PMID- 11571484
OWN - NLM
STAT- MEDLINE
DCOM- 20020219
LR  - 20191025
IS  - 0958-0670 (Print)
IS  - 0958-0670 (Linking)
VI  - 86
IP  - 5
DP  - 2001 Sep
TI  - The presence of NHE1 and NHE3 Na+-H+ exchangers and an apical cAMP-independent 
      Cl- channel indicate that both absorptive and secretory functions are present in 
      calf gall bladder epithelium.
PG  - 571-83
AB  - We investigated the transport systems that can sustain Na+ and Cl- movements 
      across bovine gall bladder epithelium, focusing on the Na+-H+ exchanger (NHE) 
      family and chloride conductive pathways. Experiments conducted using the 
      fluorescent probe acridine orange (AO) with brush-border membrane vesicles (BBMV) 
      or vesicles obtained from the total epithelium (EMV) demonstrated the presence of 
      a Na+-H+ exchange in both preparations. The use of specific inhibitors indicated 
      the presence of an apical NHE3 exchanger and a NHE1 isoform which should reside 
      in the basolateral membrane. Using reverse transcriptase (RT) PCR, we identified 
      cDNA fragments corresponding to the NHE1, NHE3, Cl--HCO3- (AE2a) transporters and 
      to the CFTR channel. Using the patch-clamp technique, we investigated Cl- 
      conductances on cultured epithelial cells. We found a 5 pS Cl- channel with a 
      voltage-independent open probability, insensitive to stilbenes (SITS), Zn2+ and 
      cAMP. The results suggest that absorption and secretion coexist in calf gall 
      bladder epithelium. A Na+-H+-Cl--HCO3- double exchange may, at least partially, 
      sustain the absorptive function, and a Cl- apical conductive pathway may be 
      involved in secretion. The conductance we observed does not seem to be 
      cAMP-regulated, unlike other mammalian gall bladders.
FAU - Bazzini, C
AU  - Bazzini C
AD  - Department of General Physiology and Biochemistry, University of Milan, Via 
      Celoria 26, 20133 Milan, Italy.
FAU - Botta, G
AU  - Botta G
FAU - Meyer, G
AU  - Meyer G
FAU - Baroni, M D
AU  - Baroni MD
FAU - Paulmichl, M
AU  - Paulmichl M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Exp Physiol
JT  - Experimental physiology
JID - 9002940
RN  - 0 (Anion Transport Proteins)
RN  - 0 (Antiporters)
RN  - 0 (CFTR protein, human)
RN  - 0 (Chloride Channels)
RN  - 0 (Diuretics)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Fluorescent Dyes)
RN  - 0 (Membrane Proteins)
RN  - 0 (Protein Isoforms)
RN  - 0 (SLC4A Proteins)
RN  - 0 (SLC9A3 protein, human)
RN  - 0 (Sodium-Hydrogen Exchanger 3)
RN  - 0 (Sodium-Hydrogen Exchangers)
RN  - 0 (growth factor-activatable Na-H exchanger NHE-1)
RN  - 126880-72-6 (Cystic Fibrosis Transmembrane Conductance Regulator)
RN  - 27816-59-7 (4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid)
RN  - 7DZO8EB0Z3 (Amiloride)
RN  - 7YNJ3PO35Z (Hydrogen)
RN  - 9NEZ333N27 (Sodium)
RN  - E0399OZS9N (Cyclic AMP)
RN  - F30N4O6XVV (Acridine Orange)
RN  - J41CSQ7QDS (Zinc)
SB  - IM
MH  - 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid/pharmacology
MH  - Acridine Orange/metabolism
MH  - Amiloride/pharmacology
MH  - Amino Acid Sequence
MH  - Animals
MH  - *Anion Transport Proteins
MH  - *Antiporters
MH  - Biological Transport/physiology
MH  - Cattle
MH  - Cell Fractionation
MH  - Cell Membrane/*metabolism
MH  - Cell Polarity
MH  - Cells, Cultured
MH  - Chloride Channels/*metabolism
MH  - Cyclic AMP/metabolism/pharmacology
MH  - Cystic Fibrosis Transmembrane Conductance Regulator/chemistry/genetics/metabolism
MH  - Diuretics/pharmacology
MH  - Dose-Response Relationship, Drug
MH  - Enzyme Inhibitors/pharmacology
MH  - Epithelial Cells/cytology/drug effects/*metabolism
MH  - Fluorescent Dyes/metabolism
MH  - Gallbladder/*metabolism
MH  - Humans
MH  - Hydrogen/metabolism
MH  - Male
MH  - Membrane Proteins/chemistry/genetics/metabolism
MH  - Microvilli/metabolism
MH  - Molecular Sequence Data
MH  - Patch-Clamp Techniques
MH  - Protein Isoforms
MH  - SLC4A Proteins
MH  - Sequence Alignment
MH  - Sodium/metabolism
MH  - Sodium-Hydrogen Exchanger 3
MH  - Sodium-Hydrogen Exchangers/antagonists & 
      inhibitors/chemistry/genetics/*metabolism
MH  - Zinc/pharmacology
EDAT- 2001/09/26 10:00
MHDA- 2002/02/20 10:01
CRDT- 2001/09/26 10:00
PHST- 2001/09/26 10:00 [pubmed]
PHST- 2002/02/20 10:01 [medline]
PHST- 2001/09/26 10:00 [entrez]
AID - EPH_2267 [pii]
AID - 10.1113/eph8602267 [doi]
PST - ppublish
SO  - Exp Physiol. 2001 Sep;86(5):571-83. doi: 10.1113/eph8602267.