MH  - Humans
MH  - Ion Channel Gating/*drug effects
MH  - Moths/drug effects
MH  - Nucleopolyhedroviruses/genetics
MH  - Patch-Clamp Techniques
MH  - Recombinant Fusion Proteins/physiology
MH  - Spodoptera
MH  - Xanthines/pharmacology
MH  - beta-Galactosidase/genetics
EDAT- 1999/04/07 00:00
MHDA- 1999/04/07 00:01
CRDT- 1999/04/07 00:00
PHST- 1999/04/07 00:00 [pubmed]
PHST- 1999/04/07 00:01 [medline]
PHST- 1999/04/07 00:00 [entrez]
AID - 10.1007/s002329900512 [doi]
PST - ppublish
SO  - J Membr Biol. 1999 Apr 1;168(3):229-39. doi: 10.1007/s002329900512.