PMID- 7491265
OWN - NLM
STAT- MEDLINE
DCOM- 19960104
LR  - 20190726
IS  - 0031-6768 (Print)
IS  - 0031-6768 (Linking)
VI  - 430
IP  - 3
DP  - 1995 Jul
TI  - ADP exerts a protective effect against rundown of the Ca2+ current in bovine 
      chromaffin cells.
PG  - 401-9
AB  - In isolated chromaffin cells, the high-voltage-activated Ca2+ current, recorded 
      using 5 mM Ca2+ as the divalent charge carrier, exhibits rundown within 10 min, 
      which is delayed for 1 h at least by the addition of 1 mM adenosine 
      5'-triphosphate (ATP) to the pipette medium. The mechanism of this stabilizing 
      action of ATP has been examined. ATP action is dose dependent; the rundown 
      process, which was delayed at concentrations below 0.4 mM, was totally abolished 
      at higher concentrations. The requirement for ATP was shown to be quite strict: 2 
      mM inosine 5'-triphosphate (ITP) could not replace ATP, whereas guanosine 
      5'-triphosphate (GTP) could, but at higher concentrations. This effect of ATP was 
      shown to require the presence of MgCl2 and the liberation of a phosphate group 
      since the ATP analogue 5'-adenylyl-imidodiphosphate (AMP-PNP) could not act as a 
      substitute for ATP, suggesting an action through either adenosine 5'-diphosphate 
      (ADP) or a phosphorylation step. ADP, in the presence of Mg2+ only, could replace 
      ATP in the same concentration range. This effect was shown to be specific to ADP; 
      it was maintained after blocking the pathways which convert ADP into ATP, and 
      could not be mimicked by guanosine 5'-diphosphate (GDP). Similarly, ATP and ADP 
      effects were abolished at an increased internal Ca2+ concentration (pCa 6 instead 
      of pCa 7.7, where pCa = -log10[Ca2+]). Nevertheless, the presence of 1 mM Mg-ADP 
      in the bathing solution did not prevent the rundown of the Ca2+ channels when 
      going to the inside-out patch recording configuration.(ABSTRACT TRUNCATED AT 250 
      WORDS)
FAU - Elhamdani, A
AU  - Elhamdani A
AD  - Laboratorie de Neurobiologie Cellulaire, UPR 9009, CNRS associe a l'Universite 
      Louis Pasteur, Strasbourg, France.
FAU - Bossu, J L
AU  - Bossu JL
FAU - Feltz, A
AU  - Feltz A
LA  - eng
PT  - Journal Article
PL  - Germany
TA  - Pflugers Arch
JT  - Pflugers Archiv : European journal of physiology
JID - 0154720
RN  - 0 (Calcium Channels)
RN  - 0 (Nucleotides)
RN  - 61D2G4IYVH (Adenosine Diphosphate)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - EC 2.7.- (Protein Kinases)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Adenosine Diphosphate/metabolism/*pharmacology
MH  - Adenosine Triphosphate/metabolism/pharmacology
MH  - Animals
MH  - Binding Sites/drug effects
MH  - Brain/enzymology
MH  - Calcium/metabolism
MH  - Calcium Channels/drug effects/*metabolism
MH  - Cattle
MH  - Chromaffin System/drug effects/*metabolism
MH  - Electrophysiology
MH  - Hydrolysis
MH  - Nucleotides/pharmacology
MH  - Protein Kinases/metabolism
EDAT- 1995/07/01 00:00
MHDA- 1995/07/01 00:01
CRDT- 1995/07/01 00:00
PHST- 1995/07/01 00:00 [pubmed]
PHST- 1995/07/01 00:01 [medline]
PHST- 1995/07/01 00:00 [entrez]
AID - 10.1007/BF00373916 [doi]
PST - ppublish
SO  - Pflugers Arch. 1995 Jul;430(3):401-9. doi: 10.1007/BF00373916.