PMID- 7491280
OWN - NLM
STAT- MEDLINE
DCOM- 19960104
LR  - 20190726
IS  - 0031-6768 (Print)
IS  - 0031-6768 (Linking)
VI  - 430
IP  - 4
DP  - 1995 Aug
TI  - Neuropeptide Y2-type receptor-mediated activation of large-conductance 
      Ca(2+)-sensitive K+ channels in a human neuroblastoma cell line.
PG  - 534-40
AB  - We have proposed recently that a pertussistoxin-insensitive Ca2+ influx 
      stimulated by Y2-type receptor activation in CHP-234 human neuroblastoma cells 
      underlies increases in intracellular free Ca2+ concentration ([Ca2+]i) induced by 
      neuropeptide Y (NPY), which were strictly dependent on extracellular Ca2+ and 
      independent of internal Ca2+ stores. We describe here the actions of NPY in these 
      same cells, using the activity of Ca(2+)-activated K+ channels as an indicator of 
      [Ca2+]i. The elementary slope conductance of these channels was 110 +/- 3 pS 
      (with an asymmetrical K+ gradient), their activity was greatly increased by 
      application of ionomycin, and they were reversibly blocked by 1 mM 
      tetraethylammonium (TEA) and 100 nM charybdotoxin. Application of 100 nM NPY, in 
      the presence but not in the absence of extracellular Ca2+, increased the channel 
      open probability. ATP applied in the absence of external Ca2+ caused rises both 
      in channel open probability and [Ca2+]i. Inositol trisphosphate production was 
      stimulated by ATP but not by NPY. In outside-out patches, NPY increased channel 
      open probability, indicating that NPY-associated Ca2+ influx does not require all 
      the intracellular machinery present in intact cells. Channel activation by NPY 
      was unaffected by the replacement of guanosine 5'-triphosphate (GTP) by 
      (guanosine 5'-O-(2-thiodiphosphate) (GDP[ beta S]), a non-hydrolysable GDP 
      analogue, in the pipette internal solution, consistent with the lack of 
      involvement of G-proteins in the coupling of Y2-type receptors to Ca2+ influx in 
      CHP-234 cells.
FAU - Lemos, V S
AU  - Lemos VS
AD  - Universite Louis Pasteur de Strasbourg, Laboratoire de Pharmacologie Cellulaire 
      et Moleculaire-CNRS URA600, Illkirch, France.
FAU - Takeda, K
AU  - Takeda K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Pflugers Arch
JT  - Pflugers Archiv : European journal of physiology
JID - 0154720
RN  - 0 (Ionophores)
RN  - 0 (Potassium Channels)
RN  - 0 (Receptors, Neuropeptide Y)
RN  - 0 (Thionucleotides)
RN  - 132-06-9 (Inosine Triphosphate)
RN  - 146-91-8 (Guanosine Diphosphate)
RN  - 56092-81-0 (Ionomycin)
RN  - 71376-97-1 (guanosine 5'-O-(2-thiodiphosphate))
RN  - 85166-31-0 (Inositol 1,4,5-Trisphosphate)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - EC 3.6.1.- (GTP-Binding Proteins)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Adenosine Triphosphate/pharmacology
MH  - Brain Neoplasms/*metabolism
MH  - Calcium/*physiology
MH  - Electrophysiology
MH  - GTP-Binding Proteins/metabolism
MH  - Guanosine Diphosphate/analogs & derivatives/pharmacology
MH  - Humans
MH  - Inosine Triphosphate/pharmacology
MH  - Inositol 1,4,5-Trisphosphate/pharmacology
MH  - Ionomycin/pharmacology
MH  - Ionophores/pharmacology
MH  - Neuroblastoma/*metabolism
MH  - Patch-Clamp Techniques
MH  - Potassium Channels/*metabolism
MH  - Receptors, Neuropeptide Y/*metabolism
MH  - Thionucleotides/pharmacology
MH  - Tumor Cells, Cultured
EDAT- 1995/08/01 00:00
MHDA- 1995/08/01 00:01
CRDT- 1995/08/01 00:00
PHST- 1995/08/01 00:00 [pubmed]
PHST- 1995/08/01 00:01 [medline]
PHST- 1995/08/01 00:00 [entrez]
AID - 10.1007/BF00373890 [doi]
PST - ppublish
SO  - Pflugers Arch. 1995 Aug;430(4):534-40. doi: 10.1007/BF00373890.